Physicians' perception of guideline-recommended low-density lipoprotein target values: characteristics of misclassified patients

The present study investigated the awareness of primary care physicians for patient characteristics relevant for designation of low-density lipoprotein (LDL) target values. Physicians (n = 907) were asked to estimate guideline-recommended LDL target value for 30 of their patients with hyperlipidaemia. In total, 25 250 patients were allocated on that basis in three different groups (LDL target < 100, < 130, and < 160 mg/dL), in which by guideline criteria 68.0, 21.9, and 10.1% of patients, respectively, were allocated. We analysed (by logistic regression) whether physicians utilized risk factors and co-morbidities appropriately for assignment of correct LDL target values. Overall, physicians estimated recommended LDL target values correctly in 55.1% of male vs. 49.1% of female patients (P < 0.001). In the group with LDL targets of < 100 mg/dL, correct assignment was most often given to male patients with a history of myocardial infarction (MI; 77.1%). In comparison with this group, increasing probabilities for incorrect assignment were found in patients with documented coronary artery disease (CAD) without a history of MI [odds ratio (OR): 2.08, 95% confidence intervals (95% CI): 1.87-2.33], CAD-equivalent conditions (OR: 2.30, 95% CI: 2.08-2.55), and a 10-year risk > 20% based on calculated risk scores (OR: 2.69, 95% CI: 2.40-3.02). Next, physicians were grouped, based on the number of correct assignments they gave to their patients, in quartiles of guideline knowledge. In patients from physicians of the top performing quartile (> 90% of correct assignments), LDL levels were significantly lower than in the second, third, and fourth quartiles (LDL 134.3, 138.8, 145.5, 151.4 mg/dL, P < 0.001 between all groups). In primary care, about half of high-risk patients receive correct assignment of guideline-recommended LDL targets by their physicians. Perception of correct LDL target values varied largely depending on patients' gender and co-morbid conditions. Poor perception of risk resulted in lower rates of objective LDL target achievement.