Evaluation of algorithms to identify delirium in administrative claims and drug utilization database

Development and validation of a machine learning model to predict postoperative delirium using a nationwide database: A retrospective, observational study

STUDY OBJECTIVE

Postoperative delirium is a neuropsychological syndrome that typically occurs in surgical patients. Its onset can lead to prolonged hospitalization as well as increased morbidity and mortality. Therefore, it is important to promptly identify its signs. This study aimed to develop and validate a machine learning predictive model for postoperative delirium using extensive population data.

DESIGN

Retrospective observational study.

SETTING

Japanese Diagnosis Procedure Combination inpatient data. Data were used for internal (2016.4-2018.12) and temporal validation (2019.01-2019.10).

PATIENTS

Patients aged ≥65 years who underwent general anesthesia for surgical procedure.

MEASUREMENTS

The primary outcome was postoperative delirium, which was defined as a condition requiring newly prescribed antipsychotic drugs or assignment of the corresponding insurance claim code after the date of surgery. We trained and tuned the optimal machine-learning model through 10-fold cross-validation using the selected optimal area under the receiver operating characteristic curve (AUC) value. In the temporal validation, we measured the performance of our model.

MAIN RESULTS

The analysis included 557,990 patients. The light-gradient boosting machine models showed a higher AUC value (0.826 [95% confidence interval (CI): 0.822-0.829]) than the other models. Regarding performance, the model had a recall value of 0.124 (95% CI: 0.119-0.129) and precision value of 0.659 (95% CI: 0.641-0.677]). This performance was sustained in the temporal validation (AUC, 0.815 [95% CI: 0.811-0.818]). At a sensitivity of 0.80, the model achieved a specificity of 0.672 (95% CI: 0.670-0.674]), a negative predictive value of 0.975 (95% CI: 0.974-0.975), and a positive predictive value of 0.176 (95% CI: 0.176-0.179).

CONCLUSIONS

Using extensive Diagnostic Procedure Combination data, we successfully created and validated a machine learning model for predicting postoperative delirium. This model may facilitate prediction of postoperative delirium.

Crosswalk Algorithms for Cognitive and Functional Outcomes Among 2013-2018 Medicare Beneficiaries With Dementia

OBJECTIVE

Before 2019, the Minimum Data Set (MDS) and Outcome and Assessment Information Set (OASIS) had incongruent response categories for rating cognitive impairment and activities of daily living (ADLs), hindering direct comparisons between nursing facilities and home health. We devised rule-based algorithms to compare cognitive impairment and ADL limitations between these 2 care settings among people with Alzheimer's disease and Alzheimer's disease-related dementias (ADRD).

DESIGN

A retrospective cohort study.

SETTING AND PARTICIPANTS

Included fee-for-service Medicare beneficiaries (2013-2018) transitioning from nursing facilities to home health, with 1-year of continuous enrollment, aged ≥65 years, diagnosed ADRD, and with complete MDS discharge and OASIS admission assessments (N = 398,496).

METHODS

We identified target phenotypes using the Cognitive Function Scale (CFS) and ADL items from the MDS discharge assessment as reference standards. We compared 6 OASIS-based algorithms for cognitive impairment and 1 for each ADL limitation by estimating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The average age was 83.5 (SD = 7.5) years and 82.3% transitioned from nursing to home health within 3 days. In the MDS discharge assessment, 42.2% had moderate-to-severe cognitive impairment. ADL limitations ranged from 71.4% for feeding to 97.8% for bathing. Compared with the moderate-to-severe cognitive impairment (CFS ≥3) on the MDS, the OASIS cognitive assessment indicating "considerable assistance to total dependence in routine situations" had 24% sensitivity, 94% specificity, 75% PPV, and 63% NPV. The ADL limitation algorithms exhibited high sensitivities (>96%) and PPVs (>94%) except for feeding (Sensitivity: 82%; PPV: 74%). Despite the short time frame between the 2 assessments, the OASIS admission assessment showed a higher prevalence of ADL limitations than the MDS discharge assessment.

CONCLUSIONS AND IMPLICATIONS

We highlighted differences in patient function between post-acute care settings. Our algorithms can help researchers, clinicians, and policymakers standardize patient-centered outcomes for comparative effectiveness research or quality initiatives.

Postoperative use of sleep aids and delirium in older adults after major surgery: A retrospective cohort study

BACKGROUND

Sleep aids are commonly prescribed to treat sleep disturbance, a modifiable risk factor for postoperative delirium in older patients. The use of melatonin receptor agonists in the postoperative period has been increasing. The comparative safety of melatonin receptor agonists, zolpidem, and temazepam remains uncertain.

METHODS

This retrospective study included 22,083 patients ≥65 years old who initiated melatonin receptor agonists, zolpidem, or temazepam after major surgery in the Premier Healthcare Database 2009-2018. We performed propensity score-based overlap weighting and estimated the risk ratio (RR) and risk difference (RD) of postoperative delirium as the primary outcome and a composite of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality as secondary outcomes.

RESULTS

The mean age of the study population was 78 (SD, 7) years and 50% were female. There was no significant difference in the risk of postoperative delirium among patients treated with melatonin receptor agonists (3.4%, reference group), zolpidem (2.9%; RR [95% CI], 0.9 [0.7-1.2]; RD [95% CI] per 100 persons, -0.3 [-1.1 to 0.6]), and temazepam (3.1%; 0.9 [0.7-1.1]; RD [95% CI] per 100 persons, -0.5 [-1.2 to 0.3]). The risks of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality were also similar among all groups.

CONCLUSIONS

Melatonin receptor agonists were not associated with a lower risk of postoperative delirium and other adverse outcomes compared with zolpidem and temazepam in older adults after major surgery.

Association between hospital palliative care team intervention volume and patient outcomes

BACKGROUND

The benefits of palliative care in patients with advanced cancer are well established. However, the effect of the skills of the palliative care team (PCT) on patient outcomes remains unclear. Our aim was to evaluate the association between hospital PCT intervention volume and patient outcomes in patients with cancer.

METHODS

A retrospective cohort study was conducted using a nationwide inpatient database in Japan. Patients with cancer receiving chemotherapy and PCT intervention from 2015 to 2020 were included. The outcomes were incidence of hyperactive delirium within 30 days of admission, mortality within 30 days of admission, and decline in activities of daily living (ADL) at discharge. The exposure of interest was hospital PCT intervention volume (annual number of new PCT interventions in a hospital), which was categorized into low-, intermediate-, and high-volume groups according to tertiles. Multivariate logistic regression and restricted cubic-spline regression were conducted.

RESULTS

Of 29,076 patients, 1495 (5.1%), 562 (1.9%), and 3026 (10.4%) developed delirium, mortality, and decline in ADL, respectively. Compared with the low hospital PCT intervention volume group (1-103 cases/year, n = 9712), the intermediate (104-195, n = 9664) and high (196-679, n = 9700) volume groups showed significant association with lower odds ratios of 30-day delirium (odds ratio, 0.79 [95% confidence interval, 0.69-0.91] and 0.80 [0.69-0.93], respectively), 30-day mortality (0.73 [0.60-0.90] and 0.59 [0.46-0.75], respectively), and decline in ADL (0.77 [0.70-0.84] and 0.52 [0.47-0.58], respectively).

CONCLUSION

Hospital PCT intervention volume is inversely associated with the odds ratios of delirium, mortality, and decline in ADL among hospitalized patients with cancer.

Clinical Outcomes Following Operative and Nonoperative Management of Odontoid Fractures Among Elderly Individuals with Dementia

BACKGROUND

The incidence of odontoid fractures among the elderly population has been increasing in recent years. Elderly individuals with dementia may be at increased risk for inferior outcomes following such fractures. Although surgical intervention has been maintained to optimize survival and recovery, it is unclear if this benefit extends to patients with dementia. We hypothesized that patients with dementia who were treated operatively for odontoid fractures would experience improved survival and lower rates of hospice admission but higher rates of delirium and of intensive interventions.

METHODS

We used Medicare claims data (2017 to 2018) to identify community-dwelling individuals with dementia who sustained type-II odontoid fractures. We considered treatment strategy (operative or nonoperative) as the primary predictor and survival as the primary outcome. The secondary outcomes consisted of post-treatment delirium, hospice admission, post-treatment intensive intervention, and post-discharge admission to a nursing home or a skilled nursing facility. In all models, we controlled for age, biological sex, race, Elixhauser Comorbidity Index, Frailty Index, admission source, treating hospital, and dual eligibility. Adjusted analyses for survival were conducted using Cox proportional hazards regression. Adjusted analyses for secondary outcomes were performed using generalized estimating equations. To address confounding by indication, we performed confirmatory analyses using inverse probability of treatment weighting.

RESULTS

In this study, we included 1,030 patients. The median age of the cohort was 86.5 years (interquartile range, 80.9 to 90.8 years), 60.7% of the patients were female, and 90% of the patients were White. A surgical procedure was performed in 19.8% of the cohort. Following an adjusted analysis, patients treated surgically had a 28% lower hazard of mortality (hazard ratio, 0.72 [95% confidence interval (CI), 0.53 to 0.98]), but higher odds of delirium (odds ratio, 1.64 [95% CI, 1.10 to 2.44]). These findings were preserved in the inverse probability weighted analysis.

CONCLUSIONS

We found that, among individuals with dementia who sustain a type-II odontoid fracture, surgical intervention may confer a survival benefit. A surgical procedure may be an appropriate treatment strategy for individuals with dementia whose life-care goals include life prolongation and maximizing quality of life in the short term following an injury.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Mediation Analysis Examining High Risk, Anticholinergic Medication Use, Delirium, and Dementia After Major Surgery

INTRODUCTION

Anticholinergic medications are known to cause adverse cognitive effects in community-dwelling older adults and medical inpatients, including dementia. The prevalence with which such medications are prescribed in older adults undergoing major surgery is not well described nor is their mediating relationship with delirium and dementia. We sought to determine the prevalence of high-risk medication use in major surgery patients and their relationship with the subsequent development of dementia.

METHODS

This was a retrospective cohort study which used data between January 2013 and December 2019, in a large midwestern health system, including sixteen hospitals. All patients over age 50 undergoing surgery requiring an inpatient stay were included. The primary exposure was the number of doses of anticholinergic medications delivered during the hospital stay. The primary outcome was a new diagnosis of Alzheimer's disease and related dementias at 1-y postsurgery. Regression methods and a mediation analysis were used to explore relationships between anticholinergic medication usage, delirium, and dementia.

RESULTS

There were 39,665 patients included, with a median age of 66. Most patients were exposed to anticholinergic medications (35,957/39,665; 91%), and 7588/39,665 (19.1%) patients received six or more doses during their hospital stay. Patients with at least six doses of these medications were more likely to be female, black, and with a lower American Society of Anesthesiologists class. Upon adjusted analysis, high doses of anticholinergic medications were associated with increased odds of dementia at 1 y relative to those with no exposure (odds ratio 2.7; 95% confidence interval 2.2-3.3). On mediation analysis, postoperative delirium mediated the effect of anticholinergic medications on dementia, explaining an estimated 57.6% of their association.

