A framework for the adaptation of psychological questionnaires for epidemiological use: an example of the Bortner Type A scale.

A model for the systematic adaptation of psychological questionnaires for epidemiological use is presented. Application of the model is illustrated using variants of the Bortner Type A scale in a representative age/sex stratified sample of 256 persons. Through the application of the model the Bortner scale was adapted to compare the effects of scale direction, scale format and example position. Overall the Bortner scale was shown to provide robust measurement which was little affected by response rate, age, sex or by the adaptations of the scale. An association was found of sex with response rate. Interaction effects of sex and scale direction on mean Type A scores, and of example position and scale format on both response rate and Type A score variability were also found. In identifying critical aspects of questionnaire performance, and in providing a coherent framework for their interrelationship, the model acts as a guide to the systematic assessment of questionnaire performance. The use of this model will, therefore, facilitate greater confidence in the interpretation of questionnaire data in epidemiological studies.