Guideline-adherent treatment regimen during baseline, interview and intervention periods
| Characteristic | Intervention clinic | Control clinic | Difference-in-differences estimator (p value) | ||||
| Baseline | Interviews | Intervention | Baseline | Interviews | Intervention | ||
| Guideline-adherent regimens*, (n) | 71 | 79 | 93 | 8 | 15 | 15 | NA |
| Total prescriptions, (n) | 214 | 193 | 139 | 152 | 146 | 88 | NA |
| Proportion† of guideline-adherent regimens and 95% CI | 33.2 (26.9 to 39.9) | 40.9 (33.9 to 48.2) | 66.9 (58.4 to 74.6) | 5.3 (2.3 to 10.1) | 10.3 (5.9 to 16.4) | 17.0 (9.9 to 26.6) | 22 (0.01)‡ |
Baseline period was from July 2016 to March 2017, interviews from April 2017 to March 2018 and intervention from April 2018 to February 2019.
*Including nitrofurantoin for 5 days or trimethoprim–sulfamethoxazole for 3 days.
†Proportion of guideline-adherent regimens was calculated by dividing guideline-adherent regimens by the total number of antibiotic prescriptions.
‡The difference-in-differences estimator is calculated by subtracting the change in proportion of guideline-adherent regimens between the intervention and baseline periods of the control site (17.0%–5.3%) from the change in proportion of guideline-adherent regimens between the intervention and baseline periods of the intervention site (66.9%–33.2%=33.7%), which is equal to 33.7%–11.7%=22%. The p value refers to the interaction term between study clinic (intervention and control) and study period (baseline, interviews and intervention) in the log-binomial regression analysis, implying that the increase in guideline adherence was significantly greater in the intervention site compared with the control site.