Accuracy of racial classification of Vietnamese patients in a population-based cancer registry.
Racial classification of Asian subgroups is increasingly important for health statistics, given the growing Asian-American populations. This study reports the reliability of racial classification of Vietnamese in population-based cancer registry data from northern California. From the Greater Bay Area Cancer Registry, we selected 2240 persons diagnosed with cancer in 1989-1992 and whom the registry considered Vietnamese by birthplace and/or registry race and/or surname, or who were Southeast Asian or Chinese by race. One thousand ninety persons (49%) were interviewed. Sensitivity and predictive value positive, and cancer incidence rates, were calculated using different combinations of the classification factors (birthplace, registry race, and name). By registry-reported race alone, 74% of those the registry classified as Vietnamese agreed with this classification on interview, while 90% of those identifying themselves as Vietnamese were so classified. With classification based on 2 of 3 factors, 78% of those classified as Vietnamese agreed, and 91% of self-reported Vietnamese were correctly classified. Misclassification was associated with age, sex, year of immigration, education, and language use. Registry-based annual age-adjusted all-site cancer incidence rates per 100,000 for Vietnamese were 287.7 for males and 221.3 for females. Rates adjusted for self-reported ethnicity were 242.8 (male) and 213.7 (female). Registry classification of Vietnamese is currently problematic. Approximately 20% of cancer cases classified as Vietnamese are probably not Vietnamese. The higher incidence rates for Vietnamese in the United States than in Vietnam partly may reflect such classification error.
Northern California Cancer Center, Union City, USA.
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Swallen
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Glaser
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Stewart
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West
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Jenkins
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McPhee
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001210:Asia, Southeastern / Q000208:ethnology; D044466:Asian People / Q000145:classification*; D002140:California / Q000453:epidemiology; D002681:China / Q000208:ethnology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D012042:Registries; D014744:Vietnam / Q000208:ethnology