Abstract
Objective: To describe the enrollment rates and individual characteristics of Hispanics and non-Hispanics invited to participate in a multi-site Web-based intervention promoting increased fruit and vegetable consumption (MENU).
Methods: A total of 5751 randomly selected members were invited to enroll in a Web-based nutritional study. Probable Hispanic status was determined by the Latino surname algorithm based on the Passel-Word Spanish Surname List utilized by the 1990 US Census. We computed enrollment rates stratified by ethnicity status and used logistic regression to examine characteristics associated with the likelihood of enrollment. To address potential bias associated with the use of Hispanic surname, sensitivity analyses were conducted comparing self-reported ethnicity of enrolled members to the Passel-Word-identified ethnicity.
Results: There were 2871 probable Hispanics and 2880 probable non-Hispanics invited to join the study. A total of 174 (6.1%) probable Hispanics and 340 non-Hispanics (11.8%) enrolled in the study for a total enrollment of 514 (8.9%) invitees. Overall, Hispanics were 47% less likely to enroll, females were four times as likely to enroll, and those people with a median income census tract less than $41,994 were 44% less likely to enroll. Stratifying by probable ethnicity status suggests Hispanics females were 87% more likely to enroll and Hispanics with a median income census tract less than $41,994 were 46% less likely to enroll while the odds for non-Hispanics enrolling increased 14% for each decade increase of age and non-Hispanics with a census tract median income less than $41,994 were 43% less likely to enroll in MENU. Self-reported Hispanic rates showed a sensitivity of 91.1% and specificity of 88.8%. Total enrollment of Hispanics into MENU totaled 192 (7.6%), of which 146 (76.0%) were enrolled by Kaiser Permanente Colorado.
Conclusions: This study demonstrates that identifying Hispanics through surname for oversampling can be highly successful in terms of sampling yield and accuracy. However, results from this study suggest that Hispanics are significantly less likely to enroll in a Web-based nutritional intervention. Additional research is needed to identify methods of attracting more Hispanic subjects to these kinds of interventions.
- Received September 11, 2008.
