Hospital spending and inpatient mortality: evidence from California: an observational study

Abstract

Background: Evidence shows that high Medicare spending is not associated with better health outcomes at a regional level and that high spending in hospitals is not associated with better process quality. The relationship between hospital spending and inpatient mortality is less well understood.

Objective: To determine the association between hospital spending and risk-adjusted inpatient mortality.

Design: Retrospective cohort study.

Setting: Database of discharge records from 1999 to 2008 for 208 California hospitals included in The Dartmouth Atlas of Health Care.

Patients: 2 545 352 patients hospitalized during 1999 to 2008 with 1 of 6 major medical conditions.

Measurements: Inpatient mortality rates among patients admitted to hospitals with varying levels of end-of-life hospital spending.

Results: For each of 6 diagnoses at admission-acute myocardial infarction, congestive heart failure, acute stroke, gastrointestinal hemorrhage, hip fracture, and pneumonia-patient admission to hig her-spending hospitals was associated with lower risk-adjusted inpatient mortality. During 1999 to 2003, for example, patients admitted with acute myocardial infarction to California hospitals in the highest quintile of hospital spending had lower inpatient mortality than did those admitted to hospitals in the lowest quintile (odds ratio, 0.862 [95% CI, 0.742 to 0.983]). Predicted inpatient deaths would increase by 1831 if all patients admitted with acute myocardial infarction were cared for in hospitals in the lowest quintile of spending rather than the highest. The association between hospital spending and inpatient mortality did not vary by region or hospital size.

Limitation: Unobserved predictors of mortality create uncertainty about whether greater inpatient hospital spending leads to lower inpatient mortality.

Conclusion: Hospitals that spend more have lower inpatient mortality for 6 common medical conditions.

Appendix Figure 1

Risk-adjusted odds-ratio of inpatient mortality by hospital spending quintile for six major medical conditions, 1999–2003 and 2004–2008 Notes: Odds ratios of inpatient mortality for a given hospital spending quintile are calculated with respect to the lowest quintile. Vertical bars represent 95% confidence intervals around the predicted lives saved (boxes).Abbreviations: Acute myocardial infarction (AMI), congestive heart failure (CHF), gastrointestinal hemorrhage (GI bleed).

Figure 1. Predicted lives saved if all patients were treated in hospitals in the top spending quintile vs. the bottom spending quintile

Notes: Vertical bars represent 95% confidence intervals around the predicted lives saved (boxes). Abbreviations: Acute myocardial infarction (AMI), congestive heart failure (CHF), gastrointestinal hemorrhage (GI bleed).