Pain and functioning in persons with post-polio syndrome (PPS): Independent effects on functioning

Introduction: Pain and fatigue are common in persons with PPS and may contribute to dysfunction in this population. The tendency for PPS symptoms to start in middle age and then worsen suggests chronological age may also be associated with increases in dysfunction due to these symptoms.

Methods: Participants were 446 persons (75.3% female) with PPS who participated in an ongoing survey investigating secondary conditions of people aging with a physical disability. Measures included average pain intensity and fatigue (0-10 numerical scale), psychological dysfunction (PHQ-9), and physical functioning (PROMIS Physical Functioning short form)

Results: Analyses confirmed the hypothesis that pain and fatigue, in addition to chronological age, make independent contributions to the prediction of physical and psychological dysfunction (all ps < 0.01). Regarding physical dysfunction, age accounted for 4% of the variance, while pain and fatigue accounted for an additional 9%. For psychological dysfunction, age accounted for 3% of the variance, with pain and fatigue accounting for an additional 18%. Moreover, a significant Age-x-Pain interaction emerged, with middle-aged patients reporting a stronger pain-depression relationship than older and elderly patients.

Discussion: Pain and fatigue independently contribute to physical and psychological functioning in persons with PPS. Furthermore, older age predicts worse physical functioning and less depression, while middle-aged individuals report greater impact of pain on depression than older and elderly persons with PPS. The findings support the importance of assessing and treating both pain and fatigue in persons with PPS to determine the extent to which this may improve quality of life.