| Category | Oil ever** (N=1908) | Oil Never** (N=1584) | |||||
| Acute respiratory conditions (ICD-9:460–466) | 304 | 3972 | 76.54 | 233 | 3275 | 71.14 | 1.07 (0.91 to 1.27) |
| Chronic respiratory conditions (ICD-9:471–474, 476- 478, 490–496, 506, 508) | 289 | 4007 | 72.12 | 184 | 3357 | 54.81 | 1.32 (1.09 to 1.58) |
| Asthma (ICD-9:493) | 41 | 4323 | 9.49 | 18 | 3553 | 5.07 | 1.83 (1.05 to 3.19) |
| COPD (ICD-9:490–496) | 92 | 4252 | 21.64 | 55 | 3500 | 15.71 | 1.36 (0.97 to 1.89) |
| Headaches and migraines (ICD-9:339, 346) | 79 | 4270 | 18.50 | 53 | 3509 | 15.10 | 1.35 (0.95 to 1.92) |
| Neurological conditions, excluding headaches/migraines (ICD-9:337, 341, 345, 348, 349) | 16 | 4340 | 3.69 | 9 | 3564 | 2.53 | 1.48 (0.66 to 3.36) |
| Dermal conditions (ICD-9:690–692, 694, 701, 702, 709) | 305 | 4002 | 76.21 | 211 | 3331 | 63.35 | 1.21 (1.01 to 1.44 |
*Responders’ follow-up period begins on the deployment end date. Non-responders’ follow-up period begins on the median of all responder
†Excludes medical encounters that occurred after a participant exited the USCG.
‡IR: incidence rate based on searching health encounter data dating back to October 2007 and excluding any cases identified prior to start of follow-up. Expressed as incidence per 1000 person years.
§In responder/non-responder analysis, rate ratio was adjusted for age for respiratory, asthma, COPD, neurological and dermal conditions. Rate ratio was adjusted for age and gender for headaches and migraines.
¶In oil ever/never analysis, rate ratio was adjusted for age and smoking for respiratory, asthma and COPD, age and gender for headaches and migraines, and age only for neurological and dermal conditions.
**Ever versus never exposed to oil as reported in surveys 1 and 2. Bold indicates statistically significant RR.
Bold typeface indicates statistical significance.
COPD, chronic obstructive pulmonary disease; ICD, International Classification of Diseases; P-Y, ‘person years’; RR, relative risks; USCG, US Coast Guard.