The influence of question wording on assessments of interest in genetic testing for breast cancer risk.

The purpose of this study was to compare the results of different measures of interest in genetic testing for breast cancer risk. A telephone survey of a random sample of women without breast cancer was conducted in British Columbia, Canada. Interest in genetic testing for breast cancer risk was measured in three ways: (1) an unprompted assessment of interest, (2) assessment of interest when prompted with a hypothetical offer of testing, and (3) assessment of interest when provided with supplementary information. Substantial differences in reported levels of interest in genetic testing were observed across the different assessment approaches, with the unprompted assessment of interest resulting in lowest levels of interest. The highest levels of interest were observed when the assessment of interest was prompted with a hypothetical offer of testing. Factors predicting interest in genetic testing varied depending on the assessment measure used. These findings suggest that more attention must be given to measurement issues, including complete reporting of measures used in research, development of standardized approaches to assessing interest in genetic testing, and more rigorous psychometric evaluations of measures of interest in genetic testing.