Marcel W.M. Post, Luc P de Witte, Enid Reichrath, Manon M Verdonschot, Gert Jan Wijlhuizen, Rom JM Perenboom
DOI: 10.2340/16501977-0223

Objective: IMPACT-S is the screener part of the ICF Measure of Participation and ACTivities questionnaire. IMPACT-S consists of 33 items in 9 scales, reflecting the 9 activity and participation chapters of the International Classification of Functioning, Disability and Health (ICF). The reliability and validity of IMPACT-S as an independent brief measure of activities and participation was examined.
Design: Repeated administration of a postal questionnaire.
Patients: Road accident victims were recruited through several Dutch hospitals and rehabilitation centres. A total of 276 patients participated and 197 took part in both measurements.
Methods: Examination of test-retest reliability, reproducibility and construct validity. The World Health Organization Disability Assessment Schedule II (WHODAS-II) was included as criterion measure for concurrent validity.
Results: Types of main injury were fractures (38%), trauma?tic brain injury (37%), spinal cord injury (13%), whiplash (9%) and other (3%). Mean time after injury was 2. 2 years. Internal consistency of IMPACT-S was satisfying for all 9 domains (0. 75-0. 89) and excellent for the total score (0. 96). Test-retest reliability was good at item level (0. 44-0. 72), domain level (0. 72-0. 92) and total score (0. 94). Strong correlations (0. 61-0. 88) between IMPACT-S and corresponding WHODAS-II scores were found.
Conclusion: IMPACT-S is a reliable and valid generic measure of activity limitations and participation restrictions that fits the ICF.