Figure 1.

Flow diagram of how sampled women were identified for tracing. *Returned mail, but not traced due to: 1) mail returned included information to categorize the woman as ineligible, e.g., deceased; 2) contact by telephone interviewer before the mail was returned to the study centre; 3) 1995–1997 screener questionnaire included information to categorize the sampled woman as ineligible, e.g., plans to move out of the eligible regions. ^†Identified as requiring tracing due to: 1) information letter returned in the mail to study centre or 2) incorrect telephone number at study contact by the telephone interviewer.