Objective: To examine the effect of a weekend hospitalization on the timing and incidence of intensive cardiac procedures, and on subsequent expenditures, mortality and readmission rates for Medicare patients hospitalized with acute myocardial infarction (AMI).
Data sources: The primary data are longitudinal, administrative claims for 922,074 elderly, non-rural, fee-for-service Medicare beneficiaries hospitalized with AMI from 1989 to 1998. Annual patient-level cohorts provide information on ex ante health status, procedure use, expenditures, and health outcomes.
Study design: The patient is the primary unit of analysis. I use ordinary least squares regression to estimate the effect of weekend hospitalization on rates of cardiac catheterization, angioplasty, and bypass surgery (in various time periods subsequent to the initial hospitalization), 1-year expenditures and rates of adverse health outcomes in various periods following the AMI admission.
Principal findings: Weekend AMI patients are significantly less likely to receive immediate intensive cardiac procedures, and experience significantly higher rates of adverse health outcomes. Weekend admission leads to a 3.47 percentage point reduction in catheterization at 1 day, a 1.52 point reduction in angioplasty, and a 0.35 point reduction in by-pass surgery (p<.001 in all cases). The primary effect is delayed treatment, as weekend-weekday procedure differentials narrow over time from the initial hospitalization. Weekend patients experience a 0.38 percentage point (p<.001) increase in 1-year mortality and a 0.20 point (p<.001) increase in 1-year readmission with congestive heart failure.
Conclusions: Weekend hospitalization leads to delayed provision of intensive procedures and elevated 1-year mortality for elderly AMI patients. The existence of measurable differences in treatments raises questions regarding the efficacy of a single input regulation (e.g., mandated nurse staffing ratios) in enhancing the quality of weekend care. My results suggest that targeted financial incentives might be a more cost-effective policy response than broad regulation aimed at improving quality.