The effect of medical comorbidity on HOOS/KOOS/FAOS: a national register-based cohort study of 7850 representative citizens.

OBJECTIVES

Despite extensive validation, the impact of medical comorbidities on the outcomes of the Hip Disability and Osteoarthritis Outcome Score (HOOS), Knee Injury Osteoarthritis Outcome Score (KOOS), and Foot and Ankle Outcome Score (FAOS) remains underexplored. This study aimed to evaluate the effect of medical comorbidities on HOOS, KOOS, and FAOS subscales using a large, nationally representative sample.

METHODS

This national register-based cohort study invited 26,877 participants to complete HOOS, KOOS, or FAOS questionnaires. Medical comorbidities-including diabetes, chronic obstructive pulmonary disease/asthma, rheumatological diseases, osteoporosis, stroke, obesity, and heart disease-were identified through the Danish National Patient Register.

RESULTS

A total of 7850 participants (29%) responded, with 1863 (24%) having medical comorbidities. HOOS/KOOS/FAOS subscale scores were significantly worse in patients with comorbidities, particularly in the Sport/Rec, ADL, and QOL subscales. Mean score differences between participants with and without comorbidities were pain (- 5.7, 95% CI - 6.6 to - 4.7), symptoms (- 4.6, 95% CI - 5.5 to - 3.6), ADL (- 7.1, 95% CI - 8.0 to - 6.1), Sport/Rec (- 10.4, 95% CI - 11.9 to - 8.9), and QOL (- 6.9, 95% CI - 8.2 to - 5.7). Diabetes, rheumatological diseases, and obesity were associated with the greatest complaints.

CONCLUSION

Patients with medical comorbidity reported significantly lower HOOS/KOOS/FAOS subscale scores compared to participants without medical comorbidity. Diabetes, chronic rheumatological diseases, and adiposities were observed with the most complaints. Key Points • Medical comorbidity predicts considerably lower HOOS/KOOS/FAOS subscale scores. • Diabetes, rheumatological diseases, and obesity exerted the most pronounced negative effects on the HOOS/KOOS/FAOS. • Findings underscore the importance of considering comorbidities when interpreting HOOS/KOOS/FOAS subscale scores.