Table 3.
Multivariable analysis of factors associated with productive days lost.
| Zambia | South Africa | |||
| Model 1a | Model 1b | Model 2a | Model 2b | |
| HIV-negative (base) | -- | -- | -- | -- |
| HIV-positive | 0.74***[0.48–1.01] | 0.13***[0.04–0.23] | ||
| P < 0.001 | P = 0.007 | |||
| HIV-positive not on ART | 0.61***[0.30–0.92] | 0.03[−0.05 to 0.11] | ||
| P < 0.001 | P = 0.416 | |||
| HIV-positive on ART < 1 year | 1.24***[0.34–2.14] | 1.41 [−0.004 to 2.82] | ||
| P = 0.007 | P = 0.051 | |||
| HIV-positive on ART 1–2years | 1.08**[0.06–2.11] | 0.18 [−0.19 to 0.54] | ||
| P = 0.038 | P = 0.341 | |||
| HIV-positive on ART 3 or more years | 0.79**[0.16–1.41] | 0 [−0.13 to 0.14] | ||
| P = 0.014 | P = 0.961 | |||
| In the labour force (base) | -- | -- | -- | -- |
| Not in the labour force | −0.05 [−0.21 to 0.11] | −0.04 [−0.20 to 0.12] | 0 [−0.08 to 0.08] | 0.001 [−0.07 to 0.07] |
| P = 0.571 | P = 0.592 | P = 0.989 | P = 0.982 | |
| Under 25 years (base) | -- | -- | -- | -- |
| 25–34 years | 0.25*** [0.08–0.41] | 0.24*** [0.08–0.40] | 0.06** [0.01–0.12] | 0.05 [−0.01 to 0.10] |
| P = 0.003 | P = 0.004 | P = 0.031 | P = 0.082 | |
| 35–44 years | 0.73***[0.44–1.02] | 0.72***[0.43–1.02] | 0.11*** [0.03–0.19] | 0.11***[0.03–0.19] |
| P < 0.001 | P < 0.001 | P = 0.006 | P = 0.006 | |
| Female (base) | -- | -- | -- | -- |
| Male | −0.05 [−0.22 to 0.12] | −0.04 [−0.21 to 0.13] | −0.08***[−0.14 to −0.03] | −0.10*** [−0.15 to −0.05] |
| P = 0.593 | P = 0.626 | P = 0.002 | P = < 0.000 | |
| Bemba (base Zambia)/Xhosa (base South Africa) | -- | -- | -- | -- |
| Tonga (Zambia)/Multiracial (South Africa) | 0.13 [−0.16 to 0.41] | 0.14 [−0.15 to 0.42] | 0.01 [−0.09 to 0.11] | 0.01 [−0.08 to 0.10] |
| P = 0.383 | P = 0.353 | P = 0.841 | P = 0.850 | |
| Lozi (Zambia)/Afrikaans (South Africa) | 0.15 [−0.20 to 0.49] | 0.14 [−0.20 to 0.48] | 0.87 [−0.84 to 2.59] | 0.81 [−0.77 to 2.40] |
| P = 0.403 | P = 0.418 | P = 0.319 | P = 0.314 | |
| Chewa (Zambia) | 0.22 [−0.12 to 0.57] | 0.23 | ||
| P = 0.209 | [−0.12 to 0.57] P = 0.201 | |||
| Other | 0.03 [−0.14 to 0.20] | 0.03 [−0.14 to 0.21] | −0.06 [−0.14 to 0.02] | −0.07** [−0.14 to −0.00] |
| P = 0.728 | P = 0.711 | P = 0.164 | P = 0.045 | |
| School education less than grade 8 (primary school, base) | ||||
| School education between grades 8 and 12 (secondary school) | −0.23** [−0.43 to −0.03] | −0.23** [−0.43 to −0.03] | −0.13 [−0.29 to 0.03] | −0.04 [−0.16 to 0.08] |
| P = 0.026 | P = 0.025 | P = 0.228 | P = 0.513 | |
| College, university, or other higher education | −0.2 [−0.54 to 0.14] | −0.19 [−0.53 to 0.15] | −0.14 [−0.33 to 0.04] | −0.05 [−0.20 to 0.10] |
| P = 0.260 | P = 0.265 | P = 0.135 | P = 0.505 | |
| Does not use recreational drugs | ||||
| Uses recreational drugs | 0.54 [−0.16 to 1.24] | 0.53 [−0.17 to 1.22] | 0.14 [−0.09 to 0.36] | 0.16 [−0.07 to 0.40] |
| P = 0.131 | P = 0.137 | P = 0.235 | P = 0.169 | |
| Community fixed effects | Yes | Yes | Yes | Yes |
| N | 17 397 | 17 324 | 16 219 | 16 086 |
| Likelihood ratio test (Ho: α = 0) | ||||
| χ2 | 86 000 | 85 000 | 26 000 | 26 000 |
| Prob at least χ2 | 0.0000 | 0.0000 | 0.0000 | 0.0000 |
Symbols (***) and (**) denote 99% and 95% statistical confidence levels, respectively; presented are marginal effects evaluated at the means of all other covariates; data are change in mean PDLs (95% CI), unless otherwise stated. For all factor variables, each category is compared with the base category. ART, antiretroviral therapy; CI, confidence interval.