The Relative Ability of Comorbidity Ascertainment Methodologies to Predict In-Hospital Mortality Among Hospitalized Community-acquired Pneumonia Patients

The Impact of Principal Diagnosis on Readmission Risk among Patients Hospitalized for Community-Acquired Pneumonia

Coding variation distorts performance/outcome statistics not eliminated by risk adjustment. Among 1596 community-acquired pneumonia patients hospitalized from 1998 to 2012 identified using an evidence-based algorithm, the authors measured the association of principal diagnosis (PD) with 30-day readmission, stratified by Pneumonia Severity Index risk class. The 152 readmitted patients were more ill (Pneumonia Severity Index class V 38.8% versus 25.8%) and less likely to have a pneumonia PD (52.6% versus 69.9%). Among patients with PDs of pneumonia, respiratory failure, sepsis, and aspiration, mortality/readmission rates were 3.9/8.5%, 28.8/14.0%, 24.7/19.6%, and 9.0/15.0%, respectively. The nonpneumonia PDs were associated with a greater risk of adjusted 30-day readmission: respiratory failure odds ratio (OR) 1.89 (95% confidence interval [CI], 1.13-3.15), sepsis OR 2.54 (95% CI, 1.52-4.26), and possibly aspiration OR 1.73 (95% CI, 0.88-3.41). With increasing use of alternative PDs among pneumonia patients, quality reporting must account for variations in condition coding practices. Rigorous risk adjustment does not eliminate the need for accurate, consistent case definition in producing valid quality measures.

Prevalence and Outcomes of Previously Healthy Adults Among Patients Hospitalized With Community-Onset Sepsis

BACKGROUND

Devastating cases of sepsis in previously healthy patients have received widespread attention and have helped to catalyze state and national mandates to improve sepsis detection and care. However, it is unclear what proportion of patients hospitalized with sepsis previously were healthy and how their outcomes compare with those of patients with comorbidities.

RESEARCH QUESTION

Among adults hospitalized with community-onset sepsis, how many previously were healthy and how do their outcomes compare with those of patients with comorbidities?

STUDY DESIGN AND METHODS

We retrospectively identified all adults with community-onset sepsis hospitalized in 373 US hospitals from 2009 through 2015 using clinical indicators of presumed infection and organ dysfunction (Centers for Disease Control and Prevention's Adult Sepsis Event criteria). Comorbidities were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. We applied generalized linear mixed models to measure the associations between the presence or absence of comorbidities and short-term mortality (in-hospital death or discharge to hospice), adjusting for severity of illness on admission.

RESULTS

Of 6,715,286 hospitalized patients, 337,983 (5.0%) were hospitalized with community-onset sepsis. Most patients with sepsis (329,052 [97.4%]) had received a diagnosis of at least one comorbidity; only 2.6% previously were healthy. Patients with sepsis who previously were healthy were younger than those with comorbidities (mean age, 58.0 ± 19.8 years vs 67.0 ± 16.5 years), were less likely to require ICU care on admission (37.9% vs 50.5%), and were more likely to be discharged home (57.9% vs 45.6%), rather than to subacute facilities (16.3% vs 30.8%), but showed higher short-term mortality rates (22.8% vs 20.8%; P < .001 for all). The association between previously healthy status and higher short-term mortality persisted after risk adjustment (adjusted OR, 1.99; 95% CI, 1.87-2.13).

INTERPRETATION

The vast majority of patients hospitalized with community-onset sepsis harbor pre-existing comorbidities. However, previously healthy patients may be more likely to die when they seek treatment at the hospital with sepsis compared with patients with comorbidities. These findings underscore the importance of early sepsis recognition and treatment for all patients.

Early Reoperation Rates and Its Risk Factors after Instrumented Spinal Fusion Surgery for Degenerative Spinal Disease: A Nationwide Cohort Study of 65,355 Patients

Reoperation is a major concern in spinal fusion surgery for degenerative spinal disease. Earlier reported reoperation rates were confined to a specific spinal region without comprehensive analysis, and their prediction models for reoperation were not statistically validated. Our study aimed to present reasonable base rates for reoperation according to all possible risk factors and build a validated prediction model for early reoperation. In our nationwide population-based cohort study, data between 2014 and 2016 were obtained from the Korean National Health Insurance claims database. Patients older than 19 years who underwent instrumented spinal fusion surgery for degenerative spinal diseases were included. The patients were divided into cases (patients who underwent reoperation) and controls (patients who did not undergo reoperation), and risk factors for reoperation were determined by multivariable analysis. The estimates of all statistical models were internally validated using bootstrap samples, and sensitivity analyses were additionally performed to validate the estimates by comparing the two prediction models (models for 1st-year and 3rd-year reoperation). The study included 65,355 patients: 2939 (4.5%) who underwent reoperation within 3 years after the index surgery and 62,146 controls. Reoperation rates were significantly different according to the type of surgical approach and the spinal region. The third-year reoperation rates were 5.3% in the combined lumbar approach, 5.2% in the posterior lumbar approach, 5.0% in the anterior lumbar approach, 3.0% in the posterior thoracic approach, 2.8% in the posterior cervical approach, 2.6% in the anterior cervical approach, and 1.6% in the combined cervical approach. Multivariable analysis identified older age, male sex, hospital type, comorbidities, allogeneic transfusion, longer use of steroids, cages, and types of surgical approaches as risk factors for reoperation. Clinicians can conduct comprehensive risk assessment of early reoperation in patients who will undergo instrumented spinal fusion surgery for degenerative spinal disease using this model.

