Table 3.
Multivariable linear regression models of predictors of plasma ln(DDT) levels [% change in DDT levels (95% CI)] among South African women 20–30 years of age, 2010–2011 by exposure group.a
| Predictor | Unpsrayed (n = 175) | non-DDT IRS (n = 106) | DDT IRS (n = 100) | |||
|---|---|---|---|---|---|---|
| Percent change (95% CI)a | Adj. R2 | Percent change (95% CI)a | Adj. R2 | Percent change (95% CI)a | Adj. R2 | |
| Age (years) | ||||||
| 20–22 | NS | Referent | NS | |||
| 23–25 | NS | 69 (–4, 197) | NS | |||
| 26–28 | NS | 270 (79, 665) | NS | |||
| 29–30 | NS | 129 (4, 405) | 0.03 | NS | ||
| Education (years) | ||||||
| ≤ 11 | NS | Referent | NS | |||
| 12 | NS | 50 (–5, 137) | NS | |||
| > 12 | NS | –53 (–77, –7) | 0.03 | NS | ||
| Parity | ||||||
| Nulliparous | NS | Referent | NS | |||
| 1 | NS | –65 (–80, –37) | NS | |||
| > 1 | NS | –63 (–83, –17) | 0.04 | NS | ||
| Livestock ownership | ||||||
| No | NS | NS | Referent | |||
| Yes | NS | NS | 95 (26, 201) | 0.06 | ||
| Water source | ||||||
| Public tap | Referent | NS | NS | |||
| Piped to yard/home | –73 (–83, –57) | 0.16 | NS | NS | ||
| Butter consumption | ||||||
| < 1 time/month | Referent | Referent | NS | |||
| ≥ 1 time/month and < 1 time/day | 100 (19, 238) | –28 (–57, 22) | NS | |||
| ≥ 1 time/day | 105 (20, 251) | 0.02 | 36 (–21, 134) | 0.05 | NS | |
| Milk consumption | ||||||
| < 1 time/month | NS | Referent | NS | |||
| 1–4 times/month | NS | –36 (–61, 5) | 0.02 | NS | ||
| > 4 times/month | NS | –39 (–64, 6) | NS | |||
| Egg consumption | ||||||
| < 1 time/month | Referent | NS | NS | |||
| 1–6 times/month | –29 (–56, 16) | NS | NS | |||
| > 6 times/month | –54 (–73, –22) | 0.03 | NS | NS | ||
| Chicken consumption | ||||||
| ≤ 1 time/week | NS | Referent | NS | |||
| 2 times/week | NS | –23 (–57, 39) | NS | |||
| 3 times/week | NS | –50 (–70, –14) | NS | |||
| > 3 times/week | NS | –53 (–73, –17) | 0.04 | NS | ||
| Fish consumption | ||||||
| < 1 time/month | NS | Referent | NS | |||
| 1–4 times/month | NS | –54 (–72, –24) | NS | |||
| > 4 times/month | NS | 14 (–35, 100) | 0.03 | NS | ||
| Any pesticide touched open foods | ||||||
| No | NA | NS | Referent | |||
| Yes | NA | NS | 78 (–1, 221) | |||
| Any pesticide touched covering on foods | ||||||
| No | NA | Referent | NS | |||
| Yes | NA | 84 (13, 200) | 0.03 | NS | ||
| No. of actions taken before IRS | ||||||
| < 4 | NA | Referent | Referent | |||
| 4–6 | NA | 112 (31, 241) | 7 (–37, 82) | |||
| > 6 | NA | –20 (–52, 31) | 0.02 | –40 (–63, –0.3) | 0.04 | |
| Abbreviations: NA, not applicable; NS, not selected. All models are adjusted for total lipids. aCalculated using the following formula: [exp(β) – 1] × 100. | ||||||