Michael W. Sjoding

Association of Intensive Care Unit Admission With Mortality Among Older Patients With Pneumonia

IMPORTANCE Among patients whose need for intensive care is uncertain, the relationship of intensive care unit (ICU) admission with mortality and costs is unknown. OBJECTIVE To estimate the relationship between ICU admission and outcomes for elderly patients with pneumonia. DESIGN, SETTING, AND PATIENTS Retrospective cohort study of Medicare beneficiaries (aged >64 years) admitted to 2988 acute care hospitals in the United States with pneumonia from 2010 to 2012. EXPOSURES ICU admission vs general ward admission. MAIN OUTCOMES AND MEASURES Primary outcome was 30-day all-cause mortality. Secondary outcomes included Medicare spending and hospital costs. Patient and hospital characteristics were adjusted to account for differences between patients with and without ICU admission. To account for unmeasured confounding, an instrumental variable was used-the differential distance to a hospital with high ICU admission (defined as any hospital in the upper 2 quintiles of ICU use). RESULTS Among 1,112,394 Medicare beneficiaries with pneumonia, 328,404 (30%) were admitted to the ICU. In unadjusted analyses, patients admitted to the ICU had significantly higher 30-day mortality, Medicare spending, and hospital costs than patients admitted to a general hospital ward. Patients (n = 553,597) living closer than the median differential distance (<3.3 miles) to a hospital with high ICU admission were significantly more likely to be admitted to the ICU than patients living farther away (n = 558,797) (36% for patients living closer vs 23% for patients living farther, P < .001). In adjusted analyses, for the 13% of patients whose ICU admission decision appeared to be discretionary (dependent only on distance), ICU admission was associated with a significantly lower adjusted 30-day mortality (14.8% for ICU admission vs 20.5% for general ward admission, P = .02; absolute decrease, -5.7% [95% CI, -10.6%, -0.9%]), yet there were no significant differences in Medicare spending or hospital costs for the hospitalization. CONCLUSIONS AND RELEVANCE Among Medicare beneficiaries hospitalized with pneumonia, ICU admission of patients for whom the decision appeared to be discretionary was associated with improved survival and no significant difference in costs. A randomized trial may be warranted to assess whether more liberal ICU admission policies improve mortality for patients with pneumonia.

Longitudinal Changes in Icu Admissions Among Elderly Patients in the United States.

Objectives: Changes in population demographics and comorbid illness prevalence, improvements in medical care, and shifts in care delivery may be driving changes in the composition of patients admitted to the ICU. We sought to describe the changing demographics, diagnoses, and outcomes of patients admitted to critical care units in the U.S. hospitals. Design: Retrospective cohort study. Setting: U.S. hospitals. Patients: There were 27.8 million elderly (age, > 64 yr) fee-for-service Medicare beneficiaries hospitalized with an intensive care or coronary care room and board charge from 1996 to 2010. Interventions: None. Measurements and Main Results: We aggregated primary International Classification of Diseases, 9th Revision, Clinical Modification discharge diagnosis codes into diagnoses and disease categories. We examined trends in demographics, primary diagnosis, and outcomes among patients with critical care stays. Between 1996 and 2010, we found significant declines in patients with a primary diagnosis of cardiovascular disease, including coronary artery disease (26.6 to 12.6% of admissions) and congestive heart failure (8.5 to 5.4% of admissions). Patients with infectious diseases increased from 8.8% to 17.2% of admissions, and explicitly labeled sepsis moved from the 11th-ranked diagnosis in 1996 to the top-ranked primary discharge diagnosis in 2010. Crude in-hospital mortality rose (11.3 to 12.0%), whereas discharge destinations among survivors shifted, with an increase in discharges to hospice and postacute care facilities. Conclusions: Primary diagnoses of patients admitted to critical care units have substantially changed over 15 years. Funding agencies, physician accreditation groups, and quality improvement initiatives should ensure that their efforts account for the shifting epidemiology of critical illness.

