Figure 2
Calculation of waiting time to hospitalization in four situations. I. Patients with no hospitalization with a complete set of observations after t 1, where t 1 is 21 days after the first service date. II. Patients with hospitalization with a complete set of observations in the first hospitalization interval [ t 1,t 2], where t 1 is 21 days after the first service date and t 2 is 21 days before the first hospitalization. III. Patients with hospitalization who had their first complete set of observation in the k thhospitalization interval [ t 1k ,t 2k ], where t 1k is 21 days after the k thhospitalization and t 2k is 21 days before the (k+1)thhospitalization. IV. Patients with hospitalization who had their first complete set of observation in the last hospitalization interval [ t 1l ,t 2l ], where t 1l is 21 days after the last hospitalization and t 2l is the last service date.