Discussion
cancer, anxiety, cancer worry
CANCER
There was no evidence from this study that offering BC-Predict resulted in any effect on psychological harms, such as general anxiety or cancer worry, or benefits, such as screening knowledge, compared to offering NHSBSP. There was a clear pattern of the psychological impact of receiving different risk estimates provided by BC-Predict. There was a general acceptance of personal risk estimates, where women told they were at higher risk-rated their own risk as higher than baseline, and women told they were at lower risk that rated their own risk as lower. Similarly, there was an increase in worry about cancer in women told they were at higher risk and a decrease in worry about cancer in women told they were at lower risk. The changes were generally not large however, and there was no evidence of increases in clinical levels of anxiety in the BC-Predict group relative to the NHSBSP group. It was also notable that the strongest predictor of general anxiety and cancer worry at follow-up was baseline levels of these same variables, i.e., those women who experienced psychological distress at follow-up were the same women who experienced psychological distress at baseline, irrespective of whether they received BC-Predict or not, or any particular risk estimate.The present study has several strengths in comparison with previous research. Most notably, unlike in previous studies of the psychological impact of receiving risk-stratified screening in the PROCAS study [The main limitation of the present research was that we did not randomise women to receive either BC-Predict or standard NHSBSP, which should have resulted in comparable groups. By contrast, due to the approach taken the comparison group was not well matched on deprivation indices with the BC-Predict group. This lack of matching was partly due to a change in design from that originally planned, which we considered to be the best design that was feasible, given the pragmatic challenges that randomisation would have presented in this study [The other major limitation with the present research was the 11.2% questionnaire response rate of women invited to participate in the present questionnaire study. This rate was attributable to multiple factors, including lower uptake to NHSBSP during this period, as women were required to actively make an appointment rather than be allocated an appointment. It is notable that the uptake to NHSBSP in the present areas during the period of this study was only 60.7%, and that uptake of BC-Predict amongst women offered it was only 16.1% [A third potential limitation is that the number of women recruited was substantially lower than originally intended, at least partly due to the lower-than-anticipated response rate just mentioned. The sample size calculations indicated that The present research provides no evidence to support the idea that BC-Predict resulted in any psychological distress compared to the offer of standard NHSBSP. This finding is in accord with findings from the first PROCAS study [An unexpected finding was the increase in state anxiety in women who were told that they were at low risk. This finding was unexpected for three reasons. First, previous research has found that women who were told they were at lower risk showed a reduction in state anxiety [This study also found no support for any impact on future intentions to change screening, of either offering BC-Predict or of receiving any particular risk estimate. This finding is again in accordance with intentions to change behaviour found in the first PROCAS study [The final notable finding is the lack of effect of participating in BC-Predict on cancer screening knowledge. It has been proposed that one of the potential benefits of risk-stratified screening is an increase in understanding of screening [Taken as a whole, the key implication of this study is to provide the best available evidence that risk-stratified screening is unlikely to produce psychological harms in the women that are offered it. This finding is in line with previous research, but the present study has a number of strengths, including more appropriate timing of questionnaire distribution in relation to participation in risk-stratified screening, more appropriate control groups and inclusion of high-risk women [The present findings add further to the weight of evidence showing no major psychological impact of risk-stratified screening causes psychological harms in the NHSBSP. It is possible that risk-stratified screening in screening programmes in other countries or when delivered in other ways may cause psychological harms, and the ongoing MyPeBS study should address this possibility, as well as consider any harms or benefits for up to four years post screening [In sum, this study aimed to identify any psychological harms of risk-stratified screening brought about by BC-Predict, as this is one of the major barriers to risk-stratified screening that has been identified [