Gaming hospital-level pneumonia 30-day mortality and readmission measures by legitimate changes to diagnostic coding

Objective: Risk-standardized 30-day mortality and hospital readmission rates for pneumonia are increasingly being tied to hospital reimbursement to incentivize the delivery of high-quality care. Such measures may be susceptible to gaming by recoding patients with pneumonia to a primary diagnosis of sepsis or respiratory failure. We sought to determine the degree to which hospitals can game mortality or readmission measures and change their rankings by recoding patients with pneumonia. Design and Setting: Simulated experimental study of 2,906 U.S. acute care hospitals with at least 25 admissions for pneumonia using 2009 Medicare data. Patients: Elderly (age ≥ 65 yr) Medicare fee-for-service beneficiaries hospitalized with pneumonia. Patients eligible for recoding to sepsis or respiratory failure were those with a principal International Classification of Diseases, 9th Edition, Clinical Modification, discharge code for pneumonia and secondary codes for respiratory failure or acute organ dysfunction. Interventions: None. Measurements and Main Results: We measured the number of hospitals that improved their pneumonia mortality or readmission rates after recoding eligible patients. When a sample of 100 hospitals with pneumonia mortality rates above the 50th percentile recoded all eligible patients to sepsis or respiratory failure, 90 hospitals (95% CI, 84–95) improved their mortality rate (mean improvement, 1.09%; 95% CI, 0.94–1.28%) and 41 hospitals dropped below the 50th percentile (95% CI, 33–52). When a sample of 100 hospitals with pneumonia readmission rates above the 50th percentile recoded all eligible patients, 66 hospitals (95% CI, 54–75) improved their readmission rate (mean improvement, 0.34%; 95% CI, 0.19–0.45%) and 15 hospitals (95% CI, 9–22) dropped below the 50th percentile. Conclusions: Hospitals can improve apparent pneumonia mortality and readmission rates by recoding pneumonia patients. Centers for Medicare and Medicaid Services should consider changes to their methods used to calculate hospital-level pneumonia outcome measures to make them less susceptible to gaming.

When do confounding by indication and inadequate risk adjustment bias critical care studies? A simulation study

IntroductionIn critical care observational studies, when clinicians administer different treatments to sicker patients, any treatment comparisons will be confounded by differences in severity of illness between patients. We sought to investigate the extent that observational studies assessing treatments are at risk of incorrectly concluding such treatments are ineffective or even harmful due to inadequate risk adjustment.MethodsWe performed Monte Carlo simulations of observational studies evaluating the effect of a hypothetical treatment on mortality in critically ill patients. We set the treatment to have either no association with mortality or to have a truly beneficial effect, but more often administered to sicker patients. We varied the strength of the treatment’s true effect, strength of confounding, study size, patient population, and accuracy of the severity of illness risk-adjustment (area under the receiver operator characteristics curve, AUROC). We measured rates in which studies made inaccurate conclusions about the treatment’s true effect due to confounding, and the measured odds ratios for mortality for such false associations.ResultsSimulated observational studies employing adequate risk-adjustment were generally able to measure a treatment’s true effect. As risk-adjustment worsened, rates of studies incorrectly concluding the treatment provided no benefit or harm increased, especially when sample size was large (n = 10,000). Even in scenarios of only low confounding, studies using the lower accuracy risk-adjustors (AUROC < 0.66) falsely concluded that a beneficial treatment was harmful. Measured odds ratios for mortality of 1.4 or higher were possible when the treatment’s true beneficial effect was an odds ratio for mortality of 0.6 or 0.8.ConclusionsLarge observational studies confounded by severity of illness have a high likelihood of obtaining incorrect results even after employing conventionally “acceptable” levels of risk-adjustment, with large effect sizes that may be construed as true associations. Reporting the AUROC of the risk-adjustment used in the analysis may facilitate an evaluation of a study’s risk for confounding.