CONCLUSIONS

High doses of anticholinergic medications are common in major surgery patients and, in part via a mediating relationship with postoperative delirium, are associated with the development of dementia 1 y following surgery. Strategies to decrease the use of these medications and encourage the use of alternatives may improve long-term cognitive recovery.

Characterizing medical patients with delirium: A cohort study comparing ICD-10 codes and a validated chart review method

BACKGROUND

Delirium is a major cause of preventable mortality and morbidity in hospitalized adults, but accurately determining rates of delirium remains a challenge.

OBJECTIVE

To characterize and compare medical inpatients identified as having delirium using two common methods, administrative data and retrospective chart review.

METHODS

We conducted a retrospective study of 3881 randomly selected internal medicine hospital admissions from six acute care hospitals in Toronto and Mississauga, Ontario, Canada. Delirium status was determined using ICD-10-CA codes from hospital administrative data and through a previously validated chart review method. Baseline sociodemographic and clinical characteristics, processes of care and outcomes were compared across those without delirium in hospital and those with delirium as determined by administrative data and chart review.

RESULTS

Delirium was identified in 6.3% of admissions by ICD-10-CA codes compared to 25.7% by chart review. Using chart review as the reference standard, ICD-10-CA codes for delirium had sensitivity 24.1% (95%CI: 21.5-26.8%), specificity 99.8% (95%CI: 99.5-99.9%), positive predictive value 97.6% (95%CI: 94.6-98.9%), and negative predictive value 79.2% (95%CI: 78.6-79.7%). Age over 80, male gender, and Charlson comorbidity index greater than 2 were associated with misclassification of delirium. Inpatient mortality and median costs of care were greater in patients determined to have delirium by ICD-10-CA codes (5.8% greater mortality, 95% CI: 2.0-9.5 and $6824 greater cost, 95%CI: 4713-9264) and by chart review (11.9% greater mortality, 95%CI: 9.5-14.2% and $4967 greater cost, 95%CI: 4415-5701), compared to patients without delirium.

CONCLUSIONS

Administrative data are specific but highly insensitive, missing most cases of delirium in hospital. Mortality and costs of care were greater for both the delirium cases that were detected and missed by administrative data. Better methods of routinely measuring delirium in hospital are needed.

New Onset Geriatric Syndromes and One-year Outcomes Following Elective Gastrointestinal Cancer Surgery

OBJECTIVE

To assess whether older adults who develop geriatric syndromes following elective gastrointestinal surgery have poorer 1-year outcomes.

BACKGROUND

Within 10 years, 70% of all cancers will occur in older adults ≥65 years old. The rise in older adults requiring major surgery has brought attention to age-related complications termed geriatric syndromes. However, whether postoperative geriatric syndromes are associated with long-term outcomes is unclear.

METHODS

A population-based retrospective cohort study using the New York State Cancer Registry and the Statewide Planning and Research Cooperative System was performed including patients >55 years with pathologic stage I-III esophageal, gastric, pancreatic, colon, or rectal cancer who underwent elective resection between 2004 and 2018. Those aged 55 to 64 served as the reference group. The exposure of interest was a geriatric syndrome [fracture, fall, delirium, pressure ulcer, depression, malnutrition, failure to thrive, dehydration, or incontinence (urinary/fecal)] during the surgical admission. Patients with any geriatric syndrome within 1 year of surgery were excluded. Outcomes included incident geriatric syndrome, 1-year days alive and out of the hospital, and 1-year all-cause mortality.

RESULTS

In this study, 37,998 patients with a median age of 71 years without a prior geriatric syndrome were included. Of those 65 years or more, 6.4% developed a geriatric syndrome. Factors associated with an incident geriatric syndrome were age, alcohol/tobacco use, comorbidities, neoadjuvant therapy, ostomies, open surgery, and upper gastrointestinal cancers. An incident geriatric syndrome was associated with a 43% higher risk of 1-year mortality (hazard ratio, 1.43; 95% confidence interval, 1.27-1.60). For those aged 65+ discharged alive and not to hospice, a geriatric syndrome was associated with significantly fewer days alive and out of hospital (322 vs 346 days, P < 0.0001). There was an indirect relationship between the number of geriatric syndromes and 1-year mortality and days alive and out of the hospital after adjusting for surgical complications.

CONCLUSIONS

Given the increase in older adults requiring major surgical intervention, and the establishment of geriatric surgery accreditation programs, these data suggest that morbidity and mortality metrics should be adjusted to accommodate the independent relationship between geriatric syndromes and long-term outcomes.

Comparative safety of tramadol and other opioids following total hip and knee arthroplasty

BACKGROUND

Tramadol is increasingly used to treat acute postoperative pain among older adults following total hip and knee arthroplasty (THA/TKA). However, tramadol has a complex pharmacology and may be no safer than full opioid agonists. We compared the safety of tramadol, oxycodone, and hydrocodone among opioid-naïve older adults following elective THA/TKA.

METHODS

This retrospective cohort included Medicare Fee-for-Service beneficiaries ≥ 65 years with elective THA/TKA between January 1, 2010 and September 30, 2015, 12 months of continuous Parts A and B enrollment, 6 months of continuous Part D enrollment, and no opioid use in the 6 months prior to THA/TKA. Participants initiated single-opioid therapy with tramadol, oxycodone, or hydrocodone within 7 days of discharge from THA/TKA hospitalization, regardless of concurrently administered nonopioid analgesics. Outcomes of interest included all-cause hospitalizations or emergency department visits (serious adverse events (SAEs)) and a composite of 10 surgical- and opioid-related SAEs within 90-days of THA/TKA. The intention-to-treat (ITT) and per-protocol (PP) hazard ratios (HRs) for tramadol versus other opioids were estimated using inverse-probability-of-treatment-weighted pooled logistic regression models.

RESULTS

The study population included 2,697 tramadol, 11,407 oxycodone, and 14,665 hydrocodone initiators. Compared to oxycodone, tramadol increased the rate of all-cause SAEs in ITT analyses only (ITT HR 1.19, 95%CLs, 1.02, 1.41; PP HR 1.05, 95%CLs, 0.86, 1.29). Rates of composite SAEs were not significant across comparisons. Compared to hydrocodone, tramadol increased the rate of all-cause SAEs in the ITT and PP analyses (ITT HR 1.40, 95%CLs, 1.10, 1.76; PP HR 1.34, 95%CLs, 1.03, 1.75), but rates of composite SAEs were not significant across comparisons.

CONCLUSIONS

Postoperative tramadol was associated with increased rates of all-cause SAEs, but not composite SAEs, compared to oxycodone and hydrocodone. Tramadol does not appear to have a superior safety profile and should not be preferentially prescribed to opioid-naïve older adults following THA/TKA.

Association Between the Use of Midazolam During Cardiac Anesthesia and the Incidence of Postoperative Delirium: A Retrospective Cohort Study Using a Nationwide Database

OBJECTIVE

To evaluate the association between the intraoperative administration of midazolam and the incidence of postoperative delirium in patients undergoing cardiac surgery.

DESIGN

Retrospective observational cohort study.

SETTING

The Japanese Diagnosis Procedure Combination database.

PARTICIPANTS

Patients aged 65 years and older who underwent cardiovascular surgery (excluding transcatheter surgeries, multiple surgeries per admission, and preoperative delirium) between April 1, 2015, and October 31, 2019.

MEASUREMENTS AND MAIN RESULTS

Patients who received midazolam (midazolam group) were compared with those who did not receive midazolam (no midazolam group). The primary outcome was the incidence of postoperative delirium. The secondary outcomes were the incidence of postoperative nausea and vomiting, mortality, and duration of intensive care unit stay and hospitalization. Propensity scores were estimated using logistic regression based on the covariates. The outcomes were compared using stabilized inverse probability of treatment-weighting analyses. Among the 16,185 patients analyzed, 10,633 (65.7%) received midazolam. No significant differences were observed in the incidences of postoperative delirium (odds ratio [OR] 0.95; 95% CI 0.87-1.03; p = 0.21) and hospital mortality (OR 0.92; 95% CI 0.76-1.11; p = 0.39) between the groups; however, the midazolam group had slightly longer durations of intensive care unit stay (3.5 [3.5-3.6] v 3.3 [3.3-3.4] days, p < 0.001) and hospitalization (31.5 [31.1-31.9] v 29.4 [28.8-29.9] days, p < 0.001), and slightly lower incidences of postoperative nausea and vomiting (OR 0.92; 95% CI 0.85-0.99; p = 0.03). The sensitivity analyses supported these results.

CONCLUSIONS

Intraoperative administration of midazolam may not induce postoperative delirium in patients undergoing cardiac surgery.

Clinical Prediction Models for Hospital-Induced Delirium Using Structured and Unstructured Electronic Health Record Data: Protocol for a Development and Validation Study

BACKGROUND

Hospital-induced delirium is one of the most common and costly iatrogenic conditions, and its incidence is predicted to increase as the population of the United States ages. An academic and clinical interdisciplinary systems approach is needed to reduce the frequency and impact of hospital-induced delirium.

OBJECTIVE

The long-term goal of our research is to enhance the safety of hospitalized older adults by reducing iatrogenic conditions through an effective learning health system. In this study, we will develop models for predicting hospital-induced delirium. In order to accomplish this objective, we will create a computable phenotype for our outcome (hospital-induced delirium), design an expert-based traditional logistic regression model, leverage machine learning techniques to generate a model using structured data, and use machine learning and natural language processing to produce an integrated model with components from both structured data and text data.

METHODS

This study will explore text-based data, such as nursing notes, to improve the predictive capability of prognostic models for hospital-induced delirium. By using supervised and unsupervised text mining in addition to structured data, we will examine multiple types of information in electronic health record data to predict medical-surgical patient risk of developing delirium. Development and validation will be compliant to the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement.

RESULTS

Work on this project will take place through March 2024. For this study, we will use data from approximately 332,230 encounters that occurred between January 2012 to May 2021. Findings from this project will be disseminated at scientific conferences and in peer-reviewed journals.

CONCLUSIONS

Success in this study will yield a durable, high-performing research-data infrastructure that will process, extract, and analyze clinical text data in near real time. This model has the potential to be integrated into the electronic health record and provide point-of-care decision support to prevent harm and improve quality of care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48521.

Comparative safety of antimuscarinics versus mirabegron for overactive bladder in Parkinson disease

BACKGROUND

Overactive bladder (OAB) is a common non-motor symptom of Parkinson disease (PD), often treated with antimuscarinics or beta-3 agonists. There is lack of evidence to guide OAB management in PD.

OBJECTIVES

To assess the comparative safety of antimuscarinics versus beta-3 agonists for OAB treatment in PD.

METHODS

We employed a new-user, active-comparator cohort study design. We included Medicare beneficiaries age ≥65 years with PD who were new users of either antimuscarinic or beta-3 agonist. The primary outcome was any acute care encounter (i.e., non-elective hospitalization or emergency department visit) within 90 days of OAB drug initiation. The main secondary outcome was a composite measure of acute care encounters for anticholinergic related adverse events (AEs). Matching on high-dimensional propensity score (hdPS) was used to address potential confounding. We used Cox proportional hazards models to examine the association between OAB drug category and outcomes. We repeated analyses for 30- and 180-day follow-up periods.

