Headache diagnoses among Iraq and Afghanistan war veterans enrolled in VA: a gender comparison.

OBJECTIVE: To examine the prevalence and correlates of headache diagnoses, by gender, among Iraq and Afghanistan War Veterans who use Department of Veterans Affairs (VA) health care.

BACKGROUND: Understanding the health care needs of recent Veterans, and how these needs differ between women and men, is a priority for the VA. The potential for a large burden of headache disorders among Veterans seeking VA services exists but has not been examined in a representative sample.

METHODS: We conducted a historical cohort study using national VA inpatient and outpatient data from fiscal year 2011. Participants were all (n = 470,215) Iraq and Afghanistan War Veteran VA users in 2011; nearly 13% were women. We identified headache diagnoses using International Classification of Diseases (ICD-9) diagnosis codes assigned during one or more VA inpatient or outpatient encounters. Descriptive analyses included frequencies of patient characteristics, prevalence and types of headache diagnoses, and prevalence of comorbid diagnoses. Prevalence ratios (PR) with 95% confidence intervals (CI) were used to estimate associations between gender and headache diagnoses. Multivariate models adjusted for age and race. Additional models also adjusted for comorbid diagnoses.

RESULTS: In 2011, 56,300 (11.9%) Veterans received a headache-related diagnosis. While controlling for age and race, headache diagnoses were 1.61 times more prevalent (95% CI = 1.58-1.64) among women (18%) than men (11%). Most of this difference was associated with migraine diagnoses, which were 2.66 times more prevalent (95% CI = 2.59-2.73) among women. Cluster and post-traumatic headache diagnoses were less prevalent in women than in men. These patterns remained the same when also controlling for comorbid diagnoses, which were common among both women and men with headache diagnoses. The most prevalent comorbid diagnoses examined were depression (46% of women with headache diagnoses vs 40% of men), post-traumatic stress disorder (38% vs 58%), and back pain (38% vs 46%).

CONCLUSIONS: Results of this study have implications for the delivery of post-deployment health services to Iraq and Afghanistan War Veterans. Migraine and other headache diagnoses are common among Veterans, particularly women, and tend to occur in combination with other post-deployment health conditions for which patients are being treated.