Table 5.
Mediation analysis for the association between socio‐economic position and prevalent TB
| Putative mediator | Zambiaa | South Africab | |||||
|---|---|---|---|---|---|---|---|
| Direct Effect Odds Ratio (95% CI) | Indirect Effect Odds Ratio (95% CI) | Total Effect Odds Ratio (95% CI) | Direct Effect Odds Ratio (95% CI) | Indirect Effect Odds Ratio (95% CI) | Total Effect Odds Ratio (95% CI) | ||
| Educational attainment | |||||||
| Smoking | None | 1.40 (074–2.67) | 1.01 (0.96–1.06) | 1.41 (0.74–2.70) | 1.11 (0.78–1.58) | 0.99 (0.87–1.13) | 1.10 (0.75–1.61) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.76 (0.52–1.10) | 0.96 (0.92–0.99) | 0.72 (0.50–1.06) | 0.81 (0.64–1.02) | 1.00 (0.92–1.07) | 0.80 (0.63–1.03) | |
| Upper secondary | 0.70 (0.47–1.03) | 0.92 (0.87–0.98) | 0.64 (0.44–0.95) | 0.67 (0.54–0.83) | 0.96 (0.89–1.03) | 0.64 (0.51–0.81) | |
| College or university | 0.29 (0.13–0.63) | 0.92 (0.86–0.98) | 0.26 (0.12–0.58) | 0.44 (0.26–0.75) | 0.89 (0.76–1.04) | 0.39 (0.23–0.68) | |
| Alcohol | None | 1.45 (0.76–2.77) | 0.97 (0.92–1.02) | 1.41 (0.74–2.69) | 1.12 (0.78–1.59) | 0.99 (0.90–1.08) | 1.10 (0.76–1.59) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.74 (0.51–1.07) | 1.00 (0.98–1.03) | 0.74 (0.51–1.07) | 0.81 (0.64–1.02) | 0.99 (0.94–1.05) | 0.80 (0.63–1.02) | |
| Upper secondary | 0.67 (0.45–0.98) | 0.99 (0.96–1.02) | 0.66 (0.45–0.97) | 0.65 (0.52–0.81) | 0.98 (0.93–1.03) | 0.64 (0.51–0.80) | |
| College or university | 0.27 (0.12–0.59) | 1.01 (0.98–1.05) | 0.27 (0.12–0.59) | 0.42 (0.24–0.71) | 0.97 (0.89–1.06) | 0.40 (0.23–0.69) | |
| Malnutrition | None | 1.37 (0.72–2.60) | 1.00 (0.97–1.03) | 1.37 (0.72–2.61) | 1.10 (0.77–1.56) | 1.00 (1.00–1.00) | 1.10 (0.77–1.56) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.74 (0.50–1.07) | 1.00 (0.98–1.02) | 0.73 (0.50–1.07) | 0.80 (0.63–1.02) | 1.00 (1.00–1.00) | 0.80 (0.63–1.02) | |
| Upper secondary | 0.66 (0.45–0.97) | 1.00 (0.96–1.03) | 0.66 (0.44–0.97) | 0.64 (0.52–0.80) | 1.00 (1.00–1.00) | 0.64 (0.52–0.80) | |
| College or university | 0.26 (0.12–0.58) | 1.00 (0.95–1.05) | 0.26 (0.12–0.57) | 0.41 (0.24–0.69) | 1.00 (1.00–1.00) | 0.41 (0.24–0.69) | |
| Diabetes | None | 1.37 (0.72–2.61) | 1.00 (1.00–1.00) | 1.37 (0.72–2.61) | 1.09 (0.77–1.56) | 1.00 (1.00–1.00) | 1.09 (0.77–1.56) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.73 (0.50–1.07) | 1.00 (1.00–1.00) | 0.73 (0.50–1.07) | 0.80 (0.64–1.02) | 1.00 (1.00–1.00) | 0.80 (0.64–1.02) | |
