Table 6.
Hazard ratios (95% confidence intervals) for age adjusted associations between defined daily doses (DDDs) of study drug and mortality before and after adjusting for other potential confounders, for exposure restricted to receipt of study drugs in first year after recruitment only and for patients with at least 12 months of follow-up
| DDDs | No of patients | Age adjusted hazard ratio (95% CI) | P value | Fully adjusted* hazard ratio (95% CI) | P value |
|---|---|---|---|---|---|
| All study drugs: | |||||
| 0 | 63 717 | 1.00 | — | 1.00 | — |
| 1-30 | 5142 | 1.46 (1.35 to 1.57) | <0.001 | 1.45 (1.35 to 1.56) | <0.001 |
| 31-60 | 1873 | 2.02 (1.82 to 2.23) | <0.001 | 1.94 (1.76 to 2.16) | <0.001 |
| 61-90 | 659 | 2.27 (1.94 to 2.66) | <0.001 | 1.87 (1.59 to 2.19) | <0.001 |
| ≥91 | 910 | 3.14 (2.80 to 3.52) | <0.001 | 2.63 (2.34 to 2.95) | <0.001 |
| Any DDDs | 8584 | 1.83 (1.73 to 1.92) | <0.001 | 1.75 (1.65 to 1.85) | <0.001 |
| Benzodiazepines only: | |||||
| 1-30 | 3561 | 1.46 (1.33 to 1.59) | <0.001 | 1.47 (1.34 to 1.61) | <0.001 |
| 31-60 | 791 | 2.31 (2.01 to 2.65) | <0.001 | 2.07 (1.80 to 2.38) | <0.001 |
| 61-90 | 251 | 2.63 (2.09 to 3.32) | <0.001 | 2.31 (1.84 to 2.92) | <0.001 |
| ≥91 | 361 | 4.14 (3.53 to 4.87) | <0.001 | 3.32 (2.83 to 3.89) | <0.001 |
| Any DDDs | 4964 | 1.88 (1.76 to 2.02) | <0.001 | 1.81 (1.68 to 1.94) | <0.001 |
| Z drugs only: | |||||
| 1-30 | 655 | 1.39 (1.12 to 1.71) | <0.001 | 1.34 (1.08 to 1.66) | <0.001 |
| 31-60 | 603 | 2.05 (1.67 to 2.51) | <0.001 | 2.05 (1.67 to 2.51) | <0.001 |
| 61-90 | 186 | 2.43 (1.76 to 3.36) | <0.001 | 1.81 (1.31 to 2.51) | <0.001 |
| ≥91 | 271 | 2.7 (2.15 to 3.39) | <0.001 | 2.25 (1.79 to 2.84) | <0.001 |
| Any DDDs | 1715 | 1.94 (1.72 to 2.17) | <0.001 | 1.78 (1.58 to 2.01) | <0.001 |
| Other study drugs only: | |||||
| 1-30 | 785 | 1.5 (1.28 to 1.75) | <0.001 | 1.45 (1.24 to 1.69) | <0.001 |
| 31-60 | 310 | 1.58 (1.26 to 2.01) | <0.001 | 1.65 (1.31 to 2.09) | <0.001 |
| 61-90 | 113 | 1.93 (1.32 to 2.84) | <0.001 | 1.75 (1.19 to 2.57) | <0.001 |
| ≥91 | 109 | 2.36 (1.73 to 3.25) | <0.001 | 1.9 (1.39 to 2.61) | <0.001 |
| Any DDDs | 1317 | 1.63 (1.45 to 1.82) | <0.001 | 1.57 (1.40 to 1.76) | <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.