The Burden of Pain Associated with Osteoarthritis in the Hip or Knee from the Patient’s Perspective: A Multinational Cross-Sectional Study

INTRODUCTION: To evaluate, from the patient's perspective, the burden of pain associated with hip/knee osteoarthritis (OA) in the USA and selected European Union (EU) countries. METHODS: Data were drawn from the 2017 global Adelphi OA Disease Specific Programme™ (DSP). Patients with hip/knee OA were stratified based on pain intensity and the presence/absence of current opioid use. Outcomes included Western Ontario and McMaster Universities Osteoarthritis Index scores, functional limitations, unmet treatment needs, Charlson Comorbidity Index, relevant comorbid conditions, the 5-dimension 5-level EuroQol, and the Work Productivity and Activity Impairment Questionnaire: Specific Health Problem. Bivariate testing compared outcomes using patients with no/mild pain without opioid use as the reference group. RESULTS: The study population comprised 2170 patients (US: n = 623 [28.7%]; EU: n = 1547 [71.3%]) with knee (54.9%), hip (24.6%), or knee/hip (20.5%) OA. Mean (SD) age was 66.4 (11.2) years. Patients had no/mild pain without opioid use (39.6%), no/mild pain with opioid use (10.2%), moderate/severe pain without opioid use (30.6%), and moderate/severe pain with opioid use (19.7%). Compared with the reference group, patients with moderate/severe pain reported significantly (p < 0.05) higher functional limitations, greater use of ≥ 3 treatments and treatment dissatisfaction, reduced quality of life, and impaired work productivity and activity. The burden was highest with moderate/severe pain with opioid use. Results were generally similar in the US and EU cohorts. CONCLUSIONS: The results from this multinational cross-sectional study indicate that the impact of OA pain is multidimensional, worsened by increasing pain intensity, and may not be adequately addressed by current treatment strategies.