Association between multimorbidity and quality of life after hip replacement surgery: analysis of routinely collected patient-reported outcomes.

Background: Total hip replacement surgery is performed to improve quality of life (QoL). We explored the association between multimorbidity and change in QoL after total hip replacement.

Methods: Analysis of patients included in the NHS England hip replacement Patient Reported Outcome Measures (PROMs) database with complete preoperative from 3 to 6 months postoperative EQ-5D QoL data from April 2013 to March 2018. Multimorbidity was defined as two or more chronic diseases excluding arthritis. The primary outcome measure was change in QoL using the Pareto Classification of Health Change. We compared QoL change for patients with and without multimorbidity and those with no multimorbidity using multivariable modelling. Data are presented as odds ratio (OR) with 95% confidence interval or n (%).

Results: Of 216,191 patients, we included 178,129 (82.4%) patients with complete data. Most patients 63,327 (35.6%) were 70-79 yr of age, and 98,513 (55.3%) were women. Multimorbidity was present in 38,384 patients (21.6%). QoL improved after surgery for 149,774 (84.1%) patients, remained unchanged for 10,219 (5.7%) patients, and became worse after surgery for 7289 (4.1%) patients. QoL changes were mixed (at least one QoL domain improved and at least one deteriorated) for 10,847 (6.1%) patients. Poor QoL outcomes (unchanged/mixed/worse) were more likely for patients with multimorbidity (OR 1.53 [1.49-1.58]).

Conclusions: Hip replacement surgery improves QoL. However, patients with multimorbidity are less likely to experience these benefits. Poor QoL outcomes became more frequent as the number of comorbid diseases increased. These data should inform shared decision-making conversations around joint replacement surgery.