Content validity and reliability of a university food environment assessment instrument

Abstract

This study aimed to evaluate the content validity and reliability of an instrument for evaluating the university food environment. A checklist was developed to assess establishments that sell food and beverages in the university en-vironment. The content validation encompassed the development of the instrument, expert evaluation and pretest performance. Reliability was evaluated using a convenience sample (n=64) of establishments distributed across seven campus-es of three public universities and was carried out using interobserver (IO) and test-retest (TR) evaluations. Categorical and count variables were analyzed by calculating the percentage agreement (PA), kappa coefficient (k) and prevalence-ad-justed, bias-adjusted kappa (ka), and continuous variables were analyzed by the intraclass correla-tion coefficient (ICC). The checklist consisted of 204 items distributed in seven domains. The in-strument’s performance was considered excellent or very good for 91.3% (PA) of the items when evaluated. For IO, 68.3% (k) and 96.5% (ka) had excellent, very good or good agreement, while for TR, 65% (k) and 96.5% (ka) had excellent agree-ment. The instrument showed satisfactory content validity and reliability for characterizing the food environment at Brazilian universities.