The intended sample size in the qualitative stream is 60 participants, of whom approximately 30 will be randomised to each study arm.
Both streams will follow the same procedure including all quantitative measures completed via telephone, but women in the qualitative stream will be invited for additional interviews at the time points specified.
Therefore to achieve our 2-week follow-up target sample of 814 women in the quantitative stream and 60 in the qualitative stream (see below) we aim to recruit approximately 1078 women into the study.
Participants in the qualitative stream undergo additional in-depth interviews at each time point to explore the views and experiences of women who do and do not choose to have screening.
Quantitative, mixed-method and qualitative streamed and extracted data were summarized in Tables 4 and 5. JN checked data extraction and any queries were resolved by consensus with EV.
Based on current participation in BreastScreen we expect between 25% and 50% of the women will choose not to be screened, giving us a meaningful sample of women choosing to screen and not to screen within the qualitative stream.
During the second telephone contact, participants will be randomised to either stream A or receive invitation to the qualitative stream B (described by the telephone interviewer as an 'enhanced version' of the study) to achieve the desired sample size in each stream (ie, in an allocation ratio of approximately 13:13.
The study uses a randomised trial design with conventional quantitative outcomes plus an embedded longitudinal qualitative substudy (streams A (quantitative) and B (qualitative)—see figure 1).
Studying communication about a trial in the light of two qualitative data streams has enabled us to consider how communication might assist optimal accrual.
The analysis of ethical guidelines was designed to address objective a, the synthesis of other quantitative and qualitative studies (streams 2 and 3) was designed to explore objectives b and c.
