Table 4.
Rate ratios for duration of first admission, total number of hospital days and number of readmissions during the 34 years of follow-upa
| Events, n | Person-years | Crude rate ratio (95% CI) | Adjusted rate ratio (95% CI)b | |
|---|---|---|---|---|
| Duration of first hospital episode | ||||
| Never used cannabis | 25 305 | 5812 | 1 | 1 |
| Ever used cannabis | 9296 | 1460 | 1.4 (1.3–1.5) | 1.4 (1.1–2.8) |
| Number of readmissions | ||||
| Never used cannabis | 2332 | 3665 | 1 | 1 |
| Ever used cannabis | 955 | 1005 | 1.5 (1.3–1.6) | 1.3 (1.1–1.8) |
| Total number of hospital days | ||||
| Never used cannabis | 154 300 | 5382 | 1 | 1 |
| Ever used cannabis | 52 426 | 1207 | 1.5 (1.4–1.6) | 1.5 (1.1–2.4) |
CI, Confidence interval.
a
Rate ratios were calculated by using negative binomial regression.
b
Adjusting for age at first admission for schizophrenia.