Categories of the Patient-Specific Functional Scale Activities in Chronic Neck Pain and Their Relationship to the Neck Disability Index

Intoduction: Common outcome measures for chronic neck pain are the Patient-Specific Functional Scale (PSFS) and the neck disability index (NDI). The primary aim was to categorize the top-rated, patient-selected functional activity limitations of the PSFS to determine if there were consistent limited functional activities for individuals with chronic neck pain and how these compared to the constructs of activities on the NDI. The secondary aim was to determine the relationship between scores for individuals who completed both the NDI and PSFS. Design: A retrospective review of data extracted from the electronic medical record, EPIC, within two hospital-based outpatient physical therapy clinics within a health care system. Methods: Retrospective analysis was performed on individual's characteristics, self-selected functional activity limitations, and total scores of the PSFS and NDI. Most common categories of self-selected functional activity limitations were developed by practicing physical therapists. These functional activity limitation categories of the PSFS were compared to the activities of the NDI. Mean PSFS total scores were correlated with the NDI total scores with Spearman's test. Results: Participants were individuals with chronic neck pain from January 2013-September 2018 (n=2283). Movement-based activities accounted for 60.8% of the functional activity limitations of the PSFS with the top functional activity limitations being cervical motion and exercise (32%). The PSFS total score moderately correlated with NDI (r=-0.50, p=<0.01) which may relate to the differences in constructs of the NDI and the top patient-selected PSFS functional activity limitations found in this analysis. Conclusion: The results suggest that individuals with chronic neck pain present with similar categories of self-selected functional activity limitations that differ from activities of the NDI. Additional research is needed to improve outcome measures to capture patient-selected functional activity limitations and an individual's pain experience.