Use of the All Patient Refined-Diagnosis Related Group (APR-DRG) Risk of Mortality Score as a Severity Adjustor in the Medical ICU

Dialysis-requiring acute kidney injury among hospitalized adults with documented hepatitis C Virus infection: a nationwide inpatient sample analysis

Chronic hepatitis C virus (HCV) infection may cause kidney injury, particularly in the setting of cryoglobulinemia or cirrhosis; however, few studies have evaluated the epidemiology of acute kidney injury in patients with HCV. We aimed to describe national temporal trends of incidence and impact of severe acute kidney injury (AKI) requiring renal replacement 'dialysis-requiring AKI' in hospitalized adults with HCV. We extracted our study cohort from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project using data from 2004 to 2012. We defined HCV and dialysis-requiring acute kidney injury based on previously validated ICD-9-CM codes. We analysed temporal changes in the proportion of hospitalizations complicated by dialysis-requiring AKI and utilized survey multivariable logistic regression models to estimate its impact on in-hospital mortality. We identified a total of 4,603,718 adult hospitalizations with an associated diagnosis of HCV from 2004 to 2012, of which 51,434 (1.12%) were complicated by dialysis-requiring acute kidney injury. The proportion of hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly from 0.86% in 2004 to 1.28% in 2012. In-hospital mortality was significantly higher in hospitalizations complicated by dialysis-requiring acute kidney injury vs those without (27.38% vs 2.95%; adjusted odds ratio: 2.09; 95% confidence interval: 1.74-2.51). The proportion of HCV hospitalizations complicated by dialysis-requiring acute kidney injury increased significantly between 2004 and 2012. Similar to observations in the general population, dialysis-requiring acute kidney injury was associated with a twofold increase in odds of in-hospital mortality in adults with HCV. These results highlight the burden of acute kidney injury in hospitalized adults with HCV infection.

Propofol Use in the Elderly Population: Prevalence of Overdose and Association With 30-Day Mortality

PURPOSE

Geriatric patients are more sensitive to the anesthetic effects of propofol and its adverse effects, such as hypotension, than is the general population; thus, a reduced dose (1-1.5 mg/kg) is recommended for the induction of anesthesia. The extent to which clinicians follow established dosing guidelines has not been well described. Therefore, we investigated the prevalence of propofol overdose in the elderly population to determine whether propofol overdose occurs and is associated with increased hypotension and 30-day mortality.

METHODS

In this retrospective study in patients who received propofol for the induction of general anesthesia, data on demographic characteristics, preoperative medications, intraoperative management, and 30-day mortality were collected. The dose of propofol used for the induction of anesthesia and the median blood pressure in the pre- and immediate postinduction periods were determined. Hypotension was defined as either: (1) a decrease in mean arterial pressure (MAP) of >40% concurrent with a MAP of <70 mm Hg; or (2) a MAP of <60 mm Hg.

FINDINGS

A total of 17,540 patients were included in the analysis; 4033 (23.0%) were aged >65 years. The median (interquartile range) propofol dose in the group aged >65 years was 1.8 (1.4-2.2) mg/kg, above the recommended dose, in comparison to 2.2 (1.9-2.5) mg/kg in younger patients. On multivariate analysis, increased propofol dose was associated with increased postinduction hypotension, especially in patients over 70 years of age, but not 30-day mortality.

IMPLICATIONS

Older patients received greater-than-recommended doses of propofol for induction, which may have led to significant dose-dependent hypotension. Despite this finding, the dose of propofol for induction was not independently associated with a greater 30-day mortality rate. More education regarding geriatric concerns is needed for encouraging anesthesiologists to tailor the plan for anesthesia in geriatric patients. However, overall postsurgical mortality is a function of preoperative risk and type surgical procedure.

Carotid Artery Stenosis with Acute Ischemic Stroke: Stenting versus Angioplasty

BACKGROUND

When a patient with carotid artery stenosis presents emergently with acute ischemic stroke, the optimum treatment plan is not clearly defined. If intervention is warranted, and open surgery is prohibitive, endovascular revascularization may be performed. The use of stents places the patient at additional risk due to their thrombogenic potential. The intent of this study was to compare outcomes following endovascular approaches (angioplasty alone vs. stent) in the setting of acute stroke.

