Cross-Sectional Contrast Between Individuals With Foot/Ankle vs Knee Osteoarthritis for Obesity and Low Education on Health-Related Quality of Life.

Background: Improving health-related quality of life (HRQoL) necessitates an understanding of the influence of patient characteristics on, and interrelationship among, HRQoL domains. In osteoarthritis (OA), these associations have predominantly been examined in hip/knee populations. We investigated whether there were differences in these associations between foot/ankle and knee OA samples.

Methods: Individuals seeking orthopedic care for foot/ankle or knee OA completed a questionnaire pre-consultation, including HRQoL domains (bodily pain [BP], physical [PF] and social functioning [SF], and mental [MH] and general health [GH]), obesity, comorbidity, and sociodemographic characteristics. Associations were examined via stratified path analysis (foot/ankle vs knee). Foot/ankle: n = 180, mean age = 55 (range: 25 to 82), 52% female. Knee: n = 253, mean age = 62 (range: 26 to 92), 51% female.

Results: The interrelationship among HRQoL domains was generally similar between groups. However, the influence of patient characteristics differed. Low educational status was associated with worse scores for GH, MH, and SF in the foot/ankle group, whereas no significant effects were found in the knee group. Obesity was associated with worse scores for SF, BP, and GH in the foot/ankle compared to the knee group. Patient characteristics explained considerably more of the variation in domain scores in the foot/ankle group.

Conclusion: There are significant differences in the impact of patient characteristics on HRQoL domains in foot/ankle versus knee OA patients. Therefore, a universal approach to patient education/intervention to improve HRQoL in lower-extremity OA is not likely to achieve optimal results. Based on these findings, we recommend joint-specific patient education, with a particular emphasis on patient characteristics among the foot/ankle OA population.

Level Of Evidence: Level III, retrospective comparative study.