What Is the Association between Sex and Self-Perceived Health Status When Controlling for Disease-Specific Conditions? an Analysis of Pre- and Post-Operative EQ-5D-5L Differences in Total Hip and Knee Arthroplasty

OBJECTIVES:

Total hip and knee arthroplasty (THA and TKA) provide effective relief for patients with osteoarthritis to increase functionality of the joint and reduce pain. Although both are standardized treatments, multiple studies reported that pre-operative and sometimes post-operative self-perceived health status differ by sex. The health status can be measured by patient-reported outcomes (PROs) such as the EQ-5D-5L. This study investigates whether one single index score of the instrument should be used for both sexes to compare outcomes after undergoing THA and TKA.

METHODS:

Routine- and PROM-data of patients who submitted for elective primary THA or TKA in two German hospitals between 2016 and 2018 were analyzed. Thereby, 2368 THA patients (m=978; f=1,390) and 1629 TKA patients (m=715; f=914) were considered. Univariate analysis with Pearson’s chi-square was conducted to identify control variables for sex to avoid omitted-variable bias. To quantify the association between sex and the EQ-5D-5L dimensions, a cumulative odds ordinal logistic regression with proportional odds was conducted.

RESULTS:

For THA and TKA, both sexes recorded a clear improvement in health status post-surgery. When investigating the individual EQ-5D-5L dimensions, men indicated significantly better scores in the dimensions of “pain/discomfort” (TKA) and “anxiety/depression” (THA and TKA). Nevertheless, women achieve better scores in the dimension of “self-care” pre- and post-surgery (THA and TKA), while in THA post-operative “mobility” is also significantly associated with women.

CONCLUSIONS:

Our results confirmed that the self-perceived health status significantly improves after surgery for both treatments. However, due to the different associations of sex to the individual dimensions of the EQ-5D-5L, the weighted index score does not allow for comparison between sex in patients undergoing THA or TKA. Therefore, we argue to use the individual five dimensions for health status analysis, as they reveal relevant information on improvement over time which is not visible in the index score.