A comparison of results from an alcohol survey of a pre-recruited internet panel and the National Epidemiological Survey on Alcohol and Related Conditions Youth Alcohol Prevention Center, Boston University School of Public Health Timothy Heeren Erika M. Edwards David L. Rosenbloom Ralph W. Hingson © 2007 Knowledge Networks, Inc. Prepared for: Knowledge Networks J. Michael Dennis Sergei Rodkin Youth Alcohol Prevention Center, Boston University School of Public Health

1 Objectives Examine the representativeness of responses to an internet- based, alcohol-related survey Compare the survey responses from those provided by the internet panelists and the NESARC respondents

2 Boston University Annual Alcohol Survey Knowledge Networks (KN) conducted 3,740 interviews with KnowledgePanel SM members 18–39 year olds At least 12 drinks in the last 12 months or any other 12 month period All KnowledgePanel SM cases were screened online 3,410 completed online 330 completed by phone (selected at random)

3 Non-Response Follow-up Target respondents who Refused to join KnowledgePanel SM Joined but later withdrew from KnowledgePanel SM Screening and interviews done by telephone 615 completed interviews

4 Boston University Annual Alcohol Survey Summary Non-Response Follow-Up Sample (NRFUS) by Telephone Panel Sample by Telephone Panel Sample by Internet Panel Acceptors Panel Rejecters RDD Sample

5 Instrument Key Topics Covered: Quantity and frequency of alcohol consumption Age of drinking onset Alcohol dependence Demographic questions Administration length (mean): 40 minutes Survey available in English or Spanish Note: Some questions were taken from NESARC survey for comparison

6 Face-to-Face Survey: Benchmark Data National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) Conducted by the U.S. Census Bureau for National Institutes on Alcohol Abuse and Alcoholism (NIAAA) in 2001–2002 Face-to-face interviews with 43,093 adults ages 18 and older Multi-stage probability sample, response rate – 81% 11,549 respondents age 18 to 39 who had 12 drinks in 12 month period were selected for analyses

7 Results – Demographics 1 (Ever Drinkers) NESARC In-Person n=(11,549) (weighted) KN Internet Panel (n=3,406) (unweighted) KN NRFUS by Telephone (n=603) (unweighted) Age 18 – – – 39 Gender Male Female * * 65.5* * Differences in percentages vs. NESARC corresponding to an odds ratio of 1.5 or greater

8 Results – Demographics 2 (Ever Drinkers) NESARC In-Person n=(11,549) (weighted) KN Internet Panel (n=3,406) (unweighted) KN NRFUS by Telephone (n=603) (unweighted) Education Less than high school High school Some college Bachelors or higher Race/Ethnicity White, non-Hispanic Black, non-Hispanic Hispanic Other * * Differences in percentages vs. NESARC corresponding to an odds ratio of 1.5 or greater

9 Results – Alcohol-Related Characteristics No significant differences were found between NESARC and KnowledgePanel SM for the following characteristics: Ratio of Current to Former Drinkers Age of Drinking Onset Frequency of Drinking Usual Quantity Family History with Alcohol (Positive vs. Negative)

10 Results – Odds of Lifetime Diagnosis of Alcohol Dependence on Age of Drinking Onset and Other Risk Factors (Ever Drinkers) NESARC In-Person (n=11,549) KN Internet Panel supplemented with NRFUS telephone (n=4,021) Age of drinking onset < NIAAA drinking guidelines Low risk Moderate risk High risk Family history of alcoholism Yes No 4.2 (3.1, 5.7) 2.8 (2.1, 3.7) 2.5 (2.0, 3.1) 1.7 (1.3, 2.1) Ref. 5.0 (3.9, 6.3) 21.2 (16.9, 26.6) 1.8 (1.6, 2.1) Ref. 3.0 (1.8, 5.1) 3.0 (2.0, 4.5) 1.9 (1.3, 2.6) 1.4 (1.0, 2.0) Ref. 5.1 (3.1, 8.5) 21.4 (12.9, 35.7) 1.7 (1.3, 2.1) Ref. Controlling for age, sex, race, education. No significant differences between NESARC and Internet Panel.

11 Results – Alcohol-Related Characteristics Among Current Drinkers NESARC In-Person (n= 9,893 ) KN Internet Panel supplemented with NRFUS telephone (n= 3,340 ) Maximum number of drinks 1–3 4–5 6–9 10+ NIAAA drinking guidelines Low risk Moderate risk High risk * 56.2* 16.2 * Differences in percentages vs. NESARC corresponding to an odds ratio of 1.5 or greater

12 Results – Alcohol Related Characteristics Heaviest Drinking Period, Ever Drinkers NESARC In-Person (n=11,549) KN Internet Panel supplemented with NRFUS telephone (n=4,021) Maximum number of drinks 1–3 4–5 6–9 10+ NIAAA drinking guidelines Low risk Moderate risk High risk Alcohol dependence Never dependent Ever dependent * * 17.6* * 63.9* 36.1* * Differences in percentages vs. NESARC corresponding to an odds ratio of 1.5 or greater

13 Conclusions from the Boston University Principal Investigators Internet panel estimates of drinking characteristics reflect those of the national population of drinkers Internet panel under represents younger and lower educated drinkers Internet panel reported somewhat higher levels of drinking behavior for heaviest drinking period No significant associations found in multivariate tests between sample type (KN panel and KN off-panel telephone surveys) and risk factors for alcohol dependence (family history, risky drinking category, and age of onset)

Contact Information Timothy Heeren Sergei Rodkin