Association of Pain With Physical Function, Depressive Symptoms, Fatigue, and Sleep Quality Among Veteran and non-Veteran Postmenopausal Women

Purpose of study: To characterize the prevalence and longitudinal effects of pain in older Veteran and non-Veteran women.

Design and methods: Data on 144,956 participants in the Women's Health Initiative were analyzed. At baseline, Veteran status, pain severity, and pain interference with activity were assessed. Outcomes of physical function, depressive symptoms, fatigue, and sleep quality were reported at baseline by all study participants and longitudinally on two follow-up occasions (3 years and 13-18 years after baseline) in the observational study participants (n = 87,336).

Results: At baseline, a total of 3,687 (2.5%) had a history of military service and 22,813 (15.8%) reported that pain limited their activity level moderately to extremely during the past 4 weeks. Prevalence of pain interference did not differ in Veterans and non-Veterans (16.8% and 15.7%, respectively; p= .09). At baseline, women with moderate-to-extreme pain interference had substantially worse physical function and greater symptoms of depression, fatigue, and insomnia than those with less pain (p < .001 for all comparisons), adjusting for several social, behavioral, and health related factors. There were no significant military service by pain interference interactions for any of the outcomes (p > .2), indicating that the effect of pain interference on outcomes at baseline did not vary between Veterans and non-Veterans. Moderate-to-extreme pain interference was associated with a greater rate of decline in physical function over time (p < .001) and higher incidence of limited physical functioning (p < .001), but these effects did not vary by Veteran status. Similar results were observed with pain severity as the exposure variable.

Implications: As the Veteran population ages and the number of women exposed to combat operations grows, there will be an increased need for health care services that address not only pain severity and interference but also other disabling comorbid symptoms.