Presenting the improved possibility for staying well might be better than talking about change in risk: Use of the Non-Occurrence Probability Increase (NOPI)

OBJECTIVE: Talking about risk with patients is problematic since the individual's risk is not addressed and is usually very low. This study aimed to see how fact presentation influenced the decision-making process for general practitioners concerning treatment for the prevention of cardiovascular disease. Rather than looking at the risk of becoming ill, often presented as high figures of relative risk reduction (RRR), it could be useful to present the probability of staying well, i.e. from the concept of non-occurrence probability (NOP) and non-occurrence probability increase (NOPI) – simply a single measure of change in NOP. DESIGN: General practitioners (GPs) had personal response keypads to answer two questions, presented differently, concerning whether they would allow themselves to be treated or not be treated for the risk of cardiovascular death. SETTING AND SUBJECTS: Five audiences consisting of general practitioners attending lectures. RESULTS: When the question was presented as RRR, 68% and 86%, respectively, of the physicians responded that they would take the decision to treat. When presented as the concept of NOPI the figures were reduced to 18% and 16%, respectively (p < 10–6). IMPLICATIONS: Developing tools to explain treatment effect is crucial to enhancing health care quality. Since NOPI is one potential way of presenting prevention of risk we encourage future research to evaluate the NOPI concept compared with RRR and absolute risk reduction (ARR).