Comparing the validity of five participation instruments in persons with spinal conditions

Objective: To evaluate and compare the construct validity of 5 participation instruments developed using the International Classification of Functioning, Disability and Health (ICF). Methods: A total of 545 subjects diagnosed and treated for a spinal condition at an acute hospital were followed-up and consented to complete a questionnaire. Subjects completed 5 participation instruments (Impact on Participation and Autonomy (IPA), Keele Assessment of Participation (KAP), Participation Measure-Post Acute Care (PM-PAC), Participation Objective Participation Subjective (POPS), World Health Organization Disability Assessment Schedule II (WHODAS II)). In addition, each subject completed a health status instrument and a quality of life instrument. The dimensionality, convergent/discriminant validity and known-group validity of the participation instruments were assessed. Results: A confirmatory factor analysis of the facture structure for the IPA and PM-PAC demonstrated adequate model fit. For convergent/discriminant validity, correlations were generally higher among similar domains of the WHODASII, IPA, KAP and PM-PAC, and as expected the lowest correlations were observed with the objective domains of the POPS. Most instruments demonstrated known-group validity. Conclusion: Differences in the construct validity evidence of the POPS compared with the other 4 instruments were noted. To date, there is no gold standard for measuring participation, and clinicians and researchers should consider the type of information required prior to selecting an instrument. Journal Compilation