Validation of the functional rating index for the assessment of athletes with neck pain

Aim: To validate the culturally-adapted Persian Functional Rating Index (PFRI) for assessing neck pain (NP) in athletes.

Methods: In this cross-sectional study, 100 athletes with NP and 50 healthy athletes participated and responded to the PFRI. Fifty athletes with NP completed the PFRI for at least 7 d later to establish test-retest reliability.

Results: The athletes with NP responded to all items, indicating excellent clinical utility. No floor and ceiling effects were found, indicating content validity and responsiveness. The PFRI revealed capability to discriminate between the athletes with NP and healthy athletes. The PFRI demonstrated strong correlation with the Numerical Rating Scale (Spearman's rho = 0.94), and the Persian Neck Disability Index (Pearson r = 0.995), supporting criterion and construct validity. Internal consistency reliability was high (Cronbach's α coefficient: 0.97). The test-retest reliability was excellent (ICCagreement = 0.96). The absolute reliability values of standard error of measurement and smallest detectable change were 3.2 and 8.84, respectively. An exploratory factor analysis yielded one factor explaining 78.03% of the total variance.

Conclusion: The PFRI is a valid and reliable measure of functional status in athletes with NP.