The differential influence of pain and fatigue on physical performance and health status in ambulatory patients with human immunodeficiency virus

Objectives: The purposes of this study were to: 1) characterize physical performance in individuals with human immunodeficiency virus; and 2) examine group differences by pain and fatigue on a multivariate profile of disease, physical, and psychologic symptoms. Methods: One hundred outpatients, 78 men and 22 women (mean age 40.70 ± 7.49 years) participated. Patients completed a battery of physical performance tests in which the time taken or the distance reached or walked was measured. Self-report questionnaires included measures of pain (0-10 numerical rating scale), fatigue (Brief Fatigue Inventory), and perceived health status (Medical Outcomes Survey-HIV scale). Results: Physical performance was compromised in a task specific manner. Patients took twice as long as healthy individuals on a belt-tie and 4 times as long on a sit-to-stand task and in 6 minutes walked 75% of the distance covered by healthy individuals. Fifty percent of patients (n = 50) had pain at the time of testing (mean 6.3 ± 2.4), and 98% had fatigue (mean 5.4 ± 2.3). Multivariate analysis of variance showed pain had a greater influence on performance than fatigue. Pain, distance walked in 6 minutes, and unloaded forward reach accounted for 26% of the variability in quality of life (r = 0.51, P ≤ 0.0001). Discussion: Pain has a substantial impact on physical performance and quality of life among ambulatory human immunodeficiency virus patients. Fatigue also impacts physical performance. Compromised ability to perform certain physical tasks affects quality of life. Further investigation of the roles of these relevant variables should be investigated in path analyses.