RESULTS

We identified 27,091 individuals meeting inclusion criteria (mean age: 77.8 years). After hdPS matching, antimuscarinic users had increased risks for any acute care encounter (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.12-1.37) and encounters for anticholinergic related AEs (HR 1.18, 95% CI 1.04-1.34) compared to beta-3 agonist users. Similar associations were observed for sensitivity analyses.

CONCLUSIONS

Among persons with PD, anticholinergic initiation was associated with a higher risk of acute care encounters compared with beta-3 agonist initiation. The long-term safety of anticholinergic vs. beta-3 agonist therapy in the PD population should be evaluated in a prospective study.

Initiation of oral anticoagulation in US older adults newly diagnosed with atrial fibrillation during hospitalization

BACKGROUND

Atrial fibrillation is a common cause of stroke among older adults and is often first detected during hospitalization, given frequent use of cardiac telemetry.

METHODS

In a 20% national sample of Medicare fee-for-service beneficiaries, we identified patients aged 65-or-older newly diagnosed with atrial fibrillation while hospitalized in 2016. Our primary outcome was an oral anticoagulant claim within 7-days of discharge. Multivariable logistic regression analyses assessed relationships between anticoagulation initiation and thromboembolic and bleeding risk scores while controlling for demographics, frailty, comorbidities, and hospitalization characteristics.

RESULTS

Among 38,379 older adults newly diagnosed with atrial fibrillation while hospitalized (mean age 78.2 [SD 8.4]; 51.8% female; 83.3% white), 36,633 (95.4%) had an indication for anticoagulation and 24.6% (9011) of those initiated an oral anticoagulant following discharge. Higher CHA2 DS2 -VASc score was associated with a small increase in oral anticoagulant initiation (predicted probability 20.5% [95% CI, 18.7%-22.3%] for scores <2 and 24.9% [CI, 24.4%-25.4%] for ≥4). Elevated HAS-BLED score was associated with a small decrease in probability of anticoagulant initiation (25.4% [CI, 24.4%-26.4%] for score <2 and 23.1% [CI, 22.5%-23.8%] for ≥3). Frailty was associated with decreased likelihood of oral anticoagulant initiation (24.7% [CI, 23.2%-26.2%] for non-frail and 18.1% [CI, 16.6%-19.6%] for moderately-severely frail). Anticoagulant initiation varied by primary reason for hospitalization, with predicted probability highest among patients with a primary diagnosis of atrial fibrillation (46.1% [CI, 45.0%-47.3%]) and lowest among those with non-cardiovascular conditions (13.8% [CI, 13.3%-14.3%]) and bleeds (3.6% [CI, 2.4%-4.8%]).

CONCLUSIONS

Oral anticoagulant initiation is uncommon among older adults newly diagnosed with atrial fibrillation during hospitalization, even among patients hospitalized primarily for atrial fibrillation and patients with high thromboembolic risk. Clinicians should discuss risks and benefits of oral anticoagulants with all inpatients found to have atrial fibrillation.

Delirium among people aging with and without HIV: Role of alcohol and Neurocognitively active medications

BACKGROUND

People aging with and without HIV (PWH and PWoH) want to avoid neurocognitive dysfunction, especially delirium. Continued use of alcohol in conjunction with neurocognitively active medications (NCAMs) may be a largely underappreciated cause, especially for PWH who experience polypharmacy a decade earlier than PWoH. We compare absolute and relative risk of delirium among PWH and PWoH by age, level of alcohol use, and exposure to NCAMs.

METHODS

Using the VACS cohort, we compare absolute and relative risk of inpatient delirium among PWH and PWoH by age, level of alcohol use, and exposure to NCAMs between 2007 and 2019. We matched each case based on age, race/ethnicity, sex, HIV, baseline year, and observation time with up to 5 controls. The case/control date was defined as date of admission for cases and the date corresponding to the same length of time on study for controls. Level of alcohol use was defined using Alcohol Use Disorder Identification Test-Consumption (AUDIT-C). Medication exposure was measured from 45 to 3 days prior to index date; medications were classified as anticholinergic NCAM, non-anticholinergic NCAM, or non NCAM and counts generated. We used logistic regression to determine odds ratios (ORs) for delirium associated with medication counts stratified by HIV status and adjusted for demographics, severity of illness, and related diagnoses.

RESULTS

PWH experienced a higher incidence of delirium (5.6, [95% CI 5.3-5.9/1000 PY]) than PWoH (5.0, [95% CI 4.8-5.1/1000 PY]). In multivariable analysis, anticholinergic and non-anticholinergic NCAM counts and level of alcohol use demonstrated strong independent dose-response associations with delirium.

CONCLUSIONS

Decreasing alcohol use and limiting the use of neurocognitively active medications may help decrease excess rates of delirium, especially among PWH.

Adverse events with quetiapine and clarithromycin coprescription: A population-based retrospective cohort study

Background and Aims

Quetiapine is an atypical antipsychotic predominantly metabolized by the cytochrome P450 3A4 (CYP3A4) enzyme. We studied the risk of adverse events following coprescription of clarithromycin (a strong CYP3A4 inhibitor) versus azithromycin (not a CYP3A4 inhibitor) in quetiapine users.

Materials and Methods

This was a population-based retrospective cohort study from 2004 to 2020 in Ontario, Canada in adult quetiapine users newly co-prescribed clarithromycin (n = 16,909) or azithromycin (n = 25,267). The primary outcome was the composite of hospital encounters with encephalopathy (defined as a diagnosis of delirium, disorientation, transient alteration of awareness, transient ischemic attack, or unspecified dementia), a fall, or a fracture within 30 days of new coprescription. Secondary outcomes were individual components of the composite outcome, hospital encounter with computed tomography (CT) head scan, and all-cause mortality.

Results

Coprescription of clarithromycin versus azithromycin with quetiapine was associated with a higher risk of the primary composite outcome (365 of 16,909 clarithromycin users [2.2%] vs. 309 of 16,929 azithromycin users [1.8%]; absolute risk increase, 0.34% [95% confidence interval, CI, 0.04-0.63]; relative risk [RR], 1.19 [95% CI, 1.02-1.38]). This was primarily driven by an increase in fragility fractures (78 of 16,909 clarithromycin users [0.5%] vs. 45 of 16,923 azithromycin users [0.3%]; absolute risk increase, 0.20% [95% CI, 0.07-0.32]; RR, 1.74 [95% CI, 1.21-2.52]). Hospital encounters with a CT head scan were higher in clarithromycin users (220 of 16,909 [1.3%] vs. 175 of 16,923 azithromycin users [1.0%]; absolute risk increase, 0.27% [95% CI, 0.04-0.50]; RR, 1.26 [95% CI, 1.04-1.54]), but there was no difference in hospital encounters with encephalopathy, falls, or all-cause mortality between macrolide groups.

Conclusion

Among adults taking quetiapine, concurrent use of clarithromycin compared with azithromycin was associated with a small but statistically greater 30-day risk of a hospital encounter for encephalopathy, falls, or fracture, which was predominantly related to a higher rate of fragility fractures.

Delirium in ventilated patients receiving fentanyl and morphine for Analgosedation: Findings from the ANALGESIC trial

PURPOSE

The differential effect of fentanyl vs. morphine analgosedation on the development of hospital inpatient delirium in patients receiving mechanical ventilation is unknown. We aimed to compare the incidence of coding for delirium and antipsychotic medication use in patients treated with fentanyl vs. morphine in the ANALGESIC trial.

MATERIALS AND METHODS

We obtained data from a cluster randomized, cluster crossover trial of fentanyl vs. morphine for analgosedation on antipsychotic use and coding diagnosis of delirium and compared these outcomes according to treatment allocation. We assessed the relationship between opioid choice and dose, hospital inpatient delirium, and outcomes.

RESULTS

Among 681 patients enrolled in the ANALGESIC trial, 160/344 (46.5%) in the fentanyl group vs. 132/337 (39.1%) in the morphine group (absolute difference 7.34% [95% CI -0.9 to 14.78]; RR: 1.19 [95%CI 1.00 to 1.41]; p = 0.053) developed hospital inpatient delirium. Antipsychotic use was linearly related to opioid dose. Antipsychotic use was not associated with increased mortality.

CONCLUSIONS

Fentanyl is associated with a higher incidence of hospital inpatient delirium when used for analgosedation compared with morphine, and the dose of opioid is linearly related to the need for antipsychotic medication administration. The role of analgosedation in promoting delirium requires further investigation.

Baclofen and the Risk of Encephalopathy: A Real-World, Active-Comparator Cohort Study

OBJECTIVE

To quantify the risk of encephalopathy associated with oral baclofen compared with other muscle relaxants-tizanidine or cyclobenzaprine.

PATIENTS AND METHODS

We conducted a new-user, active-comparator study of 2 pairwise cohorts using tertiary health system data from Geisinger Health in Pennsylvania (January 1, 2005, through December 31, 2018). Adults (aged ≥18 years) newly treated with baclofen or tizanidine were included in cohort 1. Adults newly treated with baclofen or cyclobenzaprine were included in cohort 2. Propensity score-based inverse probability of treatment weighting (IPTW) was used to balance the respective cohorts on 45 patient characteristics. Fine-Gray competing risk regression was used to estimate the risk of encephalopathy.

RESULTS

Cohort 1 included 16,192 new baclofen users and 9782 new tizanidine users. The 30-day risk of encephalopathy was higher in patients treated with baclofen vs tizanidine (IPTW incidence rate, 64.7 vs 28.3 per 1000 person-years) with an IPTW subdistribution hazard ratio (SHR) of 2.29 (95% CI, 1.43 to 3.67). This risk persisted through 1 year (SHR, 1.32 [95% CI, 1.07 to 1.64]). Similarly in cohort 2, baclofen vs cyclobenzaprine was associated with a greater risk of encephalopathy at 30 days (SHR, 2.35 [95% CI, 1.59 to 3.48]) that persisted through the first year of treatment (SHR, 1.94 [95% CI, 1.56 to 2.40]).

CONCLUSION

The risk of encephalopathy was greater with baclofen vs tizanidine or cyclobenzaprine use. The elevated risk was apparent as early as 30 days and persisted through the first year of treatment. Our findings from routine care settings may inform shared treatment decisions between patients and prescribers.

New psychotropic medication use among Medicare beneficiaries with dementia after hospital discharge

BACKGROUND

Hospitalizations among people with dementia (PWD) may precipitate behavioral changes, leading to the psychotropic medication use despite adverse outcomes and limited efficacy. We sought to determine the incidence of new psychotropic medication use among community-dwelling PWD after hospital discharge and, among new users, the proportion with prolonged use.

METHODS

This was a retrospective cohort study using a 20% random sample of Medicare claims in 2017, including hospitalized PWD with traditional and Part D Medicare who were 68 years or older. The primary outcome was incident prescribing at discharge of psychotropics including antipsychotics, sedative-hypnotics, antiepileptics, and antidepressants. This was defined as new prescription fills (i.e., from classes not used in 180 days preadmission) within 7 days of hospital or skilled nursing facility discharge. Prolonged use was defined as the proportion of new users who continued to fill newly prescribed medications beyond 90 days of discharge.