Rising Billing for Intermediate Intensive Care among Hospitalized Medicare Beneficiaries between 1996 and 2010

RATIONALE Intermediate care (i.e., step-down or progressive care) is an alternative to the intensive care unit (ICU) for patients with moderate severity of illness. The adoption and current use of intermediate care is unknown. OBJECTIVES To characterize trends in intermediate care use among U.S. hospitals. METHODS We examined 135 million acute care hospitalizations among elderly individuals (≥65 yr) enrolled in fee-for-service Medicare (U.S. federal health insurance program) from 1996 to 2010. We identified patients receiving intermediate care as those with intensive care or coronary care room and board charges labeled intermediate ICU. MEASUREMENTS AND MAIN RESULTS In 1996, a total of 960 of the 3,425 hospitals providing critical care billed for intermediate care (28%), and this increased to 1,643 of 2,783 hospitals (59%) in 2010 (P < 0.01). Only 8.2% of Medicare hospitalizations in 1996 were billed for intermediate care, but billing steadily increased to 22.8% by 2010 (P < 0.01), whereas the percentage billed for ICU care and ward-only care declined. Patients billed for intermediate care had more acute organ failures diagnoses codes compared with general ward patients (22.4% vs. 15.8%). When compared with patients billed for ICU care, those billed for intermediate care had fewer organ failures (22.4% vs. 43.4%), less mechanical ventilation (0.9% vs. 16.7%), lower mean Medicare spending (

Acute Respiratory Distress Syndrome Measurement Error. Potential Effect on Clinical Study Results

8,514 vs.

Hospitals with the Highest Intensive Care Utilization Provide Lower Quality Pneumonia Care to the Elderly

18,150), and lower 30-day mortality (5.6% vs. 16.5%) (P < 0.01 for all comparisons). CONCLUSIONS Intermediate care billing increased markedly between 1996 and 2010. These findings highlight the need to better define the value, specific practices, and effective use of intermediate care for patients and hospitals.

Changes in Primary Noncardiac Diagnoses Over Time Among Elderly Cardiac Intensive Care Unit Patients in the United States

RATIONALE Identifying patients with acute respiratory distress syndrome (ARDS) is a recognized challenge. Experts often have only moderate agreement when applying the clinical definition of ARDS to patients. However, no study has fully examined the implications of low reliability measurement of ARDS on clinical studies. OBJECTIVES To investigate how the degree of variability in ARDS measurement commonly reported in clinical studies affects study power, the accuracy of treatment effect estimates, and the measured strength of risk factor associations. METHODS We examined the effect of ARDS measurement error in randomized clinical trials (RCTs) of ARDS-specific treatments and cohort studies using simulations. We varied the reliability of ARDS diagnosis, quantified as the interobserver reliability (κ-statistic) between two reviewers. In RCT simulations, patients identified as having ARDS were enrolled, and when measurement error was present, patients without ARDS could be enrolled. In cohort studies, risk factors as potential predictors were analyzed using reviewer-identified ARDS as the outcome variable. MEASUREMENTS AND MAIN RESULTS Lower reliability measurement of ARDS during patient enrollment in RCTs seriously degraded study power. Holding effect size constant, the sample size necessary to attain adequate statistical power increased by more than 50% as reliability declined, although the result was sensitive to ARDS prevalence. In a 1,400-patient clinical trial, the sample size necessary to maintain similar statistical power increased to over 1,900 when reliability declined from perfect to substantial (κ = 0.72). Lower reliability measurement diminished the apparent effectiveness of an ARDS-specific treatment from a 15.2% (95% confidence interval, 9.4-20.9%) absolute risk reduction in mortality to 10.9% (95% confidence interval, 4.7-16.2%) when reliability declined to moderate (κ = 0.51). In cohort studies, the effect on risk factor associations was similar. CONCLUSIONS ARDS measurement error can seriously degrade statistical power and effect size estimates of clinical studies. The reliability of ARDS measurement warrants careful attention in future ARDS clinical studies.

