Modern Psychometric Approaches

Abstract Health-related quality of life (HRQOL) is an outcome measure of growing interest in public health research and is concerning a person’s perceived health. Population health research often has the goal of administering large questionnaires to large numbers of participants, emphasizing the need for small scales. Furthermore, many existing national surveys administer standard health-related questions which, if validated properly, could be used to assess HRQOL. The aim of this study was to develop and validate a short HRQOL scale for rural adults using both classical and modern psychometric methods. This study analyzed data from 2,430 rural adults participating in the 2012 Montana Behavioral Risk Factor Surveillance System (BRFSS). Three self-reported items (physical health, mental health, & general health) and one constructed index for a total of four items were used to assess HRQOL. Results from factor analysis indicated a single factor model accounting for 53.5 % of the total variance. Factor loadings ranged from.48 to.82 with the mental health item contributing the least to the factor. The internal consistency analysis showed that the four-item scale was moderately reliable (KR20 =.70), however could improve (KR20 =.75) if the mental health item was dropped. The Rasch assessment confirmed dropping the mental health item due to an Outfit MnSq statistic greater than 1.50. A final three-item Rasch assessment indicated good model fit, item separation, and item reliability. This study provides psychometric evidence for the use of a three-item (physical health, general health, & healthy days) HRQOL scale (HRQOL3) with rural adults. The simplicity of th