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Constantine, W.L., Haynes, C., Spiker, D., & Constantine, N.A. (1997). Recruitment and Retention. In R. T. Gross, D. Spiker, & C. Haynes (Eds.), Helping Low Birth Weight, Premature Babies: The Infant Health and Development Program. Stanford, CA: Stanford University Press. This chapter discusses the processes of recruiting and retaining a sample of low birth weight, premature infants for a clinical trial, as well as results of tests evaluating sampling and retention biases. A total of 4551 infants were screened, and 1302 were found eligible. Consent was obtained for 1028 infants. After randomization and the presentation of group assignment, the number of infants enrolled was 985 (75.7% of those eligible). Of these, 92.7% completed the 3-year study. Tests to evaluate recruitment bias revealed significant relationships between nonenrollment and site, maternal race, and birth weight. Tests to evaluate retention bias revealed a significant relationship between dropout and maternal education. Additionally, infant birth weight and maternal age interacted with treatment in predicting dropout. Despite this significant recruitment and retention biases, there was no evidence of problems with the sample representativesness to the population of interest or of treatment group differences on study-relevant background variables. |