Public entrance accessibility: Psychometric approach to the development of a new assessment instrument

Background: The accessibility of public facilities for all is an issue increasingly gaining focus in policy debates, especially regarding the ageing population. Objective: This paper describes a psychometric approach to the development of a new instrument for assessing the accessibility of public entrances. Methods: Items to include were selected by means of literature review and classified according to a typology of person-environment fit that uses the International Classification of Functioning, Disability and Health (ICF) as theoretical framework. Content validity was assessed by a scientific panel approach and construct validity by using simulation techniques and correlation analysis with a related construct. Reliability was evaluated by inter-rater agreement analysis, where 15 strategically selected public entrances were assessed by five rater pairs. Results: Content validity was assessed as high (3.6 on a scale from 1 to 4) and correlation indicating convergent validity between instrument scores and a related construct was moderate (r _s = 0.60, p < 0.001). Inter-rater reliability was acceptable to good (kappa 0.42, overall agreement 81%). After an iterative process including review of validity and reliability results, the resulting assessment instrument consisted of 56 items in 7 sections. Conclusions: This study demonstrated good content validity and acceptable to good inter-rater reliability. Though initial results were promising, user involvement and further testing of construct validity is needed. The goal of the new instrument is a feasible tool for planning, evaluation and accomplishment of policies intended to make public entrances accessible for all. The extent to which the instrument succeeds remains to be tested by practical use.