RESULTS

The cohort included 117,022 hospitalized PWD with a mean age of 81 years; 63% were female. Preadmission, 63% were using at least 1 psychotropic medication; 10% were using medications from ≥3 psychotropic classes. These included antidepressants (44% preadmission), antiepileptics (29%), sedative-hypnotics (21%), and antipsychotics (11%). The proportion of PWD discharged from the hospital with new psychotropics ranged from 1.9% (antipsychotics) to 2.9% (antiepileptics); 6.6% had at least one new class started. Among new users, prolonged use ranged from 36% (sedative-hypnotics) to 63% (antidepressants); across drug classes, prolonged use occurred in 51%. Predictors of newly initiated psychotropics included length of stay (≥median vs.

CONCLUSIONS

Hospitalized PWD have a high prevalence of preadmission psychotropic medication use; against this baseline, discharge from the hospital with new psychotropics is relatively uncommon. Nevertheless, prolonged use of newly initiated psychotropics occurs in a substantial proportion of this population.

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Key Words

• dementia
• hospitalization
• prescribing
• psychotropics

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MESH Headings

• Humans
• Female
• Aged
• United States
• Aged, 80 and over
• Male
• Patient Discharge
• Retrospective Studies
• Anticonvulsants/therapeutic use
• Dementia/drug therapy
• Medicare
• Psychotropic Drugs/therapeutic use
• Antipsychotic Agents/therapeutic use
• Antidepressive Agents/therapeutic use
• Hospitals
• Hypnotics and Sedatives/therapeutic use

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Grants

• K12 HS026383 AHRQ HHS
• L30 AG074160 NIA NIH HHS
• R24 AG064025 NIA NIH HHS
• K24 AG049057 NIA NIH HHS
• R35 AG071916 NIA NIH HHS
• R03 AG064373 NIA NIH HHS
• T32 AG000212 NIA NIH HHS
• P01 AG066605 NIA NIH HHS
• K01 AG073532 NIA NIH HHS
• P30 AG044281 NIA NIH HHS
• R03 AG078804 NIA NIH HHS

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Affiliation(s)

Matthew E Growdon Division of Geriatrics, University of California, San Francisco, California, USA Geriatrics, Palliative, and Extended Care Service Line, San Francisco VA Medical Center, San Francisco, California, USA
Siqi Gan Division of Geriatrics, University of California, San Francisco, California, USA Northern California Institute for Research and Education, San Francisco, California, USA
Kristine Yaffe Mental Health, San Francisco VA Medical Center, San Francisco, California, USA Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA Departments of Neurology and Psychiatry, University of California, San Francisco, California, USA
Alexandra K Lee Division of Geriatrics, University of California, San Francisco, California, USA Geriatrics, Palliative, and Extended Care Service Line, San Francisco VA Medical Center, San Francisco, California, USA
Timothy S Anderson Division of General Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
Ulrike Muench Department of Social and Behavioral Sciences, School of Nursing, University of California, San Francisco, California, USA
W John Boscardin Division of Geriatrics, University of California, San Francisco, California, USA Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
Michael A Steinman Division of Geriatrics, University of California, San Francisco, California, USA Geriatrics, Palliative, and Extended Care Service Line, San Francisco VA Medical Center, San Francisco, California, USA

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Post-discharge use of antipsychotics in patients with hospital-acquired delirium and associated risk of mortality - A population-based nested case-control study

OBJECTIVE

To evaluate post-discharge use of antipsychotics in patients with incident hospital-acquired delirium and the associated risk of mortality.

METHODS

We conducted a nested case-control study for patients newly diagnosed with hospital-acquired delirium and subsequently discharged from hospital using Taiwan's National Health Insurance Database (NHID) from 2011 to 2018.

RESULTS

The use of antipsychotics after discharge did not increase the risk of mortality (adjusted OR: 1·03; 95% CI: 0·98-1·09).

CONCLUSIONS

The findings suggested that using antipsychotics after discharge in patients with hospital-acquired delirium may not increase the risk of mortality.

The Burden of Postoperative Delirium After Shoulder Arthroplasty and Modifiable Pharmacological Perioperative Risk Factors: A Retrospective Nationwide Cohort Study

Background: Increasing demand for shoulder arthroplasty and an aging population may increase the rate of complications associated with advanced age such as postoperative delirium, but little is known on its burden in this cohort. Purpose: We sought to answer the following questions: (1) What is the epidemiology of postoperative delirium after shoulder arthroplasty? (2) What modifiable risk factors can be identified for postoperative delirium after shoulder arthroplasty? (3) Do risk factors differ in those younger than and in those older than 70 years of age? Methods: In a retrospective nationwide cohort study, we extracted data from the Premier Healthcare database on inpatient total and reverse shoulder arthroplasties from 2006 to 2016. The primary outcome was postoperative delirium; modifiable risk factors of interest were perioperative opioid use (high, medium, or low), peripheral nerve block use, and perioperative prescription medications. Mixed-effects models assessed associations between risk factors and postoperative delirium. Odds ratios and confidence intervals are reported. We applied a cutoff of 70 years of age because it was the median age of the cohort, as well as the age at which we observed that delirium prevalence increased. Results: A total of 92,429 total and reverse shoulder arthroplasties were identified (age range: 14-89 years). Overall delirium prevalence was 3.1% (n = 2909). Age-specific prevalence of postoperative delirium was lower in patients aged 50 to 70 years and higher in those aged 70 years and older, up to 8% among those older than 88 years. After adjusting for relevant covariates, only long-acting and combined short-acting and long-acting benzodiazepines (compared with no benzodiazepines) were associated with increased odds of postoperative delirium. Corticosteroids were associated with decreased odds of postoperative delirium. Conclusion: Our retrospective cohort study demonstrated that benzodiazepine use and older patient age were significantly associated with postoperative delirium in shoulder arthroplasty patients. The relationship between benzodiazepine use and delirium was particularly notable among those 70 years of age and older. Further investigation is indicated, given the known adverse effects of benzodiazepines in older adults and our findings of higher than expected use of these medications in this surgical cohort.

Identifying encephalopathy in patients admitted to an intensive care unit: Going beyond structured information using natural language processing

Background

Encephalopathy is a severe co-morbid condition in critically ill patients that includes different clinical constellation of neurological symptoms. However, even for the most recognised form, delirium, this medical condition is rarely recorded in structured fields of electronic health records precluding large and unbiased retrospective studies. We aimed to identify patients with encephalopathy using a machine learning-based approach over clinical notes in electronic health records.

Methods

We used a list of ICD-9 codes and clinical concepts related to encephalopathy to define a cohort of patients from the MIMIC-III dataset. Clinical notes were annotated with MedCAT and vectorized with a bag-of-word approach or word embedding using clinical concepts normalised to standard nomenclatures as features. Machine learning algorithms (support vector machines and random forest) trained with clinical notes from patients who had a diagnosis of encephalopathy (defined by ICD-9 codes) were used to classify patients with clinical concepts related to encephalopathy in their clinical notes but without any ICD-9 relevant code. A random selection of 50 patients were reviewed by a clinical expert for model validation.

Results

Among 46,520 different patients, 7.5% had encephalopathy related ICD-9 codes in all their admissions (group 1, definite encephalopathy), 45% clinical concepts related to encephalopathy only in their clinical notes (group 2, possible encephalopathy) and 38% did not have encephalopathy related concepts neither in structured nor in clinical notes (group 3, non-encephalopathy). Length of stay, mortality rate or number of co-morbid conditions were higher in groups 1 and 2 compared to group 3. The best model to classify patients from group 2 as patients with encephalopathy (SVM using embeddings) had F1 of 85% and predicted 31% patients from group 2 as having encephalopathy with a probability >90%. Validation on new cases found a precision ranging from 92% to 98% depending on the criteria considered.

Conclusions

Natural language processing techniques can leverage relevant clinical information that might help to identify patients with under-recognised clinical disorders such as encephalopathy. In the MIMIC dataset, this approach identifies with high probability thousands of patients that did not have a formal diagnosis in the structured information of the EHR.

Incremental medical cost of delirium in elderly patients with cognitive impairment: analysis of a nationwide administrative database in Japan

OBJECTIVES

Delirium is a neuropsychiatric disorder that commonly occurs in elderly patients with cognitive impairment. The economic burden of delirium in Japan has not been well characterised. In this study, we assessed incremental medical costs of delirium in hospitalised elderly Japanese patients with cognitive impairment.

DESIGN

Retrospective, cross-sectional, observational study.

SETTING

Administrative data collected from acute care hospitals in Japan between April 2012 and September 2020.

PARTICIPANTS

Hospitalised patients ≥65 years old with cognitive impairment were categorised into groups-with and without delirium. Delirium was identified using a delirium identification algorithm based on the International Classification of Diseases 10^th Revision codes or antipsychotic prescriptions.

OUTCOME MEASURES

Total medical costs during hospitalisation were compared between the groups using a generalised linear model.

RESULTS

The study identified 297 600 hospitalised patients ≥65 years of age with cognitive impairment: 39 836 had delirium and 257 764 did not. Patient characteristics such as age, sex, inpatient department and comorbidities were similar between groups. Mean (SD) unadjusted total medical cost during hospitalisation was 979 907.7 (871 366.4) yen for patients with delirium and 816 137.0 (794 745.9) yen for patients without delirium. Adjusted total medical cost was significantly greater for patients with delirium compared with those without delirium (cost ratio=1.09, 95% CI: 1.09 to 1.10; p<0.001). Subgroup analyses revealed significantly higher total medical costs for patients with delirium compared with those without delirium in most subgroups except patients with hemiplegia or paraplegia.

CONCLUSIONS

Medical costs during hospitalisation were significantly higher for patients with delirium compared with those without delirium in elderly Japanese patients with cognitive impairment, regardless of patient subgroups such as age, sex, intensive care unit admission and most comorbidities. These findings suggest that delirium prevention strategies are critical to reducing the economic burden as well as psychological/physiological burden in cognitively impaired elderly patients in Japan.

Association of Diagnosed Dementia with Post-discharge Mortality and Readmission Among Hospitalized Medicare Beneficiaries

BACKGROUND

Patients with dementia are frequently hospitalized and may face barriers in post-discharge care.

OBJECTIVE

To determine whether patients with dementia have an increased risk of adverse outcomes following discharge.

DESIGN

Retrospective cohort study.

SUBJECTS

Medicare beneficiaries hospitalized in 2016.

MAIN MEASURES

Co-primary outcomes were mortality and readmission within 30 days of discharge. Multivariable logistic regression models were estimated to assess the risk of each outcome for patients with and without dementia accounting for demographics, comorbidities, frailty, hospitalization factors, and disposition.

KEY RESULTS

The cohort included 1,089,109 hospitalizations of which 211,698 (19.3%) were of patients with diagnosed dementia (median (IQR) age 83 (76-89); 61.5% female) and 886,411 were of patients without dementia (median (IQR) age 76 (79-83); 55.0% female). At 30 days following discharge, 5.7% of patients with dementia had died compared to 3.1% of patients without dementia (adjusted odds ratio (aOR) 1.21; 95% CI 1.17 to 1.24). At 30 days following discharge, 17.7% of patients with dementia had been readmitted compared to 13.1% of patients without dementia (aOR 1.02; CI 1.002 to 1.04). Dementia was associated with an increased odds of readmission among patients discharged to the community (aOR 1.07, CI 1.05 to 1.09) but a decreased odds of readmission among patients discharge to nursing facilities (aOR 0.93, CI 0.90 to 0.95). Patients with dementia who were discharged to the community were more likely to be readmitted than those discharged to nursing facilities (18.9% vs 16.0%), and, when readmitted, were more likely to die during the readmission (20.7% vs 4.4%).

