Purpose: Contacting childhood cancer survivors (CCS) to assess reasons for declining receipt of follow-up care after treatment is difficult and participation in surveys may be low, resulting in biased results. We sought to demonstrate effective recruitment and population-based sampling methods to improve response and minimize bias.
Methods: Four hundred and seventy CCS diagnosed between 2000 and 2007 at two hospitals in Los Angeles County were selected from the California Cancer Registry and were 15-25 years of age at the time of interview. Surveys of survivors and their parents were completed by multiple methods including mail, online, and telephone. Effectiveness of "plain" versus "designer" formatting of study materials was tested. Variables associated with response were analyzed using univariate and multivariable methods. Effort required for recruitment was quantified.
Results: Fifty percent of survivors (n = 235) and 36.5% of parents (n = 171) responded, and there were 160 parent-child dyads among them. Among located survivors, 61% participated. Response was higher for women, parents of younger survivors, and those from higher socioeconomic status areas. Among Hispanics, no variables were related to response. More effort was required to reach men and older survivors, but efforts beyond 15 calls and 7 remailings were unproductive. Formatting (i.e., plain vs. designer) did not affect response.
Conclusion: Efforts to reach survivors must include multiple methods to be successful. Use of an intensive recruitment strategy and population-based sample resulted in a largely representative sample of CCS, especially for Hispanics. Expensive design efforts had little effect on recruitment, suggesting that plainer materials are sufficient. This example may inform similar studies.
Keywords: cancer registry; parents; population-based sample; response bias; response rate; survey methods.