Evaluating the equivalence of health care ratings by whites and Hispanics

PURPOSE. This study was designed to assess the equivalence of a health care ratings scale administered to non-Hispanic white and Hispanic survey respo ndents. METHODS. We sent 18,840 questionnaires to a random sample of patients recei ving medical care from a physician group association concentrated in the we stern United States; 7,093 were returned (59% adjusted response rate). Appr oximately 90% of survey respondents self-identified as white/Caucasian (n = 5,508) or Hispanic/Latino (n = 713). Interpersonal and technical aspects o f medical care were assessed with 9 items, all administered with a 7-point response format: the best, excellent, very good, good, fair, poor, and very poor, with a "not applicable" option. Item response theory procedures were used to test for differential item functioning between white and Hispanic respondents. RESULTS. Hispanics were found to be significantly more dissatisfied with ca re than whites (effect size = 0.27; P <0.05). Of the 9 test items, 2 had st atistically significant differential item functioning (P <0.05): reassuranc e and support offered by your doctors and staff and quality of examinations received. However, summative scale scores and test characteristic curves f or whites and Hispanics were similar whether or not these items were includ ed in the scale. CONCLUSIONS. Despite some differences in item functioning, valid satisfacti on-with-care comparisons between whites and Hispanics are possible. Thus, d isparities in satisfaction ratings between whites and Hispanics should not be ascribed to measurement bias but should be viewed as arising from actual differences in experiences with care.