The psychometric properties of the Chinese version-reintegration to normal living index (C-RNLI) for identifying participation restriction among community-dwelling frail older people

Background: The Reintegration to Normal Living Index (RNLI) was developed to measure reintegration to normal living after major traumas/illnesses. Its psychometric properties remain unknown when used to measure participation restriction under the World Health Organization's International Classification of Functioning, Disability, and Health (WHO-ICF) framework. This study examines the psychometric properties of the Chinese version-RNLI to measure WHO-ICF participation restriction among community-dwelling pre-frail and frail older people.

Methods: A cross-sectional study was conducted in community and day-care centres in Hong Kong between May 2015 and January 2016. Through face-to-face interviews, information was collected on the participants' demographic background, medical history, frailty status, depressive mood, functional performance in daily activities, and participation restriction. The internal consistency, test-retest reliability, and construct and convergent validity of the C-RNLI were assessed.

Results: Two hundred and ninety-nine pre-frail or frail community-dwelling older people with a mean age of 79.53 were recruited. A confirmatory factor analysis showed that the C-RNLI has a two-factor structure comprised of "participation in physical activities" and "participation in social events". The test-retest coefficient was 0.71. The Cronbach's alpha of the total C-RNLI score, and those of the factors "participation in physical activities" and "participation in social events" were 0.88, 0.82 and 0.84, respectively. Pre-frail older people had significantly higher scores for the factors "participation in physical activities" (z = -5.05, <0.01) and "participation in social events" (z = -6.04, p < 0.01) than frail older people. Older people from community centres had significantly higher scores for the factors "participation in physical activities" (z = -4.48, <0.01) and "participation in social events" (z = -4.03, p < 0.01) than older people from day-care centres. The factors "participation in physical activities" and "participation in social events" of the C-RNLI were significantly convergent with depressive mood (r_s = -0.25 and r_s = -0.39, respectively) and functional performance in daily activities (r_s = 0.28 and r_s = 0.45, respectively).

Conclusions: The C-RNLI is a two-factor structured scale with acceptable level of reliability and validity to measure WHO-ICF participation restriction among community-dwelling pre-frail and frail older people.