Chronic critical illness: a growing legacy of successful advances in critical care

Objective:Quality of care for patients admitted with pneumonia varies across hospitals, but causes of this variation are poorly understood. Whether hospitals with high ICU utilization for patients with pneumonia provide better quality care is unknown. We sought to investigate the relationship between a hospital’s ICU admission rate for elderly patients with pneumonia and the quality of care it provided to patients with pneumonia. Design:Retrospective cohort study. Setting:Two thousand eight hundred twelve U.S. hospitals. Patients:Elderly (age ≥ 65 years) fee-for-service Medicare beneficiaries with either a (1) principal diagnosis of pneumonia or (2) principal diagnosis of sepsis or respiratory failure and secondary diagnosis of pneumonia in 2008. Interventions:None. Measurements and Main Results:We grouped hospitals into quintiles based on ICU admission rates for pneumonia. We compared rates of failure to deliver pneumonia processes of care (calculated as 100 – adherence rate), 30-day mortality, hospital readmissions, and Medicare spending across hospital quintile. After controlling for other hospital characteristics, hospitals in the highest quintile more often failed to deliver pneumonia process measures, including appropriate initial antibiotics (13.0% vs 10.7%; p < 0.001), and pneumococcal vaccination (15.0% vs 13.3%; p = 0.03) compared with hospitals in quintiles 1–4. Hospitals in the highest quintile of ICU admission rate for pneumonia also had higher 30-day mortality, 30-day hospital readmission rates, and hospital spending per patient than other hospitals. Conclusions:Quality of care was lower among hospitals with the highest rates of ICU admission for elderly patients with pneumonia; such hospitals were less likely to deliver pneumonia processes of care and had worse outcomes for patients with pneumonia. High pneumonia-specific ICU admission rates for elderly patients identify a group of hospitals that may deliver inefficient and poor-quality pneumonia care and may benefit from interventions to improve care delivery.

Intensive Care Unit Admission and Survival among Older Patients with Chronic Obstructive Pulmonary Disease, Heart Failure, or Myocardial Infarction

Background— Early reports suggest the number of cardiac intensive care unit (CICU) patients with primary noncardiac diagnoses is rising in the United States, but no national data currently exist. We examined changes in primary noncardiac diagnoses among elderly patients admitted to a CICU during the past decade. Methods and Results— Using 2003 to 2013 Medicare data, we grouped elderly patients admitted to CICUs into 2 categories based on principal diagnosis at discharge: (1) primary noncardiac diagnoses and (2) primary cardiac diagnoses. We examined changes in patient demographics, comorbidities, procedure use, and risk-adjusted in-hospital mortality. Among 3.4 million admissions with a CICU stay, primary noncardiac diagnoses rose in prevalence from 38.0% to 51.7% between 2003 and 2013. The fastest rising primary noncardiac diagnoses were infectious diseases (7.8%–15.1%) and respiratory diseases (6.0%–7.6%; P<0.001 for both), whereas the fastest declining primary cardiac diagnosis was coronary artery disease (32.3%–19.0%; P<0.001). Simultaneously, the prevalence of both cardiovascular and noncardiovascular comorbidities rose: heart failure (13.9%–34.4%), pulmonary vascular disease (1.2%–7.1%), valvular heart disease (5.0%–9.8%), and renal failure (7.1%–19.6%; P<0.001 for all). As compared with those with primary cardiac diagnoses, elderly CICU patients with primary noncardiac diagnoses had higher rates of noncardiac procedure use and risk-adjusted in-hospital mortality (P<0.001 for all). Risk-adjusted in-hospital mortality declined slightly in the overall cohort from 9.3% to 8.9% (P<0.001). Conclusions— More than half of all elderly patients with a CICU stay across the United States now have primary noncardiac diagnoses at discharge. These patients receive different types of care and have worse outcomes than patients with primary cardiac diagnoses. Our work has important implications for the development of appropriate training and staffing models for the future critical care workforce.