On 2015 Sep 17, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

The HBRC Journal Club reviewed this paper, which investigates the effects of a decision aid administered in primary care on men’s intention to undergo prostate cancer screening. The authors conducted a randomised trial in a large number of general practices in France, in a mix of rural and urban areas. The topic intersects with several challenging and controversial areas of public health policy.

The authors report that the intervention (consisting of a double-sided sheet of A4 describing various aspects of PSA testing) reduced the proportion of recruited men who intended to be screened for prostate cancer. However, although the study is stated to be a pragmatic trial, it is unclear how the intervention and associated findings apply to standard practice. Specifically, men appear to have been provided with the decision aid despite having given no indication that they were interested in PSA screening or concerned about prostate cancer, whereas these are the scenarios in which a decision aid is more likely to be used (notwithstanding possible differences between general practice in the UK and France). It is likely that men who spontaneously raise the issue of PSA screening with their general practitioner have preconceptions about the harms and benefits that are different to men who are not yet aware of it, which would lead them to respond to the decision aid quite differently. Moreover, the control condition, in which participants received only a questionnaire about prostate screening, may have had the paradoxical effect of increasing intentions among men who had not previously been considering prostate screening by raising the option without giving any indication of the associated harms.

We also discussed characteristics of the decision aid itself. Inevitably, designing information for lay people involves a balance between competing priorities: it needs to be concise enough to be manageable within a given context (general practice, in this case) but comprehensive enough to convey all the desired detail. It also needs to be comprehensible to the target audience, most of whom will not be familiar with medical terminology or statistics. These competing trade-offs are made clear in this study, in which it appears that brevity has been prioritised over completeness. For example, we noted that there is no explicit information about the (limited) benefits of PSA screening on the first page of the decision aid, nor is there an estimate of the risk of false positives and overdiagnoses within the icon array. One might take the principled view that it is important to provide this information in order for men to be able to make an informed choice. Alternatively, one might take a pragmatic view that such information would burden participants with unnecessary detail. However, what constitutes the optimal method is subject to debate and is often a matter of personal opinion.

A strength of the design was the follow-up question on the reasons underpinning participants’ screening intentions since this highlighted some of the specific viewpoints that were altered by the intervention. However, the study was limited by omitting a measure of knowledge, which is a necessary component of informed decision-making. For example, the study could have assessed whether the intervention was successful in terms of making participants aware of the possibility of overdiagnosis and lack of evidence to support a reduction in all-cause mortality.

The HBRC Journal Club found this to be an interesting study, which benefited from its large sample size, randomised design and ‘intention reasons’ as a secondary outcome measure. However, it was limited by unclear applicability to standard practice and lack of additional secondary outcomes. In particular, this study illustrates the challenges of generating universally accepted information about screening.

Conflicts of interest. We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.

On 2015 Sep 17, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

The HBRC Journal Club reviewed this paper, which investigates the effects of a decision aid administered in primary care on men’s intention to undergo prostate cancer screening. The authors conducted a randomised trial in a large number of general practices in France, in a mix of rural and urban areas. The topic intersects with several challenging and controversial areas of public health policy.

The authors report that the intervention (consisting of a double-sided sheet of A4 describing various aspects of PSA testing) reduced the proportion of recruited men who intended to be screened for prostate cancer. However, although the study is stated to be a pragmatic trial, it is unclear how the intervention and associated findings apply to standard practice. Specifically, men appear to have been provided with the decision aid despite having given no indication that they were interested in PSA screening or concerned about prostate cancer, whereas these are the scenarios in which a decision aid is more likely to be used (notwithstanding possible differences between general practice in the UK and France). It is likely that men who spontaneously raise the issue of PSA screening with their general practitioner have preconceptions about the harms and benefits that are different to men who are not yet aware of it, which would lead them to respond to the decision aid quite differently. Moreover, the control condition, in which participants received only a questionnaire about prostate screening, may have had the paradoxical effect of increasing intentions among men who had not previously been considering prostate screening by raising the option without giving any indication of the associated harms.

We also discussed characteristics of the decision aid itself. Inevitably, designing information for lay people involves a balance between competing priorities: it needs to be concise enough to be manageable within a given context (general practice, in this case) but comprehensive enough to convey all the desired detail. It also needs to be comprehensible to the target audience, most of whom will not be familiar with medical terminology or statistics. These competing trade-offs are made clear in this study, in which it appears that brevity has been prioritised over completeness. For example, we noted that there is no explicit information about the (limited) benefits of PSA screening on the first page of the decision aid, nor is there an estimate of the risk of false positives and overdiagnoses within the icon array. One might take the principled view that it is important to provide this information in order for men to be able to make an informed choice. Alternatively, one might take a pragmatic view that such information would burden participants with unnecessary detail. However, what constitutes the optimal method is subject to debate and is often a matter of personal opinion.

A strength of the design was the follow-up question on the reasons underpinning participants’ screening intentions since this highlighted some of the specific viewpoints that were altered by the intervention. However, the study was limited by omitting a measure of knowledge, which is a necessary component of informed decision-making. For example, the study could have assessed whether the intervention was successful in terms of making participants aware of the possibility of overdiagnosis and lack of evidence to support a reduction in all-cause mortality.

The HBRC Journal Club found this to be an interesting study, which benefited from its large sample size, randomised design and ‘intention reasons’ as a secondary outcome measure. However, it was limited by unclear applicability to standard practice and lack of additional secondary outcomes. In particular, this study illustrates the challenges of generating universally accepted information about screening.

Conflicts of interest. We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.