Prognostic factors associated with improvements in patient-reported outcomes in idiopathic adhesive capsulitis

BACKGROUND: The purpose of this study was to identify prognostic factors that are associated with improvements in patient-reported outcomes measures (PROMs) related to upper extremity function and pain in those suffering from idiopathic adhesive capsulitis. METHODS: All patients treated conservatively for primary idiopathic adhesive capsulitis were identified from our institutional database between 2019 and 2021. Exclusion criteria included any patients treated surgically, follow-up less than one year, or incomplete survey results. PROMs including Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Computer Adaptive Test Version 2.0 (P-UE), Pain Interference (P-Interference), Pain Intensity (P-Intensity), and visual analog scale (VAS) pain scores. They were obtained at initial consultation and at one year to assess patient-perceived impact of their condition. Multiple linear and multivariable logistic regressions were performed to identify factors associated with improvement in patient-perceived pain and shoulder function using final PROM scores and difference in PROM scores from initial consultation. An independent t-test was used to compare baseline and one-year minimum follow-up PROMs. Odds ratios and their 95% confidence intervals were calculated for each factor; a P value of < .05 was considered statistically significant. RESULTS: A total of 56 patients (40 females and 16 males) were enrolled in the study with an average age of 54.7 ± 7.7 years. A significant improvement (P < .001) was demonstrated at one-year minimum outcomes for P-UE, P-Interference, P-Intensity, and VAS scores. With respect to comorbid conditions, hypothyroidism [P-UE (β: 9.57, P = .006)] was associated with greater improvements in PROMs, while hyperlipidemia [P-UE (β: −4.13, P = .01) and P-Intensity (β: 2.40, P = .02)] and anxiety [P-UE (β: −4.13, P = .03)] were associated with poorer reported changes in PROMs. Female sex [P-UE (β: 4.03, P = .007) and P-Interference (β: −2.65, P = .04)] and employment in manual labor professions [P-Interference (β: −3.07, P = .01), P-Intensity (β: −2.92, P = .006), and VAS (β: −0.66, P = .03)] were associated with significantly better patient-perceived outcomes. Hispanic heritage was associated with higher reported changes of P-Intensity (β: 8.45, P = .004) and VAS (β: 2.65, P = .002). CONCLUSION: Patient-perceived improvements in PROMIS score during the natural history of adhesive capsulitis are likely multifactorial, with anxiety, hyperlipidemia, increased body mass index, and Hispanic heritage associated with reduced improvement in PROMIS scores.