Purpose: We examined associations between self-reported and clinician-assessed comorbidity and quality of life (QOL) outcomes after hip and knee replacement.
Methods: This is a cross-sectional, questionnaire-based national survey. Participants aged 45 years or older (n = 409) were recruited from the New Zealand Joint Registry six months after a total hip (THR), total knee (TKR) or unicompartmental knee replacement (UKR). The main outcome QOL was measured using an 8-item short form of the World Health Organisation Quality of Life (WHOQOL-Bref) questionnaire six months following joint replacement surgery. The WHOQOL is a generic and non-health condition specific measure of QOL.
Results: Participants were on average 68 years of age, with more men (54%) than women (46%). Number of coexisting conditions and body mass index were correlated with age, pain and function scores, and QOL (p < 0.01), but not with each other. Linear regression analyses showed that comorbidities such as number of comorbid conditions and BMI had moderate associations with QOL outcomes.
Conclusion: This study showed that general QOL outcomes following hip and knee joint replacement, while generally high, were associated with comorbidity burden and BMI. Future prospective research examining change in QOL before and following surgery would help to advance understandings of the various factors that contribute to patient satisfaction with their joint replacement.
Keywords: Comorbidity; EUROHIS-QOL; Quality of life outcomes; Total hip replacement; Total knee replacement; Unicompartmental knee replacement.