Background: The Subgrouping for Targeted Treatment (STarT) musculoskeletal (MSK) tool stratifies patients with MSK disorders (MSDs) into prognostic categories based on poor outcomes.
Purpose: This study aimed at investigating the validity and reliability of the Persian STarT MSK tool in people suffering from painful MSDs in Iran.
Methods: A total of 593 subjects with painful MSDs including neck, shoulder, low back, knee, and multisite pain received and completed the STarT MSK tool, visual analog scale (VAS), EuroQol five-dimensions three-levels questionnaire (EQ-5D-3 L), short form-36 health survey questionnaire (SF-36), and Örebro musculoskeletal pain screening questionnaire (ÖMPSQ) in the first visit. To examine test-retest reliability, 234 patients completed the STarT MSK tool 2 days after the initial visit.
Results: In this study, 139 (23.5%), 266 (44.9%), and 188 (31.7%) participants were classified as low-, medium-, and high-risk groupings for poor outcomes, respectively. Spearman's correlation coefficient showed a strong relationship among Persian STarT MSK tool and EQ-5D-3 L (-0.78), SF-36 (-0.76), and OMPSQ (0.70). The results of known-group validity indicated that this tool could distinguish among the participants in different risk subgroups based on the scores of the ÖMPSQ, VAS, SF36, and EQ-5D-5 L (p < .001). No ceiling and floor effects were observed. Cronbach's alpha and intra-class correlation coefficient (ICC2,1) were acceptable (0.71) and excellent (0.98), respectively.
Conclusion: The Persian version of STarT MSK tool has shown to be a valid and reliable instrument to stratify people with painful MSDs into low-, medium-, and high-risk subgroups based on persistent pain disability.
Keywords: Pain; reliability; stratification; translation; validity.