Table 2. Outcomesa.
| Variable | Benzodiazepine-naive patients | Patients with preoperative benzodiazepine use | |||||
|---|---|---|---|---|---|---|---|
| Long-term | Intermittent | ||||||
| Measure (95% CI) | Difference or OR (95% CI) | P value | Measure (95% CI) | Difference or OR (95% CI) | P value | ||
| Primary outcomes (postoperative days 91-365) | |||||||
| Probability of any opioid prescribed, % (95% CI) | |||||||
| Unadjusted | 13.6 (13.5 to 13.6) | 22.4 (21.9 to 23.0) | OR, 1.84 (1.79 to 1.90) | <.001 | 21.1 (20.8 to 21.5) | OR, 1.71 (1.67 to 1.75) | <.001 |
| Adjustedb | 13.0 (12.9 to 13.1) | 19.2 (18.7 to 19.7) | OR, 1.59 (1.54 to 1.65) | <.001 | 18.0 (17.7 to 18.4) | OR, 1.47 (1.44 to 1.51) | <.001 |
| Average daily opioid prescribed among patients still using opioids, MME (95% CI)c | |||||||
| Unadjusted | 2.7 (2.6 to 2.7) | 3.9 (3.6 to 4.2) | Difference, 1.2 (0.9 to 1.5) | <.001 | 2.9 (2.7 to 3.0) | Difference, 0.2 (0.0 to 0.4) | .03 |
| Adjustedb | 2.7 (2.7 to 2.8) | 3.3 (3.0 to 3.6) | Difference, 0.6 (0.3 to 0.8) | <.001 | 2.7 (2.5 to 2.9) | Difference, 0.0 (−0.2 to 0.2) | .65 |
| Secondary outcomes | |||||||
| Average daily opioid prescribed in postoperative days 0-90, MME (95% CI)c | |||||||
| Unadjusted | 5.9 (5.9 to 5.9) | 7.8 (7.5 to 8.0) | Difference, 1.9 (1.6 to 2.1) | <.001 | 6.4 (6.2 to 6.5) | Difference, 0.5 (0.4 to 0.6) | <.001 |
| Adjustedb | 5.9 (5.9 to 5.9) | 6.7 (6.5 to 6.9) | Difference, 0.8 (0.6 to 0.9) | <.001 | 6.3 (6.2 to 6.4) | Difference, 0.3 (0.2 to 0.4) | <.001 |
| Total health care costs in postoperative days 0-30, $ (95% CI) | |||||||
| Unadjusted | 22 035 (21 977 to 22 093) | 22 267 (21 909 to 22 626) | Difference, 232 (−130 to 595) | .20 | 25 158 (24 876 to 25 440) | Difference, 3123 (2835 to 3411) | <.001 |
| Adjustedb | 22 138 (22 089 to 22 186) | 22 238 (21 938 to 22 538) | Difference, 101 (−204 to 405) | .52 | 23 293 (23 082 to 23 504) | Difference, 1155 (938 to 1372) | <.001 |
Abbreviation: MME, morphine milligram equivalents.
a
Both long-term and intermittent benzodiazepine use were associated with an increased likelihood to continue to use opioids after surgery and higher opioid dose requirements in the immediate postoperative period. Long-term benzodiazepine use was also associated with increased opioid doses beyond the immediate postoperative period. Intermittent benzodiazepine use was associated with increased 30-day health care costs.
b
Results were adjusted for age, sex, type and year of surgery, and medical comorbidities using regression modeling.
c
Patients who were not prescribed any opioid in the referenced time period were excluded from the analysis to prevent downward biasing of the results.