A cohort study of people who were admitted to hospital for a stroke looked at the association between admission to hospital on weekdays (Monday to Friday) or the weekend (Saturday and Sunday) with in-hospital mortality. The data from the study are reported in Table 1 below. In this question, provide all working for your calculations.
Table 1: In hospital mortality, by admission period (weekday or weekend), among people admitted to hospital for a stroke:
Deaths
Number of people admitted
Weekend admission
2467
23297
Weekend admission
5929
70324
Total
8396
93621
Now calculate and interpret the population attributable fraction for weekend admissions.
What further information would you wish to know to assess the validity of your conclusions?