CONCLUSIONS

Diagnosed dementia was associated with a substantially increased risk of mortality and a modestly increased risk of readmission within 30 days of discharge. Patients with dementia discharged to the community had particularly elevated risk of adverse outcomes indicating possible gaps in post-discharge services and caregiver support.

Identifying Medicare Beneficiaries With Delirium

BACKGROUND

Each year, thousands of older adults develop delirium, a serious, preventable condition. At present, there is no well-validated method to identify patients with delirium when using Medicare claims data or other large datasets. We developed and assessed the performance of classification algorithms based on longitudinal Medicare administrative data that included International Classification of Diseases, 10th Edition diagnostic codes.

METHODS

Using a linked electronic health record (EHR)-Medicare claims dataset, 2 neurologists and 2 psychiatrists performed a standardized review of EHR records between 2016 and 2018 for a stratified random sample of 1002 patients among 40,690 eligible subjects. Reviewers adjudicated delirium status (reference standard) during this 3-year window using a structured protocol. We calculated the probability that each patient had delirium as a function of classification algorithms based on longitudinal Medicare claims data. We compared the performance of various algorithms against the reference standard, computing calibration-in-the-large, calibration slope, and the area-under-receiver-operating-curve using 10-fold cross-validation (CV).

RESULTS

Beneficiaries had a mean age of 75 years, were predominately female (59%), and non-Hispanic Whites (93%); a review of the EHR indicated that 6% of patients had delirium during the 3 years. Although several classification algorithms performed well, a relatively simple model containing counts of delirium-related diagnoses combined with patient age, dementia status, and receipt of antipsychotic medications had the best overall performance [CV- calibration-in-the-large <0.001, CV-slope 0.94, and CV-area under the receiver operating characteristic curve (0.88 95% confidence interval: 0.84-0.91)].

CONCLUSIONS

A delirium classification model using Medicare administrative data and International Classification of Diseases, 10th Edition diagnosis codes can identify beneficiaries with delirium in large datasets.

New onset delirium prediction using machine learning and long short-term memory (LSTM) in electronic health record

OBJECTIVE

To develop and test an accurate deep learning model for predicting new onset delirium in hospitalized adult patients.

METHODS

Using electronic health record (EHR) data extracted from a large academic medical center, we developed a model combining long short-term memory (LSTM) and machine learning to predict new onset delirium and compared its performance with machine-learning-only models (logistic regression, random forest, support vector machine, neural network, and LightGBM). The labels of models were confusion assessment method (CAM) assessments. We evaluated models on a hold-out dataset. We calculated Shapley additive explanations (SHAP) measures to gauge the feature impact on the model.

RESULTS

A total of 331 489 CAM assessments with 896 features from 34 035 patients were included. The LightGBM model achieved the best performance (AUC 0.927 [0.924, 0.929] and F1 0.626 [0.618, 0.634]) among the machine learning models. When combined with the LSTM model, the final model's performance improved significantly (P = .001) with AUC 0.952 [0.950, 0.955] and F1 0.759 [0.755, 0.765]. The precision value of the combined model improved from 0.497 to 0.751 with a fixed recall of 0.8. Using the mean absolute SHAP values, we identified the top 20 features, including age, heart rate, Richmond Agitation-Sedation Scale score, Morse fall risk score, pulse, respiratory rate, and level of care.

CONCLUSION

Leveraging LSTM to capture temporal trends and combining it with the LightGBM model can significantly improve the prediction of new onset delirium, providing an algorithmic basis for the subsequent development of clinical decision support tools for proactive delirium interventions.

Demographic and clinical characteristics of patients with delirium: analysis of a nationwide Japanese medical database

OBJECTIVES

Delirium commonly occurs during hospitalisation and is associated with increased mortality, especially in elderly patients. This study aimed to determine the demographic and clinical characteristics of patients with delirium in the Japanese real-world clinical setting using a nationwide database comprising claims and discharge abstract data.

DESIGN

This was an observational, cross-sectional, retrospective study in hospitalised patients with an incident delirium identified by a diagnosis based on International Classification of Diseases, 10th Revision codes or initiating antipsychotics recommended for delirium treatment in Japan during their hospitalisation.

SETTING

Patients from the Medical Data Vision database including more than 400 acute care hospitals in Japan were evaluated from admission to discharge.

PARTICIPANTS

Of the 32 910 227 patients who were included in the database between April 2012 and September 2020, a total of 145 219 patients met the criteria for delirium.

PRIMARY AND SECONDARY OUTCOME MEASURES

Demographic and baseline characteristics, comorbidities, clinical profiles and pharmacological treatments were evaluated in patients with delirium.

RESULTS

The mean (SD) patient age was 76.5 (13.8) years. More than half of the patients (n=82 159; 56.6%) were male. The most frequent comorbidities were circulatory system diseases, observed in 81 954 (56.4%) patients. Potentially inappropriate medications (PIMs) with risk of delirium including benzodiazepines and opioids were prescribed to 76 798 (52.9%) patients. Approximately three-fourths of these patients (56 949; 74.2%) were prescribed ≥4 PIMs. The most prescribed treatment for delirium was injectable haloperidol (n=82 490; 56.8%). Mean (SD) length of hospitalisation was 16.0 (12.1) days.

CONCLUSIONS

The study results provide comprehensive details of the clinical characteristics of patients with delirium and treatment patterns with antipsychotics in the Japanese acute care setting. In this patient population, the prescription rate of injectable haloperidol and PIMs was high, suggesting the need for improved understanding among healthcare providers about the appropriate management of delirium, which may benefit patients.

Drug Utilization Evaluation (DUE) of vancomycin: A cross-sectional study

Objective

Evaluating the use of antibiotics leads to identifying drug problems, preventing antibiotic resistance, and controlling the cost of medication. The aim of this study was to Drug Utilization Evaluation (DUE) of vancomycin.

Methods

This study was a descriptive retrospective cross-sectional study. Sampling method was the census. The information was collected through a checklist and referring to patients' files.

Results

170 children and 120 adults who received vancomycin were studied. The dose of vancomycin in the studied adults was 40.6% and 61% was in accordance with the Uptodate guideline. Also, the duration of treatment in the studied children was 10.6% and 15.3% according to the Uptodate guideline and in adults 30%, 39.2% was in accordance with the Uptodate guideline. Also, the indication for vancomycin in children was 14.1% and 18.8% in accordance with the Uptodate guideline, and in adults 40% and 52.5% was in accordance with the Uptodate guideline. The highest initial diagnosis in children was RDS 54.1%, seizure 9.4%, jaundice 9.4% and pneumonia 8.2%, and in adults 30% CRF and 11.7% catheter. In children, the most common complications were related to shortness of breath 41.2%, fever 18.8% and jaundice 11.8%, and in adults were related to fever 32.5%, lethargy 26.7% and shortness of breath 20%, respectively.

Conclusion

It is recommended to improve the administration and rational use of antibiotics and prevent the occurrence of microbial resistance, to follow the treatment patterns based on international standards in hospitals.

•

Evaluating the use of antibiotics leads to identifying drug problems.

•

Preventing antibiotic resistance, and controlling the cost of medication.

•

It is recommended to improve the administration and rational use of antibiotics and prevent.

•

DUE is a practical and continuous method, which evaluates the quality and economics of drug use.

•

This type of study be carried out with a larger sample size and in different populations.

An association between cancer type and delirium incidence in Japanese elderly patients: A retrospective longitudinal study

OBJECTIVE

There is not a known elevated prevalence of delirium in older adult cancer patients. However, it is unknown if the incidence of delirium varies by cancer type among older adult patients. Therefore, this study aimed to examine the association between the incidence of delirium and cancer type among older adult patients using a Japanese hospital-based administrative claims database.

METHODS

A total of 76,868 patients over 65 years of age or older, first diagnosed with cancer on an initial date of hospitalization between April 2008 and December 2019, were included in this retrospective longitudinal study. Delirium was defined by the World Health Organization's International Statistical Classification of Diseases and Related Health Problems (ICD-10) codes or antipsychotic medication use. Cox proportional hazard models were performed to estimate the risk of delirium incidence according to 22 cancer types during the one-year hospitalization period.

RESULTS

The incidence rates of delirium were 17.1% for men and 15.3% for women. Compared to gastric cancer, the risk of delirium was significantly higher for pancreatic cancer (HR: 1.26, 95% CI: 1.11-1.42 for men; HR: 1.27, 95% CI: 1.11-1.45 for women), leukemia (HR: 1.24, 95% CI: 1.09-1.41 for men; HR: 1.20, 95% CI: 1.03-1.41 for women), and oropharyngeal cancer (HR: 1.30, 95% CI: 1.10-1.54 for men; HR: 1.32; 95% CI: 1.02-1.72 for women) after adjusting for age, initial hospitalization year, antipsychotic medications, and surgery.

CONCLUSIONS

As compared to gastric cancer, patients with pancreatic cancer, leukemia, oropharyngeal cancer were found to have a higher risk of developing delirium. Our study findings suggested that the risk of delirium incidence may vary by cancer type.

The association of frailty with clinical and economic outcomes among hospitalized older adults with hip fracture surgery

Frailty is a common condition among older adults with hip fracture. In our study analyzing National Inpatient Sample data, frailty was found to be associated with up to six times increase in in-patient mortality, 55% increased length of hospital stay, and 29% increase in hospital cost.

INTRODUCTION

Hip fracture is a significant public health issue posing adverse health outcomes and substantial economic burden to patients and society. Frailty is a prevalent geriatric condition associated with poor clinical outcome among older adults. The association between hip fracture and frailty on both clinical and economic outcomes at the national level has not been estimated. We aimed to determine the association between frailty and in-hospital mortality, length of hospital stay (LOS), and total hospital cost among older patients aged ≥ 65 years who underwent surgery for hip fracture.

METHODS

We did an analysis of administrative data using the National Inpatient Sample (NIS) data from 2016 and 2017. Our analysis included data on 29,735 hospitalizations. We first conducted a descriptive analysis of the patient characteristics (demographics and clinical) and hospital-related factors. Three multivariable regression analysis models were then used to determine independent associations between frailty and in-hospital mortality, LOS, and total hospital cost. All three models were adjusted for patients' demographic and clinical characteristics and hospital-related factors.

RESULTS

Moderate and high frailty risk were associated with higher odds of death (OR = 2.94 and 95% CI 1.91-4.51 and OR = 5.99 and 95% CI 3.79-9.47), increased LOS (17% and 55%, p < 0.0001), and higher total hospital cost (7% and 29%, p < 0.0001) respectively compared to low frailty risk.

CONCLUSION

Frailty was associated with mortality, LOS, and hospital cost after adjusting for patient demographic, clinical, and hospital-related factors. Further research is needed to explore what pre-surgical measures can be assessed to mitigate in-hospital mortality and hospital cost in frail older patients hospitalized for hip fracture surgery.