METHODS

We extracted a population from the National Inpatient Sample (2012) and the Nationwide Inpatient Sample (2003-2011) composed of patients with carotid artery stenosis with infarction that were admitted nonelectively and received endovascular revascularization. Patients treated with mechanical thrombectomy or thrombolysis were excluded. Categorical variables were compared between treatment groups with Chi-squared tests. Binary logistic regression was performed to evaluate mortality and iatrogenic stroke while controlling for age, case severity, and comorbidity burden.

RESULTS

About 6,333 admissions met our criteria. A majority were treated via stenting (89%, n = 5,608). The angioplasty-alone group had significantly higher mortality (9.0% vs. 3.8%, p < 0.001) and iatrogenic stroke rate (3.9% vs. 1.9%, p < 0.001) than the stent group. The adjusted odds ratios of mortality and iatrogenic stroke for patients treated with angioplasty alone were 1.953 (p < 0.001) and 1.451 (p = 0.105), respectively, in comparison to patients treated with carotid stenting.

CONCLUSION

Multivariate analysis found the risk of mortality to be elevated following angioplasty alone. This may represent selection bias, but it also may indicate that symptomatic patients with stroke suffer from severe stenosis and unstable plaques that would benefit from stent placement. These results would caution angioplasty alone as an arm of a future randomized trial involving this severely burdened patient population requiring urgent intervention.

A Nationwide Analysis of Outcomes of Weekend Admissions for Intracerebral Hemorrhage Shows Disparities Based on Hospital Teaching Status

BACKGROUND AND PURPOSE

With the "weekend effect" being well described, the Brain Attack Coalition released a set of "best practice" guidelines in 2005, with the goal to uniformly provide standard of care to patients with stroke. We attempted to define a "weekend effect" in outcomes among patients with intracranial hemorrhage (ICH) over the last decade, utilizing the Nationwide Inpatient Sample (NIS) data. We also attempted to analyze the trend of such an effect.

MATERIALS AND METHODS

We determined the association of ICH weekend admissions with hospital outcomes including mortality, adverse discharge, length of stay, and cost compared to weekday admissions using multivariable logistic regression. We extracted our study cohort from the NIS, the largest all-payer data set in the United States.

RESULTS

Of 485 329 ICH admissions from 2002 to 2011, 27.5% were weekend admissions. Overall, weekend admissions were associated with 11% higher odds of in-hospital mortality. When analyzed in 3-year groups, excess mortality of weekend admissions showed temporal decline. There was higher mortality with weekend admissions in nonteaching hospitals persisted (odds ratios 1.16, 1.13, and 1.09, respectively, for 3-year subgroups). Patients admitted during weekends were also 9% more likely to have an adverse discharge (odds ratio 1.09; 95% confidence interval: 1.07-1.11; P < .001) with no variation by hospital status. There was no effect of a weekend admission on either length of stay or cost of care.

CONCLUSION

Nontraumatic ICH admissions on weekends have higher in-hospital mortality and adverse discharge. This demonstrates need for in-depth review for elucidating this discrepancy and stricter adherence to standard-of-care guidelines to ensure uniform care.

Risk-Adjusted In-Hospital Mortality Models for Congestive Heart Failure and Acute Myocardial Infarction: Value of Clinical Laboratory Data and Race/Ethnicity

OBJECTIVE

To examine the impact of key laboratory and race/ethnicity data on the prediction of in-hospital mortality for congestive heart failure (CHF) and acute myocardial infarction (AMI).

DATA SOURCES

Hawaii adult hospitalizations database between 2009 and 2011, linked to laboratory database.

STUDY DESIGN

Cross-sectional design was employed to develop risk-adjusted in-hospital mortality models among patients with CHF (n = 5,718) and AMI (n = 5,703).

DATA COLLECTION/EXTRACTION METHODS

Results of 25 selected laboratory tests were requested from hospitals and laboratories across the state and mapped according to Logical Observation Identifiers Names and Codes standards. The laboratory data were linked to administrative data for each discharge of interest from an all-payer database, and a Master Patient Identifier was used to link patient-level encounter data across hospitals statewide.

PRINCIPAL FINDINGS

Adding a simple three-level summary measure based on the number of abnormal laboratory data observed to hospital administrative claims data significantly improved the model prediction for inpatient mortality compared with a baseline risk model using administrative data that adjusted only for age, gender, and risk of mortality (determined using 3M's All Patient Refined Diagnosis Related Groups classification). The addition of race/ethnicity also improved the model.

