Table 2.
Multiple Deployments, Deployment Duration, and Adjusted Relative Risk of New-Onset Asthma According to Sex Among Deployed Personnel (n = 31,152), Millennium Cohort Study, United States, 2001–2013
| Characteristics | Mena (n = 23,797) | Womena (n = 7,355) | ||||||
|---|---|---|---|---|---|---|---|---|
| No. | New-Onset Asthma, % | RR | 95% CI | No. | New-Onset Asthma, % | RR | 95% CI | |
| Multiple deploymentsb,c | ||||||||
| Yes | 6,452 | 2.1 | 0.99 | 0.82, 1.20 | 1,442 | 3.3 | 0.95 | 0.70, 1.28 |
| No | 17,345 | 2.4 | 1.00 | Referent | 5,913 | 3.8 | 1.00 | Referent |
| Deployment durationb,d | ||||||||
| 1–200 days | 10,231 | 2.1 | 1.00 | Referent | 3,555 | 3.4 | 1.00 | Referent |
| 201–400 days | 9,521 | 2.4 | 1.08 | 0.88, 1.32 | 2,979 | 4.3 | 1.16 | 0.89, 1.53 |
| 401–600 days | 2,683 | 2.8 | 1.35 | 1.02, 1.78 | 575 | 2.3 | 0.71 | 0.41, 1.22 |
| >600 days | 1,362 | 1.8 | 0.91 | 0.59, 1.37 | 246 | 4.5 | 1.54 | 0.85, 2.80 |
Abbreviations: CI, confidence interval; PTSD, posttraumatic stress disorder; RR, relative risk.
a Models were fitted separately for men and women. Both models mutually adjusted for race/ethnicity, birth year, marital status, education, body mass index, panel, service branch, service component, occupation, pay grade, separation from the military, and prior deployment to Bosnia, Kosovo, or Southwest Asia between January 1, 1998, and September 1, 2001; smoking status, occupational hazards requiring protective equipment, routine skin contact with paints/solvents/substances, and exposure to pesticides, including creams, sprays, and uniform treatments, and pesticides applied in the environment/surroundings; life stressor events; and PTSD.
b Separate models were fitted for multiple deployments and deployment duration.
c Multiple deployments were defined as deploying in support of Operation Iraqi Freedom or Operation Enduring Freedom more than once during the follow-up period.
d Deployment duration was defined as the cumulative number of days deployed in support of Operation Iraqi Freedom or Operation Enduring Freedom during the follow-up period.