| Upper secondary | 0.66 (0.44–0.97) | 1.00 (1.00–1.00) | 0.66 (0.44–0.97) | 0.64 (0.52–0.80) | 1.00 (1.00–1.00) | 0.64 (0.52–0.80) | |
| College or university | 0.26 (0.12–0.57) | 1.00 (1.00–1.00) | 0.26 (0.12–0.57) | 0.40 (0.24–0.69) | 1.00 (1.00–1.00) | 0.40 (0.24–0.69) | |
| Indoor air pollution | None | 1.37 (0.72–2.60) | 1.00 (0.89–1.12) | 1.37 (0.71–2.63) | Very few South Africans exposed to indoor air pollution | ||
| Primary | Referent | ||||||
| Lower secondary | 0.75 (0.52–1.10) | 0.98 (0.93–1.05) | 0.74 (0.51–1.08) | ||||
| Upper secondary | 0.69 (0.46–1.01) | 0.97 (0.90–1.04) | 0.66 (0.45–0.98) | ||||
| College or university | 0.29 (0.13–0.63) | 0.92 (0.82–1.05) | 0.26 (0.12–0.58) | ||||
| Household crowding | None | 1.36 (0.72–2.59) | 1.00 (0.96–1.05) | 1.37 (0.72–.2.60) | 1.09 (0.77–1.56) | 1.00 (0.93–1.08) | 1.09 (0.76–1.57) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.73 (0.50–1.06) | 1.00 (0.98–1.03) | 0.73 (0.50–1.07) | 0.80 (0.63–1.01) | 1.00 (0.96–1.04) | 0.80 (0.63–1.02) | |
| Upper secondary | 0.65 (0.44–0.96) | 1.01 (0.98–1.04) | 0.66 (0.44–0.97) | 0.64 (0.52–0.80) | 1.00 (0.96–1.04) | 0.64 (0.51–0.80) | |
| College or university | 0.26 (0.12–0.56) | 1.02 (0.96–1.08) | 0.26 (0.12–0.57) | 0.40 (0.24–0.68) | 1.00 (0.93–1.09) | 0.40 (0.24–0.69) | |
| Migration | None | 1.39 (0.73–2.65) | 0.98 (0.83–1.16) | 1.37 (0.70–2.66) | 1.10 (0.77–1.57) | 1.00 (0.65–1.54) | 1.10 (0.63–1.93) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.74 (0.51–1.08) | 0.99 (0.92–1.07) | 0.74 (0.50–1.08) | 0.80 (0.63–1.01) | 1.00 (0.83–1.20) | 0.80 (0.59–1.08) | |
| Upper secondary | 0.67 (0.46–1.00) | 0.98 (0.90–1.06) | 0.66 (0.44–0.98) | 0.64 (0.51–0.79) | 1.00 (0.85–1.18) | 0.64 (0.48–0.84) | |
| College or university | 0.27 (0.12–0.60) | 0.96 (0.84–1.09) | 0.26 (0.12–0.58) | 0.40 (0.23–0.68) | 1.00 (0.79–1.26) | 0.40 (0.22–0.71) | |
| HIV (complete casec) | None | 1.77 (0.92–3.41) | 0.99 (0.98–1.00) | 1.75 (0.91–3.37) | 1.47 (0.93–2.33) | 0.99 (0.98–1.00) | 1.46 (0.92–2.31) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.86 (0.58–1.29) | 1.00 (1.00–1.00) | 0.87 (0.58–1.29) | 1.17 (0.86–1.59) | 0.99 (0.98–1.00) | 1.16 (0.85–1.57) | |
| Upper secondary | 0.81 (0.53–1.23) | 0.98 (0.98–0.99) | 0.80 (0.52–1.22) | 1.01 (0.76–1.35) | 0.98 (0.96–0.99) | 0.99 (0.74–1.32) | |
