Research shows that patients and doctors tend to overestimate the benefits of treatment, while underestimating harmful effects. The optimism of patients and doctors alike is often boosted by the systematic optimism of the medical literature (Br J Psych 2010;197:441-7). However, in the case of percutaneous coronary intervention this can not be used as an excuse. Experts and guidelines could not be clearer – with the exception of immediate intervention following acute myocardial infarction, percutaneous coronary intervention improves symptoms but not survival. Furthermore, it does not reduce the risk of future myocardial infarction. In short, percutaneous coronary intervention should only be offered to patients with stable coronary artery disease if medical treatment is failing to manage their angina.

Kureshi et al (see editor’s research choice, page 42) confirm that patients still believe that it will do more than just control their symptoms. Of about 1,000 patients surveyed, the vast majority thought that the procedure would extend or save their lives and would prevent myocardial infarction. Only 1% of patients correctly reported that relief of their symptoms was the only expected benefit.

In an editorial that accompanies Kureshi’s BMJ paper, Whittle et al (including patients) ask why patients may perceive or be given the impression that an intervention may have benefits that are not based on scientific evidence (BMJ 2014; 349:g5613). The three coauthor patients all have personal or family experience of coronary revascularisation. Their views may prompt new thinking. One recalled that, although there was no statement that the procedure would prolong life, he sensed that the surgeon thought it would. Another was made aware of the seriousness of his condition and was congratulated on its early discovery, which perhaps suggested that intervention would change the course of the disease. A third noted that having lots of time for questions doesn’t help if the patient doesn’t know what questions to ask.

The editorial also considers what it accepts might be a heretical question: does it matter if patients don’t have an entirely accurate understanding of the benefits of treatment? They conclude that it may not – and go as fas as to say that it may be demoralising for patients to insist on them understanding that the treatment won’t prolong their life.

Surely there can be no excuse for misleading patients, consciously or otherwise, about the risks and benefits of therapeutic interventions. Is it perhaps the case that we are deceiving ourselves, as well as patients when we present an over-optimistic assessment of the value of treatment. What of the risks of overtreatment based on unrealistic expectations? In their study, Kureshi et al found that patients’ level of understanding varied between the 10 different sites and that the informed consent procedures differed. 

Finally, there is a possibility that where an operator is being remunerated for an intervention there is a tendency towards such intervention. Even where incentives are not financial, different specialists see clinical scenarios from different perspectives. The oncologist and the palliative care physician, for example, will exhibit different priorities for the management of metastatic lung cancer. Similarly the gastroenterologist and the gastrointestinal surgeon may differ in their approach to the management of inflammatory bowel disease.

It is vital, therefore, that all treatments should be evidence-based and that discussion of the evidence should form part of the consent process.