RESUMO
BACKGROUND: Although response rates for physician surveys have been decreasing, it is not clear whether this trend is associated with an increase in survey nonresponse bias. One means for assessing potential bias is to conduct a level-of-effort analysis that compares data estimates for respondents interviewed during the first recruitment contact to respondents interviewed at later recontact cycles. METHODS: We compared early and later responders within the Survey of Physician Attitudes Regarding the Care of Cancer Survivors with respect to both demographic characteristics and aggregate survey responses to items on survivor care knowledge, attitudes, and practices. RESULTS: Accumulating additional completions across each of 4 respondent contact attempts improved weighted response rates (35.0%, 46.9%, 52.3%, and 57.6%, respectively). However, the majority of estimates for analyzed variables remained relatively unchanged over additional cycles of recontact. CONCLUSIONS: We conclude that additional respondent recontact attempts, especially beyond a single recontact, had little influence on key data distributions, suggesting that these were ineffective in reducing nonresponse bias. Further, the conduct of additional recruitment recontacts was an inefficient means for increasing statistical power. For the conduct of physician surveys, a practice that may in some cases be cost-effective, while also controlling total survey error, is to establish a larger initial sample; to either eliminate nonresponse follow-up or to limit this to one recontact; and to accept a somewhat lower final overall survey response rate.