Abstract
Introduction
Within the field of arthroplasty, the use of patient-reported outcome measures (PROMs) is becoming increasingly ubiquitous in an effort to employ more patient-centered methods of evaluating success. PROMs may be used to assess general health, joint-specific pain or function, or mental health. General and joint-specific questionnaires are most often used in arthroplasty research, but the relationship between arthroplasty and mental health is less well understood. Furthermore, longitudinal reports of PROM changes after arthroplasty are lacking in the literature.
Our primary aim was to quantify the improvement in general, joint-specific, and mental health PROMs following total hip arthroplasty (THA) as well as the extent of any deterioration through the 7 years follow-up. Our secondary aim was to identify predictors of clinically significant PROM decline.
Methods
A total of 864 patients from 17 centers across 8 countries were enrolled into a prospective study. Patients were treated with components from a single manufacturer, which have been shown to be well-functioning in other studies.
Patients completed a battery of PROMs preoperatively, and at one, three, five, and seven years post-THA. Changes in PROMs between study visits were assessed via paired tests.
Postoperative trends for each PROM were determined for each subject by the slope of the best-fit line of the four postoperative data points. Significant PROM deterioration was defined as one literature-defined minimum clinically important difference over 5-years. Binary logistic regressions were used to identify independent predictors of significant decline in the EuroQol (EQ-5D) visual analogue scale (VAS) for Health State, 36-Item Short Form Survey (SF-36) physical composite summary (PCS), and SF-36 mental composite summary (MCS).
Results
A total of 417 completed all study visits (70% of currently eligible). All patients experienced significant improvements in all hip-specific and most general health PROMs 1-year post-THA (all p ≤ 0.002). In addition, a significant number of patients experienced a reduction in anxiety/depression following THA (p < 0.001). Hip specific PROMs remained excellent through 7-years, but most general and mental health PROs declined by the 7-year visit.
A total of 133 patients (32%) experienced significant deterioration in the EQ-5D Health State. Age greater than 60 years (odds ratio (OR) = 1.9; p = 0.002) and obesity (OR = 1.7; p = 0.036) were independently predictive of EQ-5D Health State decline.
A total of 58 patients (14%) experienced significant deterioration in the SF-36 PCS. Independent predictors of significant SF-36 PCS decline were lower preoperative SF-36 MCS (OR = 0.9; p = 0.002) and obesity (OR = 2.6; p = 0.009).
A total of 229 patients (55%) experienced significant deterioration in the SF-36 MCS. Age greater than 60 years was predictive of significant SF-36 MCS decline (OR = 1.8; p = 0.017).
Conclusion
For most patients, hip-specific PROMs will remain near the 1-year level through 7-years follow-up. Except for those with lower preoperative mental health or with obesity, gauging a patient's hip-related status at 1-year is sufficient to extrapolate their trajectory through midterm follow-up.
Some patients experience mental health improvements following THA, but the majority experience a decline within 7 years of their surgery, especially older patients. Similarly, age-related decreases in general health are expected, following initial improvement 1 year after THA. Obese patients are also more likely to experience general health deterioration post-THA.
By addressing the modifiable risk factors for PROM decline, the positive effects of THA may be better sustained over time.
