Table 4.
Marginal Hazard Ratios of the Association of Median Total Hydrocarbon Exposure Before the Oil Well Was Capped and Self-Reported Myocardial Infarction/Fatal Coronary Heart Disease, Gulf Long-Term Follow-up Study, United States, 2010–2016
| Median THC Exposure, ppm | Total Cases (n = 289) | Total No.a (n = 22,200) | HRb | 95% CI |
|---|---|---|---|---|
| No censoring weights | ||||
| <0.10 | 40 | 4,386 | 1.00 | Referent |
| 0.10–0.29 | 106 | 7,715 | 1.44 | 1.01, 2.06 |
| 0.30–0.99 | 126 | 8,940 | 1.27 | 0.89, 1.80 |
| ≥1.00 | 17 | 1,159 | 1.35 | 0.75, 2.43 |
| IP-censoring weightedc | ||||
| <0.10 | 40 | 4,363 | 1.00 | Referent |
| 0.10–0.29 | 106 | 7,682 | 1.58 | 1.04, 2.40 |
| 0.30–0.99 | 126 | 8,904 | 1.32 | 0.88, 2.00 |
| ≥1.00 | 17 | 1,154 | 1.47 | 0.78, 2.78 |
Abbreviations: CI, confidence interval; HR, hazard ratio; IP, inverse probability; ppm, parts per million; THC, total hydrocarbons.
a Total n for models without censoring weights is where median THC exposure, sex, age, smoking, education, and residential proximity to the spill are nonmissing; total n for models with censoring weights is where ethnicity is also nonmissing.
b Models controlled for sex, age, smoking, education, and residential proximity to the oil spill using inverse probability of exposure weights.
c Censoring weights accounted for age, ethnicity, education, residential proximity to the oil spill, smoking, and maximum total hydrocarbon exposure.