| College or university | 0.30 (0.12–0.75) | 0.97 (0.96–0.99) | 0.29 (0.12–0.73) | 0.83 (0.46–1.51) | 0.95 (0.92–0.98) | 0.79 (0.44–1.43) | |
| HIV (MAR d) | None | 1.45 (0.78–2.71) | 0.98 (0.97–1.00) | 1.43 (0.77–2.66) | 1.03 (0.71–1.48) | 1.00 (0.97–1.02) | 1.02 (0.71–1.47) |
| Primary | Referent | Referent | |||||
| Lower secondary | 0.77 (0.54–1.12) | 1.00 (1.00–1.01) | 0.78 (0.54–1.12) | 0.83 (0.65–1.05) | 0.99 (0.97–1.00) | 0.82 (0.65–1.03) | |
| Upper secondary | 0.73 (0.49–1.07) | 0.98 (0.97–0.99) | 0.71 (0.49–1.05) | 0.67 (0.54–0.83) | 0.98 (0.97–0.99) | 0.66 (0.53–0.81) | |
| College or university | 0.30 (0.14–0.66) | 0.97 (0.96–0.99) | 0.29 (0.13–0.64) | 0.46 (0.27–0.78) | 0.95 (0.92–0.98) | 0.44 (0.26–0.74) | |
| Household wealth | |||||||
| Smoking | Very low | Referent | Referent | ||||
| Low | 0.81 (0.55–1.19) | 0.96 (0.93–0.99) | 0.78 (0.53–1.14) | 0.79 (0.63–0.99) | 1.00 (0.93–1.07) | 0.78 (0.62–1.00) | |
| Medium | 0.58 (0.37–0.89) | 0.93 (0.88–0.98) | 0.54 (0.35–0.83) | 0.76 (0.60–0.96) | 0.98 (0.91–1.06) | 0.75 (0.58–0.96) | |
| High | 0.60 (0.37–0.96) | 0.92 (0.86–0.98) | 0.55 (0.34–0.88) | 0.69 (0.53–0.88) | 0.97 (0.90–1.05) | 0.66 (0.51–0.87) | |
| Alcohol | Very low | Referent | Referent | ||||
| Low | 0.80 (0.55–1.17) | 0.99 (0.97–1.02) | 0.79 (0.54–1.16) | 0.77 (0.61–0.97) | 1.02 (0.97–1.07) | 0.79 (0.62–0.99) | |
| Medium | 0.55 (0.36–0.85) | 1.00 (0.97–1.02) | 0.55 (0.36–0.85) | 0.74 (0.59–0.94) | 1.01 (0.96–1.06) | 0.75 (0.59–0.96) | |
| High | 0.56 (0.35–0.89) | 1.01 (0.98–1.04) | 0.56 (0.35–0.90) | 0.68 (0.53–0.87) | 0.98 (0.93–1.04) | 0.67 (0.52–0.86) | |
| Malnutrition | Very low | Referent | Referent | ||||
| Low | 0.79 (0.54–1.16) | 1.00 (0.98–1.02) | 0.79 (0.54–1.16) | 0.79 (0.63–0.99) | 1.00 (1.00–1.00) | 0.79 (0.63–0.99) | |
| Medium | 0.55 (0.35–0.85) | 1.00 (0.96–1.04) | 0.55 (0.35–0.84) | 0.75 (0.59–0.95) | 1.00 (1.00–1.00) | 0.75 (0.59–0.95) | |
| High | 0.56 (0.35–0.90) | 1.00 (0.94–1.05) | 0.56 (0.35–0.89) | 0.67 (0.52–0.86) | 1.00 (1.00–1.00) | 0.67 (0.52–0.86) | |
| Diabetes | Very low | Referent | Referent | ||||
| Low | 0.79 (0.54–1.15) | 1.00 (1.00–1.00) | 0.79 (0.54–1.15) | 0.79 (0.63–0.99) | 1.00 (1.00–1.00) | 0.79 (0.63–0.99) | |
| Medium | 0.54 (0.35–0.84) | 1.00 (1.00–1.01) | 0.54 (0.35–0.84) | 0.75 (0.59–0.95) | 1.00 (1.00–1.00) | 0.75 (0.59–0.95) | |
| High | 0.55 (0.34–0.89) | 1.00 (1.00–1.01) | 0.55 (0.34–0.89) | 0.67 (0.52–0.86) | 1.00 (1.00–1.00) | 0.67 (0.52–0.86) | |