CONCLUSIONS

The results of this study support the incorporation of a simple summary measure of laboratory data and race/ethnicity information to improve predictions of in-hospital mortality from CHF and AMI. Laboratory data provide objective evidence of a patient's condition and therefore are accurate determinants of a patient's risk of mortality. Adding race/ethnicity information helps further explain the differences in in-hospital mortality.

The burden of dialysis-requiring acute kidney injury among hospitalized adults with HIV infection: a nationwide inpatient sample analysis

OBJECTIVE

The objective of this study was to describe the incidence of acute kidney injury (AKI) requiring renal replacement therapy ('dialysis-requiring AKI') and the impact on in-hospital mortality among hospitalized adults with HIV infection.

DESIGN

A longitudinal analysis of a nationally representative administrative database.

METHODS

We reviewed the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample Database, a large, nationally representative sample of inpatient hospital admissions, to identify all adult hospitalizations with an associated diagnosis of HIV infection from 2002 to 2010. We analysed temporal trends in the incidence of dialysis-requiring AKI and the associated odds of in-hospital mortality. We also explored potential reasons behind temporal changes.

RESULTS

Among 183 0041 hospitalizations with an associated diagnosis of HIV infection, the proportion complicated by dialysis-requiring AKI increased from 0.7% in 2002 to 1.35% in 2010. This temporal rise was completely explained by changes in demographics and an increase in concurrent comorbidities and procedure utilization. The adjusted odds of in-hospital mortality associated with dialysis-requiring AKI also increased over the study period, from 1.45 [95% confidence interval (95% CI) 0.97-2.12] in 2002 to 2.64 (95% CI 2.04-3.42) in 2010.

CONCLUSION

These data suggest that the incidence of dialysis-requiring AKI among hospitalized adults with HIV infection continues to increase, and that severe AKI remains a significant predictor of in-hospital mortality in this population. The increased incidence of dialysis-requiring AKI was largely explained by ageing of the HIV population and increasing prevalence of chronic non-AIDS comorbidities, suggesting that these trends will continue.

Retrospective Evaluation of the Epidemiology and Practice Variation of Dexmedetomidine Use in Invasively Ventilated Pediatric Intensive Care Admissions, 2007-2013

OBJECTIVES

The study assessed dexmedetomidine utilization and practice variation over time in ventilated pediatric intensive care unit (PICU) patients; and evaluated differences in hospital outcomes between high- and low-dexmedetomidine utilization hospitals.

STUDY DESIGN

This serial cross-sectional analysis used administrative data from PICU admissions in the pediatric health information system (37 US tertiary care pediatric hospitals). Included admissions from 2007 to 2013 had simultaneous dexmedetomidine and invasive mechanical ventilation charges, <18 years of age, excluding neonates. Patient and hospital characteristics were compared as well as hospital-level severity-adjusted indexed length of stay (LOS), charges, and mortality.

RESULTS

The utilization of dexmedetomidine increased from 6.2 to 38.2 per 100 ventilated PICU patients among pediatric hospitals. Utilization ranged from 3.8 to 62.8 per 100 in 2013. Few differences in patient demographics and no differences in hospital-level volume/severity of illness measures between high- and low-utilization hospitals occurred. No differences in hospital-level, severity-adjusted indexed outcomes (LOS, charges, and mortality) were found.

CONCLUSION

Wide practice variation in utilization of dexmedetomidine for ventilated PICU patients existed even as use has increased sixfold. Higher utilization was not associated with increased hospital charges or reduced hospital LOS. Further work should define the expected outcome benefits of dexmedetomidine and its appropriate use.

Intraventricular thrombolysis in intracerebral hemorrhage requiring ventriculostomy: a decade-long real-world experience

BACKGROUND AND PURPOSE

Intraventricular thrombolysis (IVT) is a promising treatment in facilitating intraventricular clot resolution after intraventricular hemorrhage. We examined in-hospital outcomes and resource utilization after thrombolysis in patients with intraventricular hemorrhage requiring ventriculostomy in a real-world setting.

METHODS

We identified adult patients with primary diagnosis of nontraumatic intracerebral hemorrhage requiring ventriculostomy from the Nationwide Inpatient Sample from 2002 to 2011. We compared demographic and hospital characteristics, comorbidities, inpatient outcomes, and resource utilization measures between patients treated with IVT and those managed with ventriculostomy, but without IVT. Population estimates were extrapolated using standard Nationwide Inpatient Sample weighting algorithms.

