Functional index for hand osteoarthritis (FIHOA) is associated with pain, muscle strength, and EQ-5D in hand osteoarthritis

ABSTRACT

Abstract Background: This study identified whether Functional Index for Hand Osteoarthritis (FIHOA) is associated with pain, hand muscle strength, health-related quality of life, and radiographic severity in hand osteoarthritis (OA). Methods: We consecutively recruited 95 patients with hand OA. The FIHOA was used to assess questionnaire-based physical function in hand OA. Health-related quality of life was evaluated using EuroQol-5 dimension (EQ-5D). Radiographic changes of hand joints were measured by Kellgren-Lawrence (K-L) grade, which was determined based on total radiographic severity score and number of affected joints. Other measures included patient's visual analogue scale (VAS) score for pain and performance-based function indexes such as grip and pinch strength. Statistical analysis was performed using Mann-Whitney U test, Spearman's correlation analysis, and multivariate logistic regression analysis. Results: FIHOA score was negatively associated with grip and pinch hand strength and EQ-5D and positively correlated to VAS pain (p < 0.05 for all). There were significant differences of grip and pinch strength, VAS pain, EQ-5D index, and EQ-VAS between two FIHOA groups (≤ 4 vs. > 4) (p < 0.05 for all). Multivariate logistic regression analysis showed that higher FIHOA score (FIHOA > 4) was related with increased VAS pain and with lower EQ-5D index (p = 0.008 and p = 0.013, respectively). There was no association between FIHOA score and measures of total radiographic severity score and number of affected joints. Conclusion: This study observes that FIHOA score is associated with patient-reported VAS pain, hand muscle strength indexes, and EQ-5D but not radiographic severity in hand OA.