Table 2.
Adjusted general estimating equation and Cox regression models for depression and suicidal ideation
| All participants | Excluding those with the outcome at baseline | |||||||
|---|---|---|---|---|---|---|---|---|
| Depression | Suicidal ideation | Depression | Suicidal ideation | |||||
| EFV | NVP | EFV | NVP | EFV | NVP | EFV | NVP | |
| Proportion of participants ever with outcome* (%) | 61/305 (20.0%) | 125/389 (32.1%) | 19/305 (6.2%) | 47/389 (12.1%) | 17/206 (8.3%) | 52/260 (20.0%) | 14/284 (4.9%) | 35/363 (9.6%) |
| Proportion of person-visits with outcome (%) | 105/1522 (6.9%) | 228/2332 (9.8%) | 24/1522 (1.6%) | 62/2332 (2.7%) | 24/1014 (2.4%) | 86/1586 (5.4%) | 16/1405 (1.1%) | 41/2195 (1.9%) |
| Events/PY† | 49/430.0 | 142/598.4 | 15/478.4 | 52/699.6 | 15/313.3 | 57/444.2 | 11/451.5 | 39/662.4 |
| Crude IR (events/100 PY) | 11.4 | 23.7 | 3.1 | 7.4 | 4.8 | 12.8 | 2.4 | 5.9 |
| Crude IR difference‡ (95% CI) | −12.3 (−17.4, −7.3) | −4.2 (−6.8, −1.5) | −8.0 (−12.2, −3.9) | −3.5 (−5.8, −1.1) | ||||
| Crude IRR, (exact 95% CI) | 0.48 (0.34, 0.67), P<0.001 | 0.42 (0.22, 0.76), P=0.002 | 0.37 (0.20, 0.67), P<0.001 | 0.41 (0.19, 0.82), P=0.006 | ||||
| Adjusted risk of outcome at a visit§ (95% CI) | 6.6% (4.7, 8.5) | 9.7% (8.2, 11.2) | 1.6% (0.7, 2.5%) | 2.5% (1.8, 3.2%) | 2.1% (0.8, 3.5) | 5.0% (3.7, 6.4) | 1.0% (0.3, 1.7) | 1.9% (1.2, 2.5) |
| Adjusted risk difference at a visit§ (95% CI) | −3.1% (−5.8, −0.4), P=0.023 | −0.91% (−2.1, 0.3), P=0.143 | −2.9% (−5.0, −0.1), P=0.007 | −0.9% (−2.0, 0.2), P=0.097 | ||||
| GEE logistic regression aOR∥ (95% CI) | 0.62 (0.40, 0.96), P=0.032 | 0.61 (0.30, 1.25), P=0.178 | 0.40 (0.18,0.87), P=0.020 | 0.50 (0.20,1.25), P=0.138 | ||||
| Cox regression aHR¶ (95% CI) | 0.56 (0.35, 0.89), P=0.013 | 0.47 (0.21, 1.07), P=0.072 | 0.38 (0.17, 0.83), P=0.015 | 0.47 (0.18, 1.22), P=0.121 | ||||
| Weighted marginal structural model aOR** (95% CI) | 0.42 (0.21, 0.81), P=0.010 | 0.54 (0.25, 1.19), P=0.126 | 0.43 (0.16, 1.21), P=0.112 | 0.37 (0.15, 0.89), P=0.026 | ||||
ART = antiretroviral therapy; EFV = efavirenz; NVP = nevirapine; PY = person-year; IR = incidence rate; CI = confidence interval; IRR = incidence rate ratio; GEE = generalized estimating equations; aOR = adjusted odds ratio; aHR = adjusted hazard ratio
Comparing participants in ever-EFV vs only-NVP groups
Attributed events and person-time accounting for time-varying exposure; corresponding measures that follow also account for time-varying exposure
All measures of effect and association comparing efavirenz use to nevirapine use
Adjusted risk and risk differences based on GEE model estimates
In GEE model, efavirenz use was treated as a time-varying exposure and adjusted for the following time-dependent covariates: age, sex, marital status, educational attainment, household asset ownership, CD4+ T-lymphocyte count, viral suppression, ART duration, health status, and heavy drinking; and the following time-independent covariates: year of enrollment, probable depression at enrollment, suicidal ideation at enrollment, and tuberculosis co-infection.
In Cox model, efavirenz use treated as a time-varying exposure and adjusted for the following baseline, time-independent covariates: age, sex, marital status, educational attainment, household asset ownership, CD4+ T-lymphocyte count, viral suppression, RT duration, health status, heavy drinking, year of enrollment, probable depression, suicidal ideation, and tuberculosis co-infection
See methods appendix for details on model specification