Challenging treatment thresholds

of Cardiology (ACC)/American Heart Association (AHA) regularly release cardiovascular disease (CVD) guidelines that recommend lifestyle and medication interventions along with treatment thresholds based either on risk factors or calculated CVD risks. The release of these recommendations predictably leads to intense debate from healthcare organisations, government, industry, and clinicians on whether or not the recommendations are reasonable. At one extreme the recommendations are typically pilloried as being sufficiently weak to cost lives, while others insist the guidelines have threatened public health through over-medication. This overwrought debate is rooted, we believe, in the mysterious imperative to provide treatment thresholds, rather than offer a reasonable synopsis of best evidence and its limitations so that patients and clinicians can apply individual values. Such a bestevidence approach would support the increasing call – and need – for shared decision making in professional society guidelines.1 Moreover, care guided by treatment thresholds largely removes individual preference from the exam room while care explicitly informed by best evidence allows tailoring to a patient’s values and priorities. When it comes to CVD risk factors, some population health advocates justify threshold-based guidelines by estimating how many heart attacks or strokes might be prevented across a population. This approach may be reasonable with vaccination for transmissible diseases, or public health regulations that demonstrate reliable and rapid real world reductions in morbidity and mortality (eg public smoking bans). However, risk factor modification with lifestyle interventions may for some individuals be unacceptably inconvenient, burdensome, or costly. In addition it is neither feasible nor desirable to speculate on a population’s values or preferences. Such questions are best left to individuals, as evidenced by one recent survey study demonstrating marked variation in negative values assigned to the act of taking daily pills: some respondents would refuse daily medications even if an inexpensive pill would cause no side-effects and add 10 years to their life.2 What current guidelines therefore fail to address is the negative value assignments associated with commonly prescribed and recommended healthcare interventions. Hopefully most clinicians and patients will agree with the principle that information is power. While not all patients will want to take the pills, undergo invasive procedures, or take on lifestyle changes commonly used for risk factor modification, all should have access to basic facts and evidence about the utility of these options.