Demand Ischemia as a Predictor of Mortality in Older Patients With Delirium

Introduction

The impact of demand ischemia on clinical outcomes in patients with delirium remains largely unexplored. This study aims to evaluate the effects of demand ischemia in older patients with delirium on in-hospital mortality and length of stay (LOS) using the largest US inpatient care database, National Inpatient Sample (NIS).

Methods

We obtained data from the year 2010 to 2014 National Inpatient Sample (NIS). We used the International Classification of Diseases-Ninth Edition-Clinical Modification (ICD-9-CM) diagnosis codes to identify all the records with a primary or secondary diagnosis of delirium with or without demand ischemia and other clinical characteristics. We then compared in-hospital mortality and length of stay (LOS) in patients with and without demand ischemia.

Results

We analyzed 232,137 records. Patients with demand ischemia had higher overall in-hospital mortality than those without demand ischemia (28 vs. 12%, p &lt; 0.001). After adjusting for clinical comorbidities and complications, demand ischemia was no longer associated with increased in-hospital mortality (OR: 1.14; 95% CI: 0.96–1.35; p = 0.141). However, further analysis with the exclusion of critically ill patients with non-cardiogenic shock or mechanical ventilation showed a significant association of demand ischemia with increased in-hospital mortality (adjusted OR: 1.39; 95% CI: 1.13–1.71; p = 0.002). Among non-critically ill survivors, patients with demand ischemia had a longer median LOS [4, (3–7) days] than those without demand ischemia [4, (2–6) days] (p &lt; 0.001). However, the difference was not statistically significant after adjustment for covariates.

Conclusion/Relevance

Demand ischemia did not affect mortality in critically sick patients. In non-critically ill patients, however, demand ischemia was significantly associated with increased in-hospital mortality, likely due to the severity of the underlying acute illness. Measures aimed at mitigating risk factors that contribute to delirium and/or demand ischemia need to be explored.

Can we improve delirium prevention and treatment in the emergency department? A systematic review

BACKGROUND

This systematic review was conducted to evaluate any interventions to prevent incident delirium, or shorten the duration of prevalent delirium, in older adults presenting to the emergency department (ED).

METHODS

Health sciences librarian designed electronic searches were conducted from database inception through September 2021. Two authors reviewed studies, and included studies that evaluated interventions for the prevention and/or treatment of delirium and excluded non-ED studies. The risk of bias (ROB) was evaluated by the Cochrane ROB tool or the Newcastle-Ottawa (NOS) scale. Meta-analysis was conducted to estimate a pooled effect of multifactorial programs on delirium prevention.

RESULTS

Our search strategy yielded 11,900 studies of which 10 met study inclusion criteria. Two RCTs evaluated pharmacologic interventions for delirium prevention; three non-RCTs employed a multi-factorial delirium prevention program; three non-RCTs evaluated regional anesthesia for hip fractures; and one study evaluated the use of Foley catheter, medication exposure, and risk of delirium. Only four studies demonstrated a significant impact on delirium incidence or duration of delirium-one RCT of melatonin reduced the incidence of delirium (OR 0.19, 95% CI 0.06 to 0.62), one non-RCT study on a multi-factorial program decreased inpatient delirium prevalence (41% to 19%) and the other reduced incident delirium (RR 0.37, 95% CI 0.22 to 0.61). One case-control study on the use of ED Foley catheters in the ED increased the duration of delirium (proportional OR 3.1, 95% CI 1.3 to 7.4). A pooled odds ratio for three multifactorial programs on delirium prevention was 0.46 (95% CI 0.31-0.68, I2  = 0).

CONCLUSION

Few interventions initiated in the ED were found to consistently reduce the incidence or duration of delirium. Delirium prevention and treatment trials in the ED are still rare and should be prioritized for future research.

Intraoperative low tidal volume ventilation and the risk of ICD-10 coded delirium and the use for antipsychotic medications

BACKGROUND

Low tidal volume (V_T) ventilation and its associated increase in arterial carbon dioxide (PaCO₂) may affect postoperative neurologic function. We aimed to test the hypothesis that intraoperative low V_T ventilation affect the incidence of postoperative ICD-10 coded delirium and/or the need for antipsychotic medications.

METHODS

This is a post-hoc analysis of a large randomized controlled trial evaluating low vs. conventional V_T ventilation during major non-cardiothoracic, non-intracranial surgery. The primary outcome was the incidence of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay, and the absolute difference with its 95% confidence interval (CI) was calculated.

RESULTS

We studied 1206 patients (median age of 64 [55-72] years, 59.0% males, median ARISCAT of 26 [19-37], and 47.6% of ASA 3). ICD-10 coded delirium and /or antipsychotic medication use was diagnosed in 11.2% with similar incidence between low and conventional V_T ventilation (11.1% vs. 11.3%; absolute difference, -0.24 [95%CI, -3.82 to 3.32]; p = 0.894). There was no interaction between allocation group and type of surgery.

CONCLUSION

In adult patients undergoing major surgery, low V_T ventilation was not associated with increased risk of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay.

TRIAL REGISTRATION

ANZCTR Identifier: ACTRN12614000790640 .

Gabapentinoid Use Is Associated With Reduced Occurrence of Hyperactive Delirium in Older Cancer Patients Undergoing Chemotherapy: A Nationwide Retrospective Cohort Study in Japan

BACKGROUND

It is unclear whether gabapentinoids affect the development of delirium. We aimed to determine the association between gabapentinoid use and hyperactive delirium in older cancer patients undergoing chemotherapy.

METHODS

We conducted propensity score-matched analyses using data from a nationwide inpatient database in Japan. We included cancer patients with pain ≥70 years of age undergoing chemotherapy between April 2016 and March 2018. Patients receiving gabapentinoids were matched with control patients using propensity scores. The primary outcome was occurrence of hyperactive delirium during hospitalization, and the secondary outcomes were length of hospital stay, in-hospital fractures, and in-hospital mortality. Hyperactive delirium was identified by antipsychotic use or discharge diagnoses from the International Classification of Diseases, 10th Revision.

RESULTS

Among 143,132 identified patients (59% men; mean age, 76.3 years), 14,174 (9.9%) received gabapentinoids and 128,958 (90.1%) did not (control group). After one-to-one propensity score matching, 14,173 patients were included in each group. The occurrence of hyperactive delirium was significantly lower (5.2% vs 8.5%; difference in percent, -3.2% [95% confidence interval, -3.8 to -2.6]; odds ratio, 0.60 [0.54-0.66]; P < .001), the median length of hospital stay was significantly shorter (6 days [interquartile range, 3-15] vs 9 days [4-17]; subdistribution hazard ratio, 1.22 [1.19-1.25]; P < .001), and the occurrence of in-hospital mortality was significantly lower in the gabapentinoid group than in the control group (1.3% vs 1.8%; difference in percent, -0.6% [-0.9 to -0.3]; odds ratio, 0.69 [0.57-0.83]; P < .001). Gabapentinoid use was not significantly associated with the occurrence of in-hospital fractures (0.2% vs 0.2%; difference in percent, 0.0% [-0.1 to 0.1]; odds ratio, 1.07 [0.65-1.76]; P = .799). The results of sensitivity analyses using stabilized inverse probability of treatment weighting were consistent with the results of the propensity score-matched analyses.

CONCLUSIONS

Our findings suggest that gabapentinoid use is associated with reduced hyperactive delirium in older cancer patients undergoing chemotherapy, with no evidence of an increase in the fracture rate, length of hospital stay, or in-hospital death.

Association Between Socioeconomic Disadvantage and Decline in Function, Cognition, and Mental Health After Critical Illness Among Older Adults : A Cohort Study

BACKGROUND

Older adults admitted to an intensive care unit (ICU) are at risk for developing impairments in function, cognition, and mental health. It is not known whether socioeconomically disadvantaged older persons are at greater risk for these impairments than their less vulnerable counterparts.

OBJECTIVE

To evaluate the association between socioeconomic disadvantage and decline in function, cognition, and mental health among older survivors of an ICU hospitalization.

DESIGN

Retrospective analysis of a longitudinal cohort study.

SETTING

Community-dwelling older adults in the National Health and Aging Trends Study (NHATS).

PARTICIPANTS

Participants with ICU hospitalizations between 2011 and 2017.

MEASUREMENTS

Socioeconomic disadvantage was assessed as dual-eligible Medicare-Medicaid status. The outcome of function was defined as the count of disabilities in 7 activities of daily living and mobility tasks, the cognitive outcome as the transition from no or possible to probable dementia, and the mental health outcome as the Patient Health Questionnaire-4 score in the NHATS interview after ICU hospitalization. The analytic sample included 641 ICU hospitalizations for function, 458 for cognition, and 519 for mental health.

RESULTS

After accounting for sociodemographic and clinical characteristics, dual eligibility was associated with a 28% increase in disability after ICU hospitalization (incidence rate ratio, 1.28; 95% CI, 1.00 to 1.64); and nearly 10-fold greater odds of transitioning to probable dementia (odds ratio, 9.79; 95% CI, 3.46 to 27.65). Dual eligibility was not associated with symptoms of depression and anxiety after ICU hospitalization (incidence rate ratio, 1.33; 95% CI, 0.99 to 1.79).

LIMITATION

Administrative data, variability in timing of baseline and outcome assessments, proxy selection.

CONCLUSION

Dual-eligible older persons are at greater risk for decline in function and cognition after an ICU hospitalization than their more advantaged counterparts. This finding highlights the need to prioritize low-income seniors in rehabilitation and recovery efforts after critical illness and warrants investigation into factors leading to this disparity.

PRIMARY FUNDING SOURCE

National Institute on Aging.

Outcomes of a Neurohospitalist Program at an Academic Medical Center

Background and Purpose

The purpose is to determine the impact of an academic neurohospitalist service on clinical outcomes.

Methods

We performed a retrospective, quasi-experimental study of patients discharged from the general neurology service before (August 2010–July 2014) and after implementation of a full-time neurohospitalist service (August 2016–July 2018) compared to a control group of stroke patients. Primary outcomes were length of stay and 30-day readmission. Using the difference-in-difference approach, the impact of introducing a neurohospitalist service compared to controls was assessed with adjustment of patients’ characteristics. Secondary outcomes included mortality, in-hospital complications, and cost.

Results

There were 2706 neurology admissions (1648 general; 1058 stroke) over the study period. The neurohospitalist service was associated with a trend in reduced 30-day readmissions (ratio of ORs: .52 [.27, .98], P = .088), while length of stay was not incrementally changed in the difference-in-difference model (-.3 [-.7, .1], P = .18). However, descriptive results demonstrated a significant reduction in mean adjusted LOS of .7 days (4.5 to 3.8 days, P < .001) and a trend toward reduced readmissions (8.9% to 7.6%, P = .42) in the post-neurohospitalist cohort despite a significant increase in patient complexity, shift to higher acuity diagnoses, more emergent admissions, and near quadrupling of observation status patients. Mortality and in-hospital complications remained low, patient satisfaction was stable, and cost was not incrementally changed in the post-neurohospitalist cohort.

