Associations of physician volume and weekend admissions with ischemic stroke outcome in Taiwan: a nationwide population-based study.

Background: Although volume-outcome and weekend-outcome relationships have been explored for various procedures and interventions, limited information is available concerning "physician volume" and the "weekend effect" on stroke mortality. Moreover, little is known about the relative and combined influence of physician and hospital volume on stroke mortality.

Objectives: We used nationwide population-based data to explore the influences of physician volume and weekend admissions on stroke mortality.

Methods: We analyzed all 34,347 ischemic stroke patients admitted in 2005, treated by 2424 physicians practicing in 245 hospitals in Taiwan through Taiwan's National Health Insurance Research Database. Multilevel logistic regression analysis was performed after adjustment for patient, physician, and hospital characteristics to explore the individual and combined impact of annual physician volume and annual hospital volume, as well as the impact of weekend admissions, on 30-day mortality.

Results: Higher physician volume, simultaneous contribution of higher physician and higher hospital volume, and weekday admissions were associated with decreased 30-day mortality, after adjusting for patient gender and age, comorbidities, surgery, physician age and specialty, hospital ownership, accreditation level, teaching status, geographic location, regional resources, and competition.

Conclusions: Higher physician volume, rather than higher hospital volume is associated with lower 30-day ischemic stroke mortality, but the relationship has become stronger in higher-volume hospitals. Stroke patients admitted on weekends also have a higher mortality than those admitted on weekdays.