As a cardiologist with a particular interest in medical liability, I was intrigued by the recent study on misdiagnosed cardiovascular disease by general practitioners in The Joint Commission Journal on Quality and Patient Safety. This study—by The Doctors Company and CRICO Strategies—found that a significant proportion of liability cases involving cardiovascular disease were due to errors of diagnosis. This is unsurprising, and consistent with previous research. The initial presentation of cardiovascular disease can be quite ambiguous. Persistent chest pain may be due to cardiac ischemia, but there are numerous benign, or non-cardiac, explanations as well. These include gastrointestinal disorders such as reflux disease or esophageal spasm, musculoskeletal diseases such as chest wall inflammation, or vascular disorders such as pulmonary embolism or aortic dissection.
There are many tests that can clarify the clinical picture, but universal diagnostic testing is clearly not an option. One common way the list of potential diagnoses is culled to a more manageable level is by using the principle of pretest probability. The concept is very intuitive: The likelihood that a patient’s complaints are due to cardiac disease is strongly influenced by whether a patient has a high pretest risk of cardiovascular disease, including risk factors such as diabetes or hypertension. For example, it is very unlikely that a young woman with no cardiac risk factors would develop acute coronary syndrome. If a patient like this presents with chest pain, she should not undergo an aggressive workup to rule out that diagnosis, since that workup would almost certainly be negative.
Despite these relatively straightforward algorithms, defensive medicine persists. As this study mentions, patients who are unlikely to have cardiac pathology continue to receive excessive workups. There are many likely explanations for this, one of which may a continuing fear of misdiagnosing a rare or otherwise ambiguous case, despite the low pretest probability. Nobody wants to face a lawsuit because they failed to order a test, even if the patient had no risk factors. It is possible that non-cardiologists may be even more risk averse, as they do not specialize in the evaluation of cardiovascular disease.
However, the most interesting aspect of this recent study is that it suggests that perhaps the real liability danger doesn’t come from unusual or ambiguous cases, but from the relatively straightforward ones. In this study, in many of the liability cases when a cardiac illness was missed, the patient had at least one cardiac risk factor. These patients were not low risk, but at least intermediate to high risk. In such cases, cardiovascular disease needs to be considered. Sometimes even relatively easy cases can be a source of liability risk.
The take-home message is that perhaps practitioners shouldn’t worry as much about getting burned by unusual or unexpected cases. Risk-stratify your patients based on their previous medical history, and focus on the fundamentals.