Department of Nutritional Sciences, University of Toronto, Canada; Department of Pediatrics, St. Michael's Hospital, Toronto, Canada; Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada. Electronic address: omandj@smh.ca.
Measuring ethnicity accurately is important for identifying ethnicity variations in disease risk. We evaluated the degree of agreement and accuracy of maternal ethnicity measured using the new standardized closed-ended geographically based ethnicity question and geographic reclassification of open-ended ethnicity questions from the Canadian census.
A prospectively designed study of respondent agreement of mothers of healthy children aged 1-5 years recruited through the TARGet Kids! practice-based research network. For the primary analysis, the degree of agreement between geographic reclassification of the Canadian census maternal ethnicity variables and the new geographically based closed-ended maternal ethnicity variable completed by the same respondent was evaluated using a kappa analysis.
Eight hundred sixty-two mothers who completed both measures of ethnicity were included in the analysis. The kappa agreement statistic for the two definitions of maternal ethnicity was 0.87 (95% confidence interval, 0.84-0.90) indicating good agreement. Overall accuracy of the measurement was 93%. Sensitivity and specificity ranged from 83% to 100% and 96% to 100%, respectively.
The new standardized closed-ended geographically based ethnicity question represents a practical alternative to widely used open-ended ethnicity questions. It may reduce risk of misinterpretation of ethnicity by respondents, simplify analysis, and improve the accuracy of ethnicity measurement.