The Validity and Reliability of the Functional Impairment Checklist (FIC) in the Evaluation of Functional Consequences of Severe Acute Respiratory Distress Syndrome (SARS)

Severe acute respiratory distress syndrome (SARS) contributed to significant mortality and morbidity worldwide. We aimed to establish the validity, reliability and responsiveness of the functional impairment checklist (FIC) as a measurement tool for physical dysfunction in SARS survivors. One hundred and sixteeen (65 females and 51 males, mean age 45.6) patients who joined the SARS rehabilitation programme were analysed. The factor analysis yielded two latent factors. The mean FIC-symptom and FIC-disability score were 24.12 (SD ± 20.2) and 26.11 (SD ± 27.32), respectively. Based on the item-scale correlation coefficients, the Cronbach’s alpha coefficients reflecting the internal consistency reliability of scale score were 0.75 for FIC-symptom and 0.86 for FIC-disability. Test–retest reliability in 23 patients showed no statistical significant difference in the FIC scores between tests with intraclass correlation coefficient (ICC) 0.49–0.57. The FIC scales correlated both with 6 munute walking test (6MWT) distance (−0.26 and −0.38) and handgrip strength (HGS) (−0.20 and −0.27). Moreover, the FIC scales correlated with St. George’s respiratory questionnaire (SGRQ) (0.19 to 0.52) and short form 36 Hong Kong (SF-36) domains (−0.19 to −0.59). Both FIC scales correlated stronger with physical component summary (PCS) (−0.41 and −0.55) than with mental component summary (MCS) (−0.30 and −0.23). FIC reduced significantly at 6 months while the SF-36 PCS and MCS did not show any change. In conclusion, the study results indicate the FIC is reliable, valid and responsive to change in symptom and disability as a consequence of SARS, suggesting it may provide a means of assessing health related quality of life (HRQOL) outcomes in a longitudinal follow up.