Table 5.
Hazard ratios (95% confidence interval) for age adjusted associations between defined daily doses (DDDs) of study drug (versus no study drugs) and mortality before and after adjusting for other potential confounders*, for exposure restricted to receipt of study drugs in first year after recruitment only
| DDDs | No of patients | Age adjusted hazard ratio (95% CI) | P value | Fully adjusted* hazard ratio (95% CI) | P value |
|---|---|---|---|---|---|
| All study drugs: | |||||
| 0 | 69 418 | 1.00 | — | 1.00 | — |
| 1-30 | 6648 | 2.47 (2.34 to 2.60) | <0.001 | 2.55 (2.42 to 2.69) | <0.001 |
| 31-60 | 2859 | 3.87 (3.66 to 4.15) | <0.001 | 3.78 (3.54 to 4.04) | <0.001 |
| 61-90 | 1185 | 5.04 (4.62 to 5.50) | <0.001 | 4.19 (3.84 to 4.58) | <0.001 |
| ≥91 | 1971 | 5.59 (5.21 to 5.92) | <0.001 | 4.51 (4.22 to 4.82) | <0.001 |
| Any DDDs | 12 663 | 3.46 (3.34 to 3.59) | <0.001 | 3.32 (3.19 to 3.45) | <0.001 |
| Benzodiazepines only: | |||||
| 1-30 | 4625 | 2.71 (2.54 to 2.88) | <0.001 | 2.78 (2.62 to 2.96) | <0.001 |
| 31-60 | 1414 | 5.17 (4.77 to 5.59) | <0.001 | 4.62 (4.26 to 5.01) | <0.001 |
| 61-90 | 549 | 6.62 (5.91 to 7.42) | <0.001 | 5.42 (4.84 to 6.08) | <0.001 |
| ≥91 | 881 | 6.75 (6.18 to 7.34) | <0.001 | 5.10 (4.67 to 5.58) | <0.001 |
| Any DDDs | 7469 | 3.89 (3.73 to 4.06) | <0.001 | 3.68 (3.52 to 3.85) | <0.001 |
| Z drugs only: | |||||
| 1-30 | 858 | 2.39 (2.07 to 2.77) | <0.001 | 2.36 (2.05 to 2.74) | <0.001 |
| 31-60 | 807 | 3.53 (3.08 to 4.04) | <0.001 | 3.41 (2.98 to 3.91) | <0.001 |
| 61-90 | 278 | 4.58 (3.75 to 5.59) | <0.001 | 3.66 (2.99 to 4.48) | <0.001 |
| ≥91 | 492 | 4.83 (4.22 to 5.54) | <0.001 | 3.90 (3.39 to 4.47) | <0.001 |
| Any DDDs | 2435 | 3.50 (3.24 to 3.77) | <0.001 | 3.19 (2.95 to 3.45) | <0.001 |
| Other study drugs only: | |||||
| 1-30 | 976 | 1.93 (1.71 to 2.19) | <0.001 | 1.86 (1.64 to 2.10) | <0.001 |
| 31-60 | 378 | 2.02 (1.67 to 2.43) | <0.001 | 2.09 (1.73 to 2.51) | <0.001 |
| 61-90 | 154 | 2.92 (2.25 to 3.82) | <0.001 | 2.46 (1.87 to 3.22) | <0.001 |
| ≥91 | 175 | 3.34 (2.68 to 4.16) | <0.001 | 2.65 (2.13 to 3.30) | <0.001 |
| Any DDDs | 1683 | 2.18 (2.00 to 2.38) | <0.001 | 2.06 (1.88 to 2.25) | <0.001 |
*Age, sex, physical health problems (arthritis, asthma, cancer, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, diabetes, epilepsy, gastrointestinal disorders, hypertension, musculoskeletal disorders, anxiety disorders, sleep disorders, other (non-anxiety), psychiatric disorders, and prescriptions for non-study drugs.