The California Health Interview Survey (CHIS) is the nation’s largest statewide
ID: 3242709 • Letter: T
Question
The California Health Interview Survey (CHIS) is the nation’s largest statewide telephone health survey. The CHIS has been conducted biennially since 2001 using a two-stage process that is designed to generate a sample that represents the state. At the first stage, telephone numbers are drawn within predefined geographic areas. Telephones numbers are screened to determine if they are contained in households and are thus eligible for the survey. At the second stage, one adult is randomly selected among all adults living in a household. The adult response rates for CHIS 2003 and 2005 were 33.5% and 26.9%, respectively. Does the low response rate imply survey bias?
A) Not necessarily—it would depend on your study and what group was left out.
B) Yes, low response rates always imply survey bias.
C) No, response rate is not associated with survey bias.
Explanation / Answer
Answer (B) Yes, low response rates always imply survey bias.
Reason Non-response bias is the error resulting from distinct differences between the people who responded to the survey versus the people who did not respond. Response rate can be used as one way to gauge the potential for non-response bias. The lower the response rate of a survey, the higher the risk of non-response bias or survey bias.