Prevalence and impact of pain in multiple sclerosis: physical and psychologic contributors

Abstract

Objective: To characterize the prevalence and impact of pain in veterans with multiple sclerosis (MS) and to assess their association with demographic, biologic, and psychologic variables.

Design: Cross-sectional cohort study linking computerized medical record information to mailed survey data.

Setting: Veterans Health Administration (VHA).

Participants: Sixty-four percent (2994/4685) of veterans with MS who received services in VHA and also returned survey questionnaires.

Interventions: Not applicable.

Main outcome measures: Items assessing pain intensity, pain interference, and physical and mental health functioning.

Results: Ninety-two percent of participants reported bodily pain within the prior 4 weeks, with 69% of the total sample indicating pain of moderate or higher intensity. Eighty-five percent indicated that pain caused functional interference during the past 4 weeks, with 71% of the total sample reporting pain-related interference that was moderate or greater. No significant sex or race differences emerged for the pain indices. A significant but modest relationship between increasing age and pain interference emerged (r=.05, P<.01); however, age was not significantly related to pain intensity. Multivariate regression analyses identified pain intensity (beta=.73), physical health functioning (beta=-.07), and mental health functioning (beta=-.13) variables as significant, unique contributors to the prediction of pain interference. The interaction of pain intensity and physical functioning was also significant but of minimal effect size (beta=-.03).

Conclusions: Pain is highly prevalent and causes substantial interference in the lives of veterans with MS. The functional impact of pain in veterans with MS is influenced by pain intensity, physical health, and emotional functioning. Clinical practice should take each of these domains into consideration and reflect a biopsychosocial conceptualization.