Table 3.
Associations between potential risk factors and catastrophic costs among patients with tuberculosis in Limpopo Province, South Africa* (n = 297)†
| Potential risk factors | Prevalence of catastrophic costs n (%) | Univariable PR (95%CI) | aPR (95%CI) |
|---|---|---|---|
| Sex | |||
| Male | 47 (27) | Reference | Reference |
| Female | 39 (32) | 1.2 (0.8–1.7) | 1.2 (0.7–2.0) |
| Age, years‡ | |||
| 18–24 | 8 (25) | Reference | Reference |
| 25–34 | 13(18) | 0.7 (0.3–1.6) | 0.6 (0.2–1.6) |
| 35–44 | 31 (34) | 1.3 (0.7–2.6) | 1.1 (0.4–2.8) |
| 45–59 | 26 (35) | 1.4 (0.7–2.7) | 1.1 (0.4–2.9) |
| ≥60 | 8 (31) | 1.2 (0.5–2.8) | 1.6 (0.5–5.2) |
| Number of household members | |||
| 1–2 | 23 (38) | Reference | Reference |
| 3–4 | 27 (29) | 0.8 (0.5–1.2) | 0.8 (0.5–1.3) |
| 5–6 | 17(22) | 0.6§ (0.3–1.0) | 0.6§ (0.3–1.0) |
| ≥7 | 19 (28) | 0.8 (0.5–1.2) | 0.8 (0.5–1.3) |
| Duration of primary symptom, months | |||
| <2 | 51 (28) | Reference | Reference |
| 2–4 | 20 (27) | 1.0 (0.6–1.5) | 1.0 (0.6–1.5) |
| >4 | 15 (38) | 1.4 (0.9–2.2) | 1.1(0.7–1.9) |
| Tobacco smoking, pack-years | |||
| Never smoked | 49 (29) | Reference | Reference |
| <5 | 19 (27) | 0.9 (0.6–1.5) | 0.9 (0.5–1.7) |
| 5–< 15 | 9 (24) | 0.8 (0.5–1.6) | 0.8 (0.4–1.6) |
| ≥15 | 9 (50) | 1.7¶(1.0–2.9) | 1.6 (0.8–3.4) |
| HIV status | |||
| Not infected | 34 (26) | Reference | Reference |
| Living with HIV | 52 (32) | 1.2 (0.9–1.8) | 1.0 (0.7–1.6) |
| Distance to clinic, min | |||
| <15 | 14 (25) | Reference | Reference |
| 15–59 | 45 (25) | 1.0 (0.6–1.7) | 1.0 (0.6–1.6) |
| 60–89 | 17 (45) | 1.8§ (1.0–3.1) | 1.7§ (0.9–3.1) |
| ≥90 | 10 (38) | 1.5 (0.8–2.9) | 1.6 (0.8–3.2) |
| Employment category | |||
| Temporary/informal | 9 (22) | Reference | Reference |
| Unemployed, cannot work | 33 (38) | 1.7§ (0.9–3.2) | 2.0§ (1.0–4.0) |
| Unemployed, could work | 20 (28) | 1.3 (0.6–2.5) | 1.8 (0.8–4.1) |
| Retired | 6 (24) | 1.1 (0.4–2.7) | 1.1 (0.3–3.7) |
| Student | 4 (24) | 1.1 (0.4–3.0) | 1.4 (0.4–5.3) |
| Self-employed | 4 (31) | 1.4 (0.5–3.8) | 1.7 (0.6–5.2) |
| Salaried | 10 (24) | 1.1 (0.5–2.4) | 1.4 (0.6–3.3) |
| Highest grade attended by any household member | |||
| ≤4th | 13 (30) | Reference | Reference |
| 5–9th | 25 (29) | 1.3 (0.8–2.2) | 1.1 (0.6–1.9) |
| 10–12th | 42 (28) | 1.1 (0.7–1.8) | 1.2 (0.7–2.0) |
| Any postgraduate | 6 (32) | 1.1 (0.5–2.6) | 1.4 (0.6–3.4) |
| SAMPI,# SEP | |||
| Lowest SEP | 31 (31) | Reference | Reference |
| Middle SEP | 40 (32) | 1 (0.7–1.5) | 1.1 (0.7–1.7) |
| Highest SEP | 15 (21) | 0.7 (0.4–1.2) | 0.7 (0.4–1.4) |
Catastrophic costs assessed using the ‘minimum cost threshold’ method as described in the text.
Thirty observations with missing values of risk factor covariates were excluded from all univariable analyses to obtain the sample size of 297. The missing values are included in separate missing categories in Table 1 under four risk factors: symptom duration, tobacco smoking, employment, and clinic travel time.
Using the 25–34 years age group as reference, we observed a greater prevalence of catastrophic costs among those aged ≥60 years (aPR 2.6, 95%CI 1.0–6.8).
0.10 < P < 0.05.
0.05 ≤ P < 0.01.
For 26 (8%) participants, the indicator for years of school attended by adults was assumed to be <5 years if the index case and head of household had attended <5 years, regardless of the number of household members.
PR = prevalence ratio; aPR = adjusted PR; HIV = human immunodeficiency virus; SAMPI = South Africa Multidimensional Poverty Index; SEP = socioeconomic placement.