A new instrument to measure patient satisfaction with mammography - Validity, reliability, and discriminatory power

OBJECTIVES. The benefit of mammography depends on repeated use. Therefore, surveying the mammographic quality as judged by the users addresses an important topic. The authors assess the practicality, validity, reliability, and discriminatory power of a new, brief, multidimensional questionnaire for measuring patient satisfaction with mammography. It-ems measuring discomfort and attitudes toward repeat adherence were included. METHODS. A self-administered questionnaire was given to women from six radiology departments in Norway Four hundred eighty-eight out of 550 women referred for screening or diagnostic mammography were included. Seventy-seven patients also completed the test/retest study, and 44 women additionally completed an Australian questionnaire. Scores for patient satisfaction on the structure, process, discomfort, and general satisfaction scales of the questionnaire were used as the main outcome measures. RESULTS. Response rate was 89%, and rate of completion was more than 95%. Strict psychometric criteria for construct validity and reliability were satisfied. Because lower levels of satisfaction were detectable with the new questionnaire but not with the Australian questionnaire and because an acceptable degree of variability in response was detected, support for discriminatory power was found. CONCLUSIONS. The discomfort dimension contributed substantially to validity and discriminatory power. Patient behavior with time may be monitored with the new questionnaire, thus representing a valuable tool for scientific and practical purposes.