Conclusions

Implementation of a neurohospitalist service at an academic medical center is feasible and associated with a significant increase in patient complexity and acuity and a trend toward reduced readmissions.

REcognizing DElirium in geriatric Emergency Medicine: The REDEEM risk stratification score

OBJECTIVE

The objective was to derive a risk score that uses variables available early during the emergency department (ED) encounter to identify high-risk geriatric patients who may benefit from delirium screening.

METHODS

This was an observational study of older adults age ≥ 75 years who presented to an academic ED and who were screened for delirium during their ED visit. Variable selection from candidate predictors was performed through a LASSO-penalized logistic regression. A risk score was derived from the final prediction model, and predictive accuracy characteristics were calculated with 95% confidence intervals (CIs).

RESULTS

From the 967 eligible ED visits, delirium was detected in 107 (11.1%). The area under the curve for the REcognizing DElirium in Emergency Medicine (REDEEM) score was 0.901 (95% CI = 0.864-0.938). The REEDEM risk score included 10 different variables (seven based on triage information and three obtained during early history taking) with a score ranging from -3 to 66. Using an optimal cutoff of ≥11, we found a sensitivity of 84.1% (90 of 107 ED delirium patients, 95% CI = 75.5%-90.2%) and a specificity of 86.6% (745 of 860 non-ED delirium patients, 95% CI = 84.1%-88.8%). A lower cutoff of ≥5 was found to minimize false negatives with an improved sensitivity at 91.6% (98 of 107 ED delirium patients, 95% CI = 84.2%-95.8%).

CONCLUSION

A risk stratification score was derived with the potential to augment delirium recognition in geriatric ED patients. This has the potential to assist on delirium-targeted screening of high-risk patients in the ED. Validation of REDEEM, however, is needed prior to implementation.

Inpatient Diagnosis of Delirium and Encephalopathy: Coding Trends 2011-2018

OBJECTIVES

Ten medical societies have called for scientific literature to integrate research on delirium and encephalopathy, while physicians continually debate how to accurately document diagnoses of acute confusional states. To promote this integration, we evaluated trends in diagnoses of delirium and encephalopathy among hospitalized adults and physician specialties, incorporating transitions to the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) and the International Classification of Disease-10 (ICD-10).

METHODS

Using 2011-2018 IBM MarketScan datasets, we identified delirium/encephalopathy patients ≥ 18 years using ICD-9/10 codes among hospitalized patients. We identified physician specialties associated with the hospitalization and comorbidities within one year prior to the diagnosis of delirium or encephalopathy. Log-binomial models were used to evaluate diagnostic trends, adjusting for age, gender, insurance and comorbidities.

RESULTS

We identified 10,509 hospitalized patients with diagnosis of delirium and 94,438 with encephalopathy between 2011-2018. Although the number of patients with either diagnosis increased over time, increased use of delirium diagnosis was less than it was for encephalopathy compared to 2011 after adjusting for covariates (ARR 0.45; 95% CI 0.43 to 0.48). During the 8 years, neurologists and internists increased their use of both diagnoses, whereas psychiatrists only increased their use of delirium. Family practice physicians and nurse practitioners presented no significant change in either diagnosis for this timeframe.

CONCLUSIONS

Our results suggest that refined diagnostic codes and criteria may alter trends among clinicians in diagnosing delirium and/or encephalopathy. Additional diagnostic clarity may be necessary to support refined diagnoses among family practice physicians and nurse practitioners.

Longitudinal validation of an electronic health record delirium prediction model applied at admission in COVID-19 patients

OBJECTIVE

To validate a previously published machine learning model of delirium risk in hospitalized patients with coronavirus disease 2019 (COVID-19).

METHOD

Using data from six hospitals across two academic medical networks covering care occurring after initial model development, we calculated the predicted risk of delirium using a previously developed risk model applied to diagnostic, medication, laboratory, and other clinical features available in the electronic health record (EHR) at time of hospital admission. We evaluated the accuracy of these predictions against subsequent delirium diagnoses during that admission.

RESULTS

Of the 5102 patients in this cohort, 716 (14%) developed delirium. The model's risk predictions produced a c-index of 0.75 (95% CI, 0.73-0.77) with 27.7% of cases occurring in the top decile of predicted risk scores. Model calibration was diminished compared to the initial COVID-19 wave.

CONCLUSION

This EHR delirium risk prediction model, developed during the initial surge of COVID-19 patients, produced consistent discrimination over subsequent larger waves; however, with changing cohort composition and delirium occurrence rates, model calibration decreased. These results underscore the importance of calibration, and the challenge of developing risk models for clinical contexts where standard of care and clinical populations may shift.

An Inpatient Geriatrics Program with a Focus on Any Type of Cognitive Impairment Reduces Mortality

BACKGROUND

No matter what type of cognitive impairment an older hospitalized patient has, the risk of mortality is increased.

OBJECTIVES

To describe a hospital-based geriatrics program with a focus on any type of cognitive impairment and to determine whether this program was associated with reduced mortality over time.

DESIGN, PARTICIPANTS AND SETTING

Retrospective chart review of all patients age 70+ admitted during a 3-year period (2017-2019, N=20,401), to a 500-bed community-based hospital (Level 1 Trauma Center and Stroke Center).

INTERVENTION

A multicomponent geriatrics program was developed and implemented throughout 2018 and included: geriatric consultation, data collection, review of the data with hospital leaders, a geriatrics task force, clinician education and a Delirium Unit.

MAIN OUTCOMES AND MEASURES

Monthly mortality rates for patients with and without cognitive impairment over the 3-year period. To control for other variables associated with mortality, pre-post implementation analyses were performed (2017 versus 2019).

RESULTS

A linear regression analysis showed a significant downward trend in mortality over time for patients with cognitive impairment [R2=0.4, P<.0001, (correlation coefficient -0.6, 95% CI, -0.8 to -0.4)] but not among patients without cognitive impairment [R2=0.0, P=0.829, (correlation coefficient 0.0, 95% CI, -0.3 to 0.3)]. When controlling for other variables, there was still a decrease in mortality risk among patients with cognitive impairment.

CONCLUSION

Although there are limitations to this study, a multicomponent geriatrics program with an emphasis on any type of cognitive impairment, may be associated with improved mortality.

Use of naldemedine is associated with reduced incidence of hyperactive delirium in cancer patients with opioid-induced constipation: a nationwide retrospective cohort study in Japan

BACKGROUND

Medical benefits of peripherally-acting mu-opioid receptor antagonists other than improving opioid-induced constipation remain unclear. Our aim was to evaluate the association between the use of naldemedine and incidence of hyperactive delirium in cancer patients receiving chemotherapy and opioid therapy.

METHODS

We conducted a propensity score-matched analysis using a nationwide inpatient database in Japan. Cancer patients receiving both inpatient chemotherapy and opioid therapy from June 1, 2017 to March 31, 2018 were included. Patients receiving naldemedine were matched to control patients by propensity score. Our primary outcome was the incidence of hyperactive delirium during hospitalization, and secondary outcomes were the length of hospital stay, hospital costs, in-hospital mortality, and incidence of ileus.

RESULTS

Of 34,031 patients receiving inpatient chemotherapy and opioid therapy, 1905 (5.6%) were included in the naldemedine group. After one-to-four propensity score matching, 1904 patients were included in the naldemedine group and 7616 in the control group. Naldemedine users had significantly reduced incidence of hyperactive delirium compared with the control patients (19.4% vs 23.3%; risk difference, -3.9 [95% confidence interval, -5.9 - -1.9]; risk ratio, 0.83 [0.75-0.92]; P<0.001; subdistribution hazard ratio, 0.85 [0.75-0.97]; P=0.015). The median length of hospital stay was significantly shorter in the naldemedine group compared with the control group (12 days [interquartile range, 6-23] vs 14 days [6-26]; P=0.001). The median hospital costs were also significantly lower in the naldemedine group compared with the control group (US $6179 [3351-10,026] vs US $6576 [3436-11,107]; P<0.001). No significant differences were found for in-hospital mortality or incidence of ileus between the groups.

CONCLUSIONS

Our findings suggest that the use of naldemedine may have benefits in preventing hyperactive delirium, shortening hospital stay, and decreasing hospital costs in cancer patients receiving chemotherapy and opioid therapy.

Detecting Incident Delirium within Routinely Collected Inpatient Rehabilitation Data: Validation of a Chart-Based Method

Background: Delirium is a brain condition associated with poor outcomes in rehabilitation. It is therefore important to assess delirium incidence in rehabilitation. Purpose: To develop and validate a chart-based method to identify incident delirium episodes within the electronic database of a Swiss rehabilitation clinic, and to identify a study population of validated incident delirium episodes for further research purposes. Design: Retrospective validation study. Settings: Routinely collected inpatient clinical data from ZURZACH Care. Participants: All patients undergoing rehabilitation at ZURZACH Care, Rehaklinik Bad Zurzach between 2015 and 2018 were included. Methods: Within the study population, we identified all rehabilitation stays for which ≥2 delirium-predictive key words (common terms used to describe delirious patients) were recorded in the medical charts. We excluded all prevalent delirium episodes and defined the remaining episodes to be potentially incident. At least two physicians independently confirmed or refuted each potential incident delirium episode by reviewing the patient charts. We calculated the positive predictive value (PPV) with 95% confidence interval (95% CI) for all potential incident delirium episodes and for specific subgroups. Results: Within 10,515 rehabilitation stays we identified 554 potential incident delirium episodes. Overall, 125 potential incident delirium episodes were confirmed by expert review. The PPV of the chart-based method varied from 0.23 (95% CI 0.19–0.26) overall to 0.69 (95% CI 0.56–0.79) in specific subgroups. Conclusions: Our chart-based method was able to capture incident delirium episodes with low to moderate accuracy. By conducting an additional expert review of the medical charts, we identified a study population of validated incident delirium episodes. Our chart-based method contributes towards an automated detection of potential incident delirium episodes that, supplemented with expert review, efficiently yields a validated population of incident delirium episodes for research purposes.

Comparing LASSO and random forest models for predicting neurological dysfunction among fluoroquinolone users

BACKGROUND

Fluoroquinolones are associated with central (CNS) and peripheral (PNS) nervous system symptoms, and predicting the risk of these outcomes may have important clinical implications. Both LASSO and random forest are appealing modeling methods, yet it is not clear which method performs better for clinical risk prediction.

PURPOSE

To compare models developed using LASSO versus random forest for predicting neurological dysfunction among fluoroquinolone users.

METHODS

We developed and validated risk prediction models using claims data from a commercially insured population. The study cohort included adults dispensed an oral fluoroquinolone, and outcomes were CNS and PNS dysfunction. Model predictors included demographic variables, comorbidities and medications known to be associated with neurological symptoms, and several healthcare utilization predictors. We assessed the accuracy and calibration of these models using measures including AUC, calibration curves, and Brier scores.

RESULTS

The underlying cohort contained 16 533 (1.18%) individuals with CNS dysfunction and 46 995 (3.34%) individuals with PNS dysfunction during 120 days of follow-up. For CNS dysfunction, LASSO had an AUC of 0.81 (95% CI: 0.80, 0.82), while random forest had an AUC of 0.80 (95% CI: 0.80, 0.81). For PNS dysfunction, LASSO had an AUC of 0.75 (95% CI: 0.74, 0.76) versus an AUC of 0.73 (95% CI: 0.73, 0.74) for random forest. Both LASSO models had better calibration, with Brier scores 0.17 (LASSO) versus 0.20 (random forest) for CNS dysfunction and 0.20 (LASSO) versus 0.25 (random forest) for PNS dysfunction.

