Table 4– Crude and adjusted rate ratios (RRs) of in-hospital death according to the day of stay, relative to weekdays#, stratified by diagnosis, sex and year of admission time
Friday stayWeekend stay
Crude RRAdjusted RR (95% CI)Crude RRAdjusted RR (95% CI)
Hospitalisation diagnosis
 COPD1.051.06 (1.01–1.10)1.091.09 (1.05–1.13)
 Pneumonia1.041.04 (1.00–1.09)1.041.04 (1.00–1.08)
 Male1.071.07 (1.03–1.12)1.081.08 (1.05–1.12)
 Female1.011.02 (0.97–1.07)1.041.04 (1.00–1.08)
Calendar year of admission
 1990–19951.081.08 (1.02–1.15)1.071.07 (1.02–1.12)
 1996–20001.021.02 (0.96–1.08)1.061.05 (1.01–1.10)
 2001–20071.051.05 (1.01–1.11)1.081.07 (1.03–1.12)
  • COPD: chronic obstructive pulmonary disease. #: Monday–Thursday inclusive; : for age, sex, calendar year of admission, admission day (weekday, Friday or weekend), prior hospitalisation and the modified chronic disease score divided into quartiles with a fifth category to account for subjects with no medication information in the year prior to cohort entry.