We sought to examine physicians' self-reported awareness, use in clinical practice, and attitudes regarding CHD global risk assessment for primary prevention and how this varies by provider type. Our study found that among a sample of US physicians: (1) awareness of tools to calculate CHD global risk is extremely high, (2) use of CHD global risk calculation in practice is low, (3) the most strongly endorsed reason for not calculating a patient's global CHD risk appears to be that it is too time consuming, (4) overall use of global CHD risk calculation to guide primary preventive pharmacologic therapy is low and infrequently used to guide aspirin recommendations.
Our finding that use of CHD global risk calculation by US physicians is low is concerning since national guidelines for primary prevention of CHD are based on individuals' calculated 10-year CHD risk levels. For example, use of global CHD risk is advocated by national cholesterol treatment guidelines to better identify people who will benefit from intensive treatment . Additionally, the decision to use aspirin for primary prevention is one that needs to be weighed against the potential for harm from gastrointestinal bleeding or hemorrhagic stroke . Due in part to the potential harms associated with preventive pharmacotherapy, calculating a patient's global CHD risk is an important step, allowing adjustment of the intensity of intervention to the overall risk:benefit ratio for the patient [3, 13, 17, 18]. Still, in our sample, the majority of physicians who were aware of CHD risk assessment tools reported they did not use CHD risk assessment to guide primary preventive pharmacotherapy decisions. Evidence suggests that when 10-year coronary risk information is given to physicians, prescription of guideline concordant lipid-lowering and aspirin therapies is slightly improved .
The most commonly endorsed barrier to CHD risk assessment use is the perception that it is too time consuming. It has been shown previously that one of the main barriers to delivery of preventive health services in primary care is lack of time . However, a recent study found that even with limited time, primary care physicians address many of the highest rated preventive services, including cholesterol and BP management, adequately . While lack of time during primary care patient visits is certainly a valid concern, there are many tools available that offer quick and accurate calculation of a patient's CHD risk . Physicians in our sample who use a PDA or similar device when seeing patients in the clinic were more likely to use CHD risk assessments than those who do not. This suggests that CHD risk calculator programs for PDAs or smartphones may be a method of increasing CHD risk assessments among physicians. Fortunately, several CHD risk calculation tools are already available for such devices . Other CHD risk assessment tools include paper risk charts, spreadsheet programs for computers and web-based calculators . Additionally, some EMR's extract risk factor data from patients' records and calculate and display 10-year CHD risk for clinical use. Uncertainty remains regarding which tool for calculating CHD risk produces the most favorable patient outcomes. One study showed that use of a computer based clinical support system added to a paper risk chart was not as effective as a paper chart alone in terms of systolic BP control over one year . However, the computer based system required manual input of patient risk factors, as opposed to an automatic risk calculation embedded in an EMR .
Other barriers are that some physicians report that they do not find the assessment of global CHD risk useful in practice and are unsure how to use the risk calculation in practice. Cardiologists were most likely to indicate that CHD risk assessment is not useful in clinical practice, which could potentially be related to the lower proportion of patients seen for which primary prevention (rather than secondary prevention) is of concern. General internists and family physicians were more likely to indicate that they are not familiar enough with how to use CHD risk calculations, and that there are no accurate or easy tools available to calculate CHD risk. These responses suggest a need to develop educational interventions for physicians that discuss the use of global CHD risk calculations in clinical practice [2, 3, 22].
In addition to its usefulness in helping clinicians and patients make decisions about preventive pharmacotherapy that take into account the balance of benefits and harms, global CHD risk could also be used to motivate patients [15, 16]. However, we found that only 40% of those who use CHD risk assessments inform patients of their global CHD risk estimate. In total, while a majority of physicians who use CHD risk assessments use them either to guide prescription decisions or to motivate patients, an appreciable number do not. This suggests that even when CHD risk is calculated by physicians in practice, they may be unaware of how to utilize this risk information to its full advantages.
Our findings illustrate the need for interventions to increase uptake and effective use of global CHD risk assessment for guiding primary prevention. Development of effective interventions to improve guideline adherence by physicians should consider the variety of barriers to implementation in order to be successful . While the type of intervention that is most effective remains unknown, education in small doses as well as passive guideline dissemination have been shown to be ineffective methods for affecting physician behavior change . Paper and electronic reminders may be the most effective single intervention; however, it is likely that multiple tools will be necessary to increase guideline adherence among physicians . The use of guideline concordant decision aids, programs embedded in EMRs that automatically calculate and display risk values and action thresholds, and risk charts in patient exam rooms are examples of system improvements that warrant further investigation.