Intrarater reliability of the Abilitator-a self-report questionnaire on work ability and functioning aimed at the population in a weak labour market position: a test-retest study.

Abstract

The Abilitator is a patient-reported outcome measure (PROM) of work ability and functioning of those in a weak labour market position. It covers items for work ability and self-rated health, for example, and summary scales for social, psychological, cognitive and physical functioning, as well as everyday skills. The aim of this study was to evaluate the intrarater test-retest reliability, internal consistency and basic psychometric properties of the Finnish version of the Abilitator. The test-retest study was conducted in European Social Fund projects in 2018-2019. The participants completed two Abilitator questionnaires over 7-14 days. The internal consistency analysis was based on data collected in 2017-2019 in services for the long-term unemployed. The reliability was assessed using correlations (<i>r, r_s</i> , intraclass correlation coefficient (ICC)), agreement with Bland-Altman analysis and internal consistency with Cronbach's alpha. The test-retest study had 67 participants (52% men, mean age 43.9 years) and the internal consistency study 10 923 (48% men, mean age 38.58 years), respectively. Of all the participants, 80% had been unemployed for over a year. The test-retest <i>r</i> or <i>r_s</i> ranged from 0.71 to 0.93 and ICC from 0.74 to 0.93 for the items and summary scales. An exception was the life satisfaction item, with an <i>r_s</i> of 0.60 and ICC of 0.45. A statistically significant difference was observed in the summary scale for social functioning (t=-2.01, p=0.049). Agreement was observed for all variables except social functioning. Alphas for summary scales ranged from 0.74 to 0.91. The Finnish version of the Abilitator is a reliable PROM for the target group and has acceptable to excellent intrarater test-retest reliability and internal consistency, apart from the life satisfaction item. Further testing is needed for the social functioning summary scale.