Table 5– Crude and adjusted hazard ratios (HRs) of in-hospital death according to the day of stay relative to weekdays for each of the first three weeks of hospitalisation, estimated by Poisson regression
DeathsPerson-daysRate per 1000 per dayCrude HRAdjusted# HR (95% CI)
First week
 Weekday (reference)2293473 2884.841.001.00 (reference)
 Friday1307228 2255.731.181.05 (0.98–1.12)
 Weekend3276516 2876.351.311.04 (0.98–1.10)
Second week
 Weekday (reference)6013869 3096.921.001.00 (reference)
 Friday1272153 5588.281.201.10 (1.03–1.17)
 Weekend2127241 8828.791.271.10 (1.03–1.17)
Third week
 Weekday (reference)3372370 6659.101.001.00 (reference)
 Friday70768 02010.391.141.08 (0.99–1.18)
 Weekend1241113 27110.961.201.10 (1.01–1.19)
  • #: for age, sex, calendar year of admission, 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, as well as time in hospital, as a time-dependent factor to control for the effect of the length of hospital stay; : Monday–Thursday of the week preceding the respective Friday and weekend.