RESULTS

We included 34 044 patients in the analysis, of whom 1133 (3.3%) received IVT. The thrombolysis group had significantly lower inpatient mortality (32.4% versus 41.6%; P=0.001) and it remained lower after controlling for baseline demographics, hospital characteristics, comorbidity, case severity, and withdrawal of care status (adjusted odds ratio, 0.670; 95% confidence interval, 0.520-0.865; P=0.002). There was a trend toward favorable discharge (home or rehabilitation) among the thrombolysis cohort (adjusted odds ratio, 1.335; 95% confidence interval, 0.983-1.812; P=0.064). The adjusted rates of bacterial meningitis and ventricular shunt placement were similar between groups. The thrombolysis group had longer length of stay and higher inflation-adjusted cost of care, but cost of care per day length of stay was similar to the non-IVT group.

CONCLUSIONS

IVT for intracerebral hemorrhage requiring ventriculostomy resulted in lower inpatient mortality and a trend toward favorable discharge outcome with similar rates of inpatient complications compared with the non-IVT group.

Risk-adjusted clinical outcomes in patients enrolled in a bloodless program

BACKGROUND

Although clinical outcomes have been reported for patients who do not accept allogeneic blood transfusion (ABT), many previous studies lack a control group, fail to use risk adjustment, and focus exclusively on cardiac surgery.

STUDY DESIGN AND METHODS

We report a risk-adjusted, propensity score-matched, retrospective case-control study of clinical outcomes for inpatients who did not accept ABT (bloodless, n = 294) and those who did accept ABT (control, n = 1157). Multidisciplinary specialized care was rendered to the bloodless patients to conserve blood and optimize clinical outcomes. Differences in hemoglobin (Hb), mortality, five morbid outcomes, and hospital charges and costs were compared. Subgroups of medical and surgical patients were analyzed, and independent predictors of outcome were determined by multivariate analysis.

RESULTS

Overall, mortality was lower in the bloodless group (0.7%) than in the control group (2.7%; p = 0.046), primarily attributed to the surgical subgroup. After risk adjustment, bloodless care was not an independent predictor of the composite adverse outcome (death or any morbid event; p = 0.91; odds ratio, 1.02; 95% confidence interval, 0.68-1.53). Discharge Hb concentrations were similar in the bloodless (10.8 ± 2.7 g/dL) and control (10.9 ± 2.3 g/dL) groups (p = 0.42). Total and direct hospital costs were 12% (p = 0.02) and 18% (p = 0.02) less, respectively, in the bloodless patients, a difference attributed to the surgical subgroup.

CONCLUSIONS

Using appropriate blood conservation measures for patients who do not accept ABT results in similar or better outcomes and is associated with equivalent or lower costs. This specialized care may be beneficial even for those patients who accept ABT.

Accuracy of the all patient refined diagnosis related groups classification system in congenital heart surgery

BACKGROUND

Administrative data are increasingly used to evaluate clinical outcomes and quality of care in pediatric congenital heart surgery (CHS) programs. Several published analyses of large pediatric administrative data sets have relied on the All Patient Refined Diagnosis Related Groups (APR-DRG, version 24) diagnostic classification system. The accuracy of this classification system for patients undergoing CHS is unclear.

METHODS

We performed a retrospective cohort study of all 14,098 patients 0 to 5 years of age undergoing any of six selected congenital heart operations, ranging in complexity from isolated closure of a ventricular septal defect to single-ventricle palliation, at 40 tertiary-care pediatric centers in the Pediatric Health Information Systems database between 2007 and 2010. Assigned APR-DRGs (cardiac versus noncardiac) were compared using χ2 or Fisher's exact tests between those patients admitted during the first day of life versus later and between those receiving extracorporeal membrane oxygenation support versus those not. Recursive partitioning was used to assess the greatest determinants of APR-DRG type in the model.

RESULTS

Every patient admitted on day 1 of life was assigned to a noncardiac APR-DRG (p<0.001 for each procedure). Similarly, use of extracorporeal membrane oxygenation was highly associated with misclassification of CHS patients into a noncardiac APR-DRG (p<0.001 for each procedure). Cases misclassified into a noncardiac APR-DRG experienced a significantly increased mortality (p<0.001).

CONCLUSIONS

In classifying patients undergoing CHS, APR-DRG coding has systematic misclassifications, which may result in inaccurate reporting of CHS case volumes and mortality.