Recruiting doctors' involvement was restricted to diagnosis followed by determining the patients' interest in participating, excluding patients who were not eligible and a telephone referral to the on-call otolaryngology doctor.
In the screening arm, 38 496 women were invited to participate, excluding those older than 74, who had participation rates that were not as complete as younger women.
Of 13,681 left, 6,600 were randomly selected to participate, excluding 145 who were discarded due to data base errors, and 679 who we were unable to trace.
Of the original 5,362 study members at birth, 3,163 study participants known to be alive with an address in England, Scotland, or Wales were eligible to participate (excluding 718 who had died, 567 who were living abroad, 594 who had previously withdrawn from the study, and 320 who had been untraceable for >10 years).
To examine whether this approach influenced outcomes, we again used chi square tests to examine differences in participation rate, conditional participation rates, and willingness to participates, excluding patients without preference of participation mode.
Eleven persons who were too sick or incapable of participating were excluded.
Compared with non-participating (excluded) patients, included patients were 2.8 years younger (P=0.04), had 1.3 higher BMI (P=0.02), less often received axillary irradiation (8% v 16%; P=0.03), and more often received chemotherapy (68% v 58%; P=0.06).
The grounds as redefined by the researchers were incorporated in a questionnaire that was sent to respondents in each participating country, excluding the participants of the focus groups.
Women who did not meet the inclusion criteria or declined to participate were excluded and a total of 165 women agreed to participate, completed the study and were analyzed.
Faculty members were chosen based on their willingness to participate in the study, and no one who desired to participate was excluded.
Because no baseline records were available for the 1 participant who enrolled but then was unable to participate, we excluded this patient from all analyses.