CONCLUSIONS

LASSO outperformed random forest in predicting CNS and PNS dysfunction among fluoroquinolone users, and should be considered for modeling when the cohort is modest in size, when the number of model predictors is modest, and when predictors are primarily binary.

The Utilization and Costs of Grade D USPSTF Services in Medicare, 2007-2016

BACKGROUND

Low-value care, or patient care that offers no net benefit in specific clinical scenarios, is costly and often associated with patient harm. The US Preventive Services Task Force (USPSTF) Grade D recommendations represent one of the most scientifically sound and frequently delivered groups of low-value services, but a more contemporary measurement of the utilization and spending for Grade D services beyond the small number of previously studied measures is needed.

OBJECTIVE

To estimate utilization and costs of seven USPSTF Grade D services among US Medicare beneficiaries.

DESIGN

We conducted a cross-sectional study of data from the National Ambulatory Medical Care Survey (NAMCS) from 2007 to 2016 to identify instances of Grade D services.

SETTING/PARTICIPANTS

NAMCS is a nationally representative survey of US ambulatory visits at non-federal and non-hospital-based offices that uses a multistage probability sampling design. We included all visits by Medicare enrollees, which included traditional fee-for-service, Medicare Advantage, supplemental coverage, and dual-eligible Medicare-Medicaid enrollees.

MAIN MEASURES

We measured annual utilization of seven Grade D services among adult Medicare patients, using inclusion and exclusion criteria from prior studies and the USPSTF recommendations. We calculated annual costs by multiplying annual utilization counts by mean per-unit costs of services using publicly available sources.

KEY RESULTS

During the study period, we identified 95,121 unweighted Medicare patient visits, representing approximately 2.4 billion visits. Each year, these seven Grade D services were utilized 31.1 million times for Medicare beneficiaries and cost $477,891,886. Three services-screening for asymptomatic bacteriuria, vitamin D supplements for fracture prevention, and colorectal cancer screening for adults over 85 years-comprised $322,382,772, or two-thirds of the annual costs of the Grade D services measured in this study.

CONCLUSIONS

US Medicare beneficiaries frequently received a group of rigorously defined and costly low-value preventive services. Spending on low-value preventive care concentrated among a small subset of measures, representing important opportunities to safely lower US health care spending while improving the quality of care.

Identifying patients with delirium based on unstructured clinical notes. (Preprint)

Background

Delirium in hospitalized patients is a syndrome of acute brain dysfunction. Diagnostic (International Classification of Diseases [ICD]) codes are often used in studies using electronic health records (EHRs), but they are inaccurate.

Objective

We sought to develop a more accurate method using natural language processing (NLP) to detect delirium episodes on the basis of unstructured clinical notes.

Methods

We collected 1.5 million notes from >10,000 patients from among 9 hospitals. Seven experts iteratively labeled 200,471 sentences. Using these, we trained three NLP classifiers: Support Vector Machine, Recurrent Neural Networks, and Transformer. Testing was performed using an external data set. We also evaluated associations with delirium billing (ICD) codes, medications, orders for restraints and sitters, direct assessments (Confusion Assessment Method [CAM] scores), and in-hospital mortality. F1 scores, confusion matrices, and areas under the receiver operating characteristic curve (AUCs) were used to compare NLP models. We used the φ coefficient to measure associations with other delirium indicators.

Results

The transformer NLP performed best on the following parameters: micro F1=0.978, macro F1=0.918, positive AUC=0.984, and negative AUC=0.992. NLP detections exhibited higher correlations (φ) than ICD codes with deliriogenic medications (0.194 vs 0.073 for ICD codes), restraints and sitter orders (0.358 vs 0.177), mortality (0.216 vs 0.000), and CAM scores (0.256 vs –0.028).

Conclusions

Clinical notes are an attractive alternative to ICD codes for EHR delirium studies but require automated methods. Our NLP model detects delirium with high accuracy, similar to manual chart review. Our NLP approach can provide more accurate determination of delirium for large-scale EHR-based studies regarding delirium, quality improvement, and clinical trails.

Association Between Intraoperative Arterial Hypotension and Postoperative Delirium After Noncardiac Surgery: A Retrospective Multicenter Cohort Study

BACKGROUND

It is unclear whether intraoperative arterial hypotension is associated with postoperative delirium. We hypothesized that intraoperative hypotension within a range frequently observed in clinical practice is associated with increased odds of delirium after surgery.

METHODS

Adult noncardiac surgical patients undergoing general anesthesia at 2 academic medical centers between 2005 and 2017 were included in this retrospective cohort study. The primary exposure was intraoperative hypotension, defined as the cumulative duration of an intraoperative mean arterial pressure (MAP) <55 mm Hg, categorized into and short (<15 minutes; median [interquartile range {IQR}], 2 [1-4] minutes) and prolonged (≥15 minutes; median [IQR], 21 [17-31] minutes) durations of intraoperative hypotension. The primary outcome was a new diagnosis of delirium within 30 days after surgery. In secondary analyses, we assessed the association between a MAP decrease of >30% from baseline and postoperative delirium. Multivariable logistic regression adjusted for patient- and procedure-related factors, including demographics, comorbidities, and markers of procedural severity, was used.

RESULTS

Among 316,717 included surgical patients, 2183 (0.7%) were diagnosed with delirium within 30 days after surgery; 41.7% and 2.6% of patients had a MAP <55 mm Hg for a short and a prolonged duration, respectively. A MAP <55 mm Hg was associated with postoperative delirium compared to no hypotension (short duration of MAP <55 mm Hg: adjusted odds ratio [ORadj], 1.22; 95% confidence interval [CI], 1.11-1.33; P < .001 and prolonged duration of MAP <55 mm Hg: ORadj, 1.57; 95% CI, 1.27-1.94; P < .001). Compared to a short duration of a MAP <55 mm Hg, a prolonged duration of a MAP <55 mm Hg was associated with greater odds of postoperative delirium (ORadj, 1.29; 95% CI, 1.05-1.58; P = .016). The association between intraoperative hypotension and postoperative delirium was duration-dependent (ORadj for every 10 cumulative minutes of MAP <55 mm Hg: 1.06; 95% CI, 1.02-1.09; P =.001) and magnified in patients who underwent surgeries of longer duration (P for interaction = .046; MAP <55 mm Hg versus no MAP <55 mm Hg in patients undergoing surgery of >3 hours: ORadj, 1.40; 95% CI, 1.23-1.61; P < .001). A MAP decrease of >30% from baseline was not associated with postoperative delirium compared to no hypotension, also when additionally adjusted for the cumulative duration of a MAP <55 mm Hg (short duration of MAP decrease >30%: ORadj, 1.13; 95% CI, 0.91-1.40; P = .262 and prolonged duration of MAP decrease >30%: ORadj, 1.19; 95% CI, 0.95-1.49; P = .141).

CONCLUSIONS

In patients undergoing noncardiac surgery, a MAP <55 mm Hg was associated with a duration-dependent increase in odds of postoperative delirium. This association was magnified in patients who underwent surgery of long duration.

Association of Histamine-2 Blockers and Proton-Pump Inhibitors With Delirium Development in Critically Ill Adults: A Retrospective Cohort Study

Supplemental Digital Content is available in the text.

OBJECTIVES:

Histamine-2 receptor antagonists are commonly administered for stress ulcer prophylaxis in critically ill adults and may be associated with delirium development. We aimed to determine differential associations of histamine-2 receptor antagonist or proton-pump inhibitor administration with delirium development in patients admitted to a medical ICU.

DESIGN:

Retrospective observational study using a deidentified database sourced from the University of North Carolina Health Care system. Participants were identified as having delirium utilizing an International Classification of Diseases-based algorithm. Associations among histamine-2 receptor antagonist, proton-pump inhibitor, or no medication administration and delirium were identified using relative risk. Multiple logistic regression was used to control for potential confounders including mechanical ventilation and age.

SETTING:

Academic tertiary care medical ICU in the United States.

PATIENTS:

Adults admitted to the University of North Carolina medical ICU from January 2015 to December 2019, excluding those on concurrent histamine-2 receptor antagonists and proton-pump inhibitors in the same encounter.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

We identified 6,645 critically ill patients, of whom 29% (n = 1,899) received mechanical ventilation, 45% (n = 3,022) were 65 or older, and 22% (n = 1,487) died during their medical ICU encounter. Of the 6,645 patients, 31% (n = 2,057) received an histamine-2 receptor antagonist and no proton-pump inhibitors, 40% (n = 2,648) received a proton-pump inhibitor and no histamine-2 receptor antagonists, and 46% (n = 3,076) had delirium. The histamine-2 receptor antagonist group had a greater association with delirium than the proton-pump inhibitor group compared with controls receiving neither medication, after controlling for mechanical ventilation and age (risk ratio, 1.36; 1.25–1.47; p < 0.001) and (risk ratio, 1.15; 1.07–1.24; p < 0.001, respectively).

CONCLUSIONS:

Histamine-2 receptor antagonists are more strongly associated with increased delirium than proton-pump inhibitors. Prospective studies are necessary to further elucidate this association and to determine if replacement of histamine-2 receptor antagonists with proton-pump inhibitors in ICUs decreases the burden of delirium in critically ill patients.

Frailty is associated with a higher risk of developing delirium and cognitive impairment among patients with diabetic kidney disease: A longitudinal population-based cohort study

AIMS

Delirium, a form of acute brain failure, exhibits a high incidence among older adults. Recent studies have implicated frailty as an under-recognized complication of diabetes mellitus. Whether the presence of frailty increases the risk of delirium/cognitive impairment among patients with diabetic kidney disease (DKD) remains unclear.

METHODS

From the longitudinal cohort of diabetes patients (LCDP) (n = 840,000) in Taiwan, we identified adults with DKD, dividing them into those without and with different severities of frailty based on a modified FRAIL scale. Cox proportional hazard regression was utilized to examine the frailty-associated risk of delirium/cognitive impairment, identified using approaches validated by others.

RESULTS

Totally 149,145 patients with DKD (mean 61.0 years, 44.2% female) were identified, among whom 31.0%, 51.7%, 16.0% and 1.3% did not have or had 1, 2 and >2 FRAIL items at baseline. After 3.68 years, 6613 (4.4%) developed episodes of delirium/cognitive impairment. After accounting for demographic/lifestyle factors, co-morbidities, medications and interventions, patients with DKD and 1, 2 and >2 FRAIL items had a progressively higher risk of developing delirium/cognitive impairment than those without (for those with 1, 2 and >2 items, hazard ratio 1.18, 1.26 and 1.30, 95% confidence interval 1.08-1.28, 1.14-1.39 and 1.10-1.55, respectively). For every FRAIL item increase, the associated risk rose by 9%.

CONCLUSIONS

Frailty significantly increased the risk of delirium/cognitive impairment among patients with DKD. Frailty screening in these patients may assist in delirium risk stratification.