Association of Changes in Hand Pain With BMI, Employment, and Mental Well-Being Over Four Years in Patients With Hand Osteoarthritis.

Objective: We aimed to characterize patients with hand osteoarthritis (OA) with deteriorating or improving hand pain and to investigate patients achieving good clinical outcome after four years.

Methods: We used four-year annual Australian/Canadian Hand Osteoarthritis Index (AUSCAN) pain subscale (range 0-20) measurements from the Hand OSTeoArthritis in Secondary Care cohort (patients with hand OA). Pain changes were categorized as deterioration, stable, and improvement using the Minimal Clinical Important Improvement. Good clinical outcome was categorized using the Patient Acceptable Symptom State (PASS). Associations between baseline characteristics (patient and disease characteristics, coping styles, and illness perceptions) and outcomes were investigated using multinomial or binary logistic regression, adjusted for baseline pain, age, sex, and body mass index (BMI).

Results: A total of 356 patients (83% female, mean age 60.6 years, mean AUSCAN score 9.1) were analyzed. Pain improved for 38% of patients, deteriorated for 30% of patients, and remained stable for 32% of patients over four years. Four-year pain development followed annual trends. At baseline, 44% of patients reached PASS, and 49% of patients reached PASS at follow-up. Higher BMI, coping through comforting cognitions, and illness comprehension were positively associated with pain deterioration. Higher AUSCAN function score, mental well-being, and illness consequences were negatively associated with pain improvement. Employment (positive) and emotional representations (negative) were associated with both improvement and deterioration. Higher baseline AUSCAN function, tender joint count, and symptoms attributed to hand OA were associated negatively with PASS after four years.

Conclusion: The pain course of patients with hand OA is variable, not inevitably worsening, and various factors may play a role. Whether modification of these risk factors can influence pain outcomes requires further investigation.