“…Most of the families who were lost in the recruiting period did not appear strikingly different from those who remained in the study. These lost families became part of a separate study that attempted to measure characteristics of families that fail to respond to an offer of medical care or, in the case of the control families, to participate in a health survey (White, Alpert & Kosa, 1967). Loss over the next 3 years averaged 7%4 a year and was similarly distributed in the experimental and control groups.…”