All Patient Refined-Diagnosis Related Groups' (APR-DRGs) Severity of Illness and Risk of Mortality as predictors of in-hospital mortality

The aims of this study were to assess All-Patient Refined Diagnosis-Related Groups' (APR-DRG) Severity of Illness (SOI) and Risk of Mortality (ROM) as predictors of in-hospital mortality, comparing with Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI) scores. We performed a retrospective observational study using mainland Portuguese public hospitalizations of adult patients from 2011 to 2016. Model discrimination (C-statistic/ area under the curve) and goodness-of-fit (R-squared) were calculated. Our results comprised 4,176,142 hospitalizations with 5.9% in-hospital deaths. Compared to the CCI and ECI models, the model considering SOI, age and sex showed a statistically significantly higher discrimination in 49.6% (132 out of 266) of APR-DRGs, while in the model with ROM that happened in 33.5% of APR-DRGs. Between these two models, SOI was the best performer for nearly 20% of APR-DRGs. Some particular APR-DRGs have showed good discrimination (e.g. related to burns, viral meningitis or specific transplants). In conclusion, SOI or ROM, combined with age and sex, perform better than more widely used comorbidity indices. Despite ROM being the only score specifically designed for in-hospital mortality prediction, SOI performed better. These findings can be helpful for hospital or organizational models benchmarking or epidemiological analysis.

Underlying Medical Conditions and Severe Illness Among 540,667 Adults Hospitalized With COVID-19, March 2020-March 2021

INTRODUCTION

Severe COVID-19 illness in adults has been linked to underlying medical conditions. This study identified frequent underlying conditions and their attributable risk of severe COVID-19 illness.

METHODS

We used data from more than 800 US hospitals in the Premier Healthcare Database Special COVID-19 Release (PHD-SR) to describe hospitalized patients aged 18 years or older with COVID-19 from March 2020 through March 2021. We used multivariable generalized linear models to estimate adjusted risk of intensive care unit admission, invasive mechanical ventilation, and death associated with frequent conditions and total number of conditions.

RESULTS

Among 4,899,447 hospitalized adults in PHD-SR, 540,667 (11.0%) were patients with COVID-19, of whom 94.9% had at least 1 underlying medical condition. Essential hypertension (50.4%), disorders of lipid metabolism (49.4%), and obesity (33.0%) were the most common. The strongest risk factors for death were obesity (adjusted risk ratio [aRR] = 1.30; 95% CI, 1.27-1.33), anxiety and fear-related disorders (aRR = 1.28; 95% CI, 1.25-1.31), and diabetes with complication (aRR = 1.26; 95% CI, 1.24-1.28), as well as the total number of conditions, with aRRs of death ranging from 1.53 (95% CI, 1.41-1.67) for patients with 1 condition to 3.82 (95% CI, 3.45-4.23) for patients with more than 10 conditions (compared with patients with no conditions).

CONCLUSION

Certain underlying conditions and the number of conditions were associated with severe COVID-19 illness. Hypertension and disorders of lipid metabolism were the most frequent, whereas obesity, diabetes with complication, and anxiety disorders were the strongest risk factors for severe COVID-19 illness. Careful evaluation and management of underlying conditions among patients with COVID-19 can help stratify risk for severe illness.

Differences in the Predictive value of Elixhauser Comorbidity Index and the Charlson Comorbidity indices in patients with hand infections

PURPOSE

Hand infections are a common source of potentially debilitating morbidity, particularly in patients with comorbid disease. We hypothesize that there is a difference in predictive value between two commonly used comorbidity indices for the prognosis of hand infections, which may have clinical implications in the management of these conditions.

METHODS

The Nationwide Inpatient Sample 2001-2013 database was queried for hand infections using International Classification of Diseases, Ninth Revision codes. The Elixhauser (ECI) and Charlson (CCI) comorbidity scores were calculated based on validated sets of ICD-9 codes. Primary outcomes included mortality, prolonged length of stay (LOS, defined as >95 percentile), discharge destination, and postoperative complications. Indices were compared using receiver operating characteristic (ROC) curves and the areas under the curve (AUC). If confidence intervals overlapped, significance was determined using the DeLong method for correlated ROC curves. This is a validated, non-parametric comparison used for the calculation of the difference between two AUCs.

RESULTS

A weighted total of 1,511,057 patients were included in this study. The majority were Caucasian (57.1%) males (61.4%). Complication rates included 0.9% mortality, 5.3% prolonged length of stay, 25.3% discharges to non-home destinations, and 5.3% post-operative complications. The ECI and CCI each demonstrated good predictive value for mortality, but poor predictive value for non-routine discharge, prolonged LOS, and post-operative complications. There was a significantly increased likelihood of each complication with increasing comorbidity score for both indices, with the greatest odds ratio in the ECI ≥4 cohort.

CONCLUSIONS

The CCI was superior in predicting mortality while the ECI was superior in predicting non-routine discharge, prolonged length of stay, and postoperative complications, but these indices may not be clinically relevant. While both represent good predictive models, a score specifically designed for patients with hand infections may have superior prognostic value.

LEVEL OF EVIDENCE

Level IV.