There exists a heavily investigated relationship between higher activity levels and improving symptoms of anxiety, depression, stress, and pain catastrophizing in general populations not severely limited by orthopedic pathology [3, 8, 9, 12, 14]. New interest has recently arisen in the impact of these psychological elements on the management of orthopedic patients [28]. Total joint arthroplasty candidates who report worse preoperative pain and subjective function screen higher for depression, anxiety, and pain catastrophizing [29]. Patients with chronic depressive symptoms, anxiety, or catastrophizing who undergo THA experience improvements in functional outcomes and pain postoperatively; however, these patients improve less than patients with negative psychological screenings [18–20]. Therefore, there is a potential opportunity to provide psychosocial interventions for THA patients to improve outcomes [30]. Although there is emerging literature about the relationships between depressive symptoms, anxiety, and catastrophizing with orthopedic pathology for subjective function and pain, there is a paucity of knowledge surrounding the relationship between psychological factors and activity level in total joint arthroplasty patients. Therefore, we sought to evaluate how preoperative to postoperative changes in depression, anxiety, and catastrophizing relate to changes in patient activity levels over the same interval.
Our findings showed significant improvements in all PCS subscales, HADS subscales, and DASS subscales along with statistically significant improvement in UCLA Activity Score at least one year following THA. Although statistically significant, the increase in UCLA Activity Score of 0.91 is less than the minimal clinically important difference (MCID) of 1 [31]. This suggests that patients may not notice improved activity levels postoperatively but still experience improved psychological screenings. All PCS subscales and the total score achieved a reduction greater than the MCID of 38% [32]. HADS subscales’ improvements also exceeded their MCID of 1.7 [33]. Improvements in DASS subscales did not achieve their MCID of 6.19 suggesting the scale may not be sensitive enough for the THA population [34]. The standard deviations of the aforementioned subscales were sizable in comparison to their relative to their respective means suggesting wide variation in patient responses. Non-parametric Wilcoxon Signed-rank tests were used to control for the lack of normal distributed responses. This may be caused by substantial amounts of the cohort that screened negative for PCS (22.3%), HADS (9.2%), and DASS (16.1%) at both the preoperative and follow-up times.
Our investigation of correlations between changes in PCS, HADS, and DASS subscales and UCLA Activity Score showed negative correlations for all subscales. The strongest negative correlations were between UCLA Activity Score and change in HADS anxiety, change in HADS depression, and change in DASS anxiety which were still weak [27]. The remaining subscales showed weak correlations to changes in activity level. Preoperatively inactive patients attain the greatest improvement in postoperative activity levels suggesting that inactive patients may also experience greater improvement in depression, anxiety, and catastrophizing screenings than preoperatively active patients [17]. Interestingly, the depression subscale for HADS displayed stronger correlations than the same respective DASS subscale to activity level change with similar correlations between the respective anxiety subscales. Therefore, HADS may have more value in THA patients when activity level is valued in treatment outcomes, especially as it contains fewer questions and elicited greater complete response rates (HADS 100% vs 68.2%). The lower DASS response rate was the main contributor to the underpowered analyses of its subscales. Overall, the results are transitively consistent with other studies which demonstrate a negative correlation between depression, anxiety, and catastrophizing severity with pain and function since physical function is also positively correlated with physical activity levels [17, 26, 28, 35, 36].
Our study contains multiple limitations. The primary limitations were a low overall response rate (~ 43%) and a proportionately low DASS response rate compared to valid follow-up surveys (~ 68%). One year follow-up was selected to provide an intermediate-term perspective; however, it does not elucidate when maximum improvements in depression, anxiety, or catastrophizing would be attained. Potential exists for additional short-term longitudinal studies to address this concern. Retrospective recall by the patient on the state of their well-being introduces memory biases that could overestimate factors such as activity level or skew psychological screenings [37, 38]. Since follow-up was not constrained with a maximum window in addition to the minimum window, results may contain exaggerated variations if patient-reported measures are dynamic after one year.