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

OBJECTIVES: 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. DESIGN, SETTING AND OUTCOME: 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 (r, r(s) , intraclass correlation coefficient (ICC)), agreement with Bland-Altman analysis and internal consistency with Cronbach’s alpha. PARTICIPANTS: 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. RESULTS: The test–retest r or r(s) 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 r(s) 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. CONCLUSIONS: 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.