Validation and reliability of the Turkish version of the Pain disability index

The purpose of the present study was to adapt the Pain Disability Index (PDI) to Turkish population and assess the reliability and validity of the adapted Turkish version. In this regard, 151 patients who were admitted to our outpatient clinic with symptomatic knee OA was included in our study. The diagnosis of OA was based on the American College of Rheumatology (ACR) criteria. The sociodemographic features of the patients have been determined. Detailed physical examinations of the all patients were done by the same Physical Medicine and Rehabilitation doctor. The knee x-ray?s of the patients were evaluated with the Kellgren- Lawrence grading system. The pain severity at rest, in motion and at physical examination was determined by using visual analogue scale. All the participants have read and filled out the PDI, the WOMAC, and the SF-36 under the same doctor supervision. To show test-retest reliability, 103 of the participants were tested again with the adapted Turkish version of the PDI, 5 days later. The reliability of the adapted version was excellent with high internal consistency and test-retest reliability. In the analysis for validity, a high correlation between the similar sub-scales of both the SF-36 and the WOMAC to the PDI was found. In conclusion, the present study indicates that Turkish version of the PDI is highly reliable and valid.