Characterizing Treatment Credibility, Treatment Expectancy, and Symptom Expectancy in Patients Before Nonoperative Treatment for Degenerative Meniscal Tears.

Background: The role of nonspecific factors, such as treatment credibility, treatment expectancy, and symptom expectancy, may shape the outcomes of the nonoperative treatment of degenerative meniscal tears (DMTs).

Purpose/hypothesis: The purpose of this study was to characterize treatment credibility and expectancy, symptom expectancy, and patient and clinical correlates of these factors among participants before undergoing 4 nonoperative treatment programs for DMTs. It was hypothesized that (1) treatment credibility scores would be similar across patient and baseline clinical subgroups and (2) treatment expectancy and symptom expectancy scores would be lower in older patients and among those reporting a longer pain duration or greater pain intensity.

Study Design: Cohort study; Level of evidence, 3.

Methods: In 126 participants, validated scales were administered before treatment to assess the credibility of the assigned treatment (possible score of 1-9) as well as the expectations of treatment outcomes (0-100) and symptom improvement (1-5). Patient and clinical characteristics associated with these variables were examined.

Results: On average, participants (mean age, 58 years [range, 45-75 years]; 51% female; 94% White) expected the treatment to improve their symptoms by a mean of 68% and expected their symptoms to be "very likely" to improve. Participants with a body mass index (BMI) ≥30 kg/m had lower mean treatment credibility (6.09 ± 1.81) and treatment expectancy (64.53 ± 25.16) scores on bivariate analyses than those with a BMI <30 kg/m (6.73 ± 1.69 [ = .045] and 72.86 ± 19.20 [ = .039], respectively). Participants reporting a pain duration ≥3 months also had lower mean treatment expectancy (63.85 ± 23.83) and symptom expectancy (3.70 ± 0.85) scores compared to those reporting a pain duration <3 months (75.52 ± 18.93 [ = .003] and 4.16 ± 0.67 [ = .001], respectively).

Conclusion: Most patients about to undergo physical therapy for DMTs considered it to be between "somewhat" and "very" credible and believed that their symptoms, on average, were "very likely" to improve. Although not supported by most evidence, patients with a BMI ≥30 kg/m believed physical therapy to be less credible and had lower treatment and symptom expectations, and those with symptoms present for ≥3 months had lower treatment and symptom expectations as well. Whether these nonspecific factors influence outcomes should be considered for further research.