| Indoor air pollution | Very low | Referent | Very few South Africans exposed to indoor air pollution | ||||
| Low | 0.80 (0.55–1.18) | 0.99 (0.92–1.06) | 0.80 (0.54–1.17) | ||||
| Medium | 0.59 (0.38–0.91) | 0.94 (0.86–1.04) | 0.55 (0.36–0.86) | ||||
| High | 0.63 (0.38–1.03) | 0.89 (0.76–1.04) | 0.56 (0.35–0.91) | ||||
| Household crowding | Very low | Referent | Referent | ||||
| Low | 0.79 (0.54–1.15) | 1.00 (0.98–1.02) | 0.79 (0.54–1.16) | 0.78 (0.62–0.99) | 1.00 (0.95–1.05) | 0.79 (0.62–0.99) | |
| Medium | 0.54 (0.35–0.84) | 1.00 (0.98–1.03) | 0.55 (0.35–0.84) | 0.75 (0.59–0.95) | 1.00 (0.95–1.05) | 0.75 (0.59–0.96) | |
| High | 0.55 (0.34–0.88) | 1.01 (0.97–1.05) | 0.55 (0.35–0.89) | 0.66 (0.51–0.86) | 1.00 (0.94–1.07) | 0.67 (0.51–0.86) | |
| Migration | Very low | Referent | Referent | ||||
| Low | 0.80 (0.55–1.17) | 0.99 (0.91–1.07) | 0.79 (0.53–1.16) | 0.77 (0.61–0.97) | 1.00 (0.86–1.16) | 0.77 (0.59–1.02) | |
| Medium | 0.56 (0.36–0.86) | 0.98 (0.90–1.06) | 0.54 (0.35–0.85) | 0.74 (0.58–0.93) | 1.00 (0.85–1.17) | 0.74 (0.55–0.98) | |
| High | 0.58 (0.36–0.93) | 0.96 (0.88–1.06) | 0.56 (0.34–0.90) | 0.65 (0.50–0.84) | 1.00 (0.85–1.17) | 0.65 (0.48–0.88) | |
| HIV (complete casec) | Very low | Referent | Referent | ||||
| Low | 0.80 (0.53–1.21) | 1.00 (1.00–1.00) | 0.80 (0.53–1.12) | 0.72 (0.53–0.96) | 0.98 (0.97–0.99) | 0.70 (0.52–0.95) | |
| Medium | 0.62 (0.39–0.99) | 0.99 (0.99–1.00) | 0.61 (0.39–0.98) | 0.82 (0.61–1.10) | 0.99 (0.98–1.00) | 0.81 (0.60–1.09) | |
| High | 0.68 (0.40–1.15) | 0.98 (0.96–0.99) | 0.67 (0.39–1.12) | 0.66 (0.48–0.92) | 0.98 (0.96–0.99) | 0.65 (0.47–0.90) | |
| HIV (MARd) | Very low | Referent | Referent | ||||
| Low | 0.78 (0.54–1.13) | 1.00 (1.00–1.01) | 0.78 (0.54–1.14) | 0.86 (0.69–1.08) | 0.97 (0.96–0.99) | 0.84 (0.67–1.06) | |
| Medium | 0.57 (0.37–0.87) | 0.99 (0.98–1.00) | 0.57 (0.37–0.87) | 0.83 (0.65–1.05) | 0.98 (0.96–0.99) | 0.81 (0.64–1.03) | |
| High | 0.64 (0.40–1.02) | 0.97 (0.96–0.99) | 0.62 (0.39–0.99) | 0.74 (0.57–0.96) | 0.97 (0.94–0.99) | 0.72 (0.56–0.93) | |
a
2410 Zambians with missing data on age, household crowding or migration excluded from these mediation analyses.
b
961 South Africans with missing data on age, household crowding or migration excluded from these mediation analyses.
c
The measure incorporating self‐report (see Table 1).
d
Missing HIV status imputed under the Missing at Random assumption.