Psychological Factors, Central Sensitization, and Insomnia as Potential Prognostic Factors for Short-Term Pain and Disability in Patients With Frozen Shoulder: A Multicentric Prospective Single-Cohort Study.

backgroundIdentifying modifiable prognostic factors is essential for personalizing conservative interventions. Several psychological and systemic variables remain underexplored in the frozen shoulder (FS) population, particularly regarding their prognostic relevance for short-term changes in pain and disability.

aimTo estimate the prognostic value of psychological factors, central sensitization, and sleep disturbances in predicting clinical outcomes after 3 months of standardized conservative treatment.

methodThis multicenter, prospective cohort study was reported following the REMARK statement. Individuals were recruited between July and September 2025. Baseline demographic and clinical variables such as pain catastrophizing, state and trait anxiety, fear-avoidance beliefs (for Work and Physical Activity), central sensitization signs and symptoms, and insomnia were collected at baseline as potential prognostic factors. Shoulder pain and disability (measured with the SPADI subscores) served as outcome variables. Patients underwent a standardized multimodal conservative management for 3 months. Univariable and multivariable linear regression analyses were performed to examine associations between potential prognostic factors and SPADI pain and disability scores at 3-month follow-up.

resultsEighty participants were included. Trait anxiety emerged as the sole significant prognostic factor for shoulder pain (exp (β) = 1.21, 95% CI 1.06-1.38), while state anxiety significantly predicted disability (exp (β) = 0.83, 95% CI 0.73-0.95). The removal of outliers during sensitivity analysis eliminated the statistical significance of all potential prognostic factors when SPADI pain was the outcome. Regarding disability, however, state anxiety remained a significant prognostic factor (exp(β) = 0.86; 95% CI: 0.74-0.99). DISCUSSION AND

conclusionBaseline trait and state anxiety showed prognostic relevance for short-term pain and disability outcomes in patients with FS receiving conservative care. Pain catastrophizing, fear-avoidance behavior, central sensitization, and insomnia did not show significant associations in this cohort. These findings underscore the importance of incorporating psychological profiling, particularly anxiety assessment, into the clinical evaluation and prognostic reasoning for patients with FS.