Clinical question: Do hospitals caring for a higher volume of patients with congestive heart failure (CHF) provide better, more efficient care for those patients?
Background: For some surgical and cardiovascular procedures, higher procedure volumes have been associated with better outcomes and lower costs. It is unclear whether this association also exists for common medical conditions, such as CHF.
Study design: Retrospective cohort study.
Setting: National sample of Medicare fee-for-service patients 65 years or older.
Synopsis: National Medicare claims data for more than 1 million discharges from 4,095 hospitals were used to examine the relationship between hospital case volume and quality of care, outcomes, and cost for patients with CHF. Quality of care was defined using the Hospital Quality Alliance (HQA) data on four clinical process measures for CHF from 2007. Hospitals were grouped based on their number of CHF discharges during two years: low volume (25-200), medium volume (201-400), and high volume (>400). Risk adjustment was performed.
Hospitals in the low-volume group had lower performance on the process measures (80.2%) than did medium-volume (87.0%) or high-volume (89.1%) hospitals (P<0.001). Thirty-day mortality was highest in low-volume hospitals (10.2%), when compared to medium-volume (9.3%) and high-volume (8.6%) hospitals (P<0.001). Hospital costs were higher at high-volume hospitals ($8,300) than at medium-volume ($7,700) and low-volume ($7,300) hospitals (P<0.001). Readmission rates were not statistically different between hospital groups.
The relationship between volume and outcomes in the study was not linear, and the incremental benefits seen were small beyond the volume of patients seen at medium-volume hospitals.
Bottom line: Hospitals with higher volumes of CHF patients have better CHF process-of-care measures and lower 30-day CHF mortality but also higher CHF costs.
Citation: Joynt KE, Orav EJ, Jha AK. The association between hospital volume and processes, outcomes, and costs of care for congestive heart failure. Ann Intern Med. 2011;154(2):94-102.
For more physician reviews of HM-related research, visit our website.