Association of hospital spending intensity with mortality and readmission rates in Ontario hospitals

Abstract

Context: The extent to which better spending produces higher-quality care and better patient outcomes in a universal health care system with selective access to medical technology is unknown.

Objective: To assess whether acute care patients admitted to higher-spending hospitals have lower mortality and readmissions.

Design, setting, and patients: The study population comprised adults (>18 years) in Ontario, Canada, with a first admission for acute myocardial infarction (AMI) (n = 179,139), congestive heart failure (CHF) (n = 92,377), hip fracture (n = 90,046), or colon cancer (n = 26,195) during 1998-2008, with follow-up to 1 year. The exposure measure was the index hospital's end-of-life expenditure index for hospital, physician, and emergency department services.

Main outcome measures: The primary outcomes were 30-day and 1-year mortality and readmissions and major cardiac events (readmissions for AMI, angina, CHF, or death) for AMI and CHF.

Results: Patients' baseline health status was similar across hospital expenditure groups. Patients admitted to hospitals in the highest- vs lowest-spending intensity terciles had lower rates of all adverse outcomes. In the highest- vs lowest-spending hospitals, respectively, the age- and sex-adjusted 30-day mortality rate was 12.7% vs 12.8% for AMI, 10.2% vs 12.4% for CHF, 7.7% vs 9.7% for hip fracture, and 3.3% vs 3.9% for CHF; fully adjusted relative 30-day mortality rates were 0.93 (95% CI, 0.89-0.98) for AMI, 0.81 (95% CI, 0.76-0.86) for CHF, 0.74 (95% CI, 0.68-0.80) for hip fracture, and 0.78 (95% CI, 0.66-0.91) for colon cancer. Results for 1-year mortality, readmissions, and major cardiac events were similar. Higher-spending hospitals had higher nursing staff ratios, and their patients received more inpatient medical specialist visits, interventional (AMI cohort) and medical (AMI and CHF cohorts) cardiac therapies, preoperative specialty care (colon cancer cohort), and postdischarge collaborative care with a cardiologist and primary care physician (AMI and CHF cohorts).

Conclusion: Among Ontario hospitals, higher spending intensity was associated with lower mortality, readmissions, and cardiac event rates.

Figure 1

Baseline Patient Severity, Measured as Predicted 30-Day Mortality Rate, Against Hospital Expenditure Index Group for the 4 Cohorts End-of-life expenditure index (EOL-EI) ranges, in US dollars, are <$29 970 for the low EOL-EI category, $29 970–$34 965 for the medium EOL-EI category, and >$34 965 for the high EOL-EI category. AMI indicates acute myocardial infarction; CHF, congestive heart failure. Error bars indicate 95% confidence intervals.

Figure 2

Multivariate Adjusted Relative 30-Day and 1-Year Mortality Rates for Medium and High vs Low Hospital Expenditure Groups for the 4 Cohorts End-of-life expenditure index (EOL-EI) ranges, in Canadian dollars, are <$30 000 (US $29 970) for the low EOL-EI category, $30 000 to $35 000 (US $29 970–$34 965) for the medium EOL-EI category, and >$35 000 (US $34 965) for the high EOL-EI category. AMI indicates acute myocardial infarction; CHF, congestive heart failure.

Figure 3

Multivariate Adjusted Relative 30-Day and 1-Year Cardiac (AMI, CHF) and All-Cause (Hip Fracture, Colon Cancer) Readmission Rates for Medium and High vs Low Hospital Expenditure Groups for the 4 Cohorts End-of-life expenditure index (EOL-EI) ranges, in Canadian dollars, are <$30 000 (US $29 970) for the low EOL-EI category, $30 000 to $35 000 (US $29 970–$34 965) for the medium EOL-EI category, and >$35 000 (US $34 965) for the high EOL-EI category. AMI indicates acute myocardial infarction; CHF, congestive heart failure.