Prediction of Persistent Musculoskeletal Pain at 12 Months: A Secondary Analysis of the Optimal Screening for Prediction of Referral and Outcome (OSPRO) Validation Cohort Study.

Background: Musculoskeletal pain is a societal epidemic because it is highly prevalent and a leading contributor to disability; however, physical therapists are still challenged when predicting which patients are at high risk for persistent symptoms.

Objective: The objectives of this study were to identify patient characteristics predictive of persistent musculoskeletal pain 12 months following physical therapist care and to determine the influence of anatomical region.

Design: The design included a secondary analysis of a cohort study.

Methods: Participants ranged in age from 18 to 65 years, had a primary report of knee, shoulder, back, or neck pain, were receiving physical therapy, and were enrolled in the Orthopedic Physical Therapy Investigative Network (OPT-IN) Optimal Screening for Prediction of Referral and Outcome (OSPRO) validation cohort study. Candidate predictor variables included demographic and clinical characteristics, comorbidities, and OSPRO Review of Systems (OSPRO-ROS) and OSPRO Yellow Flag (OSPRO-YF) tool scores. Persistent musculoskeletal pain was assessed by self-report responses to questions on the duration of pain and activity limitation. Logistic regression was used for completed cases to identify predictors of persistent pain at 12 months in full and parsimonious models.

Results: Follow-up assessment at 12 months was performed for 63.4% of participants (279/440). Participants with persistent pain at 12 months (n = 101; 36.2%) had more comorbidities, higher numerical pain rating scale scores, and higher OSPRO-ROS and OSPRO-YF tool scores at baseline than those without persistent pain, and the findings were independent of anatomical region. The number of comorbidities (odds ratio [OR] range = 0.30-0.46), numerical pain rating scale scores (OR at baseline = 1.44-1.75; OR at 4 weeks = 1.37-1.39), and OSPRO-ROS (plus additional items) scores (OR = 1.33-1.54) were predictors in full and parsimonious models.

Limitations: Convenience sampling was used, with a follow-up rate at 12 months (63.4%) that was lower than anticipated, and an operational definition for chronic low back pain was applied to persistent musculoskeletal pain in other body regions.

Conclusions: The OSPRO-ROS tool may be used to improve the prediction of persistent musculoskeletal pain at 12 months in conjunction with comorbidities and pain intensity (baseline and 4 weeks). These are potentially important findings because persistent pain was not commonly evaluated in previous screening studies; however, it is a relevant outcome in an era of front-line nonpharmacological pain management.