Results
A total of 177 physicians (102 PCPs and 75 specialists) enrolled 2009 patients; Ontario contributed more than any other province with the top 4 being Ontario, BC, Quebec, and Alberta. The number of patients enrolled by specialists and PCPs was equal.
Patients enrolled by specialists were slightly older, more frequently female and Caucasian (77% vs. 65%, p=0.0001) and with other differences in clinical characteristics summarized in Table 1. Specialists had less patients on statin therapy and bile acid sequestrants but more patients on aspirin and other antiplatelet therapies as well as beta blockers (Table 1). Patients treated by specialists had slightly lower total cholesterol and triglycerides but no difference in LDL-C or non-HDL-C levels (Table 1).
At baseline and during the follow up, the specialists tended to use less statins (Figure 1) but more additional and recommended non-statin therapy (Figure 1). PCPs used more of other, non-guideline recommended lipid lowering therapies such as niacin or fibrate as compared to specialists (10% vs. 6%, p=0.007).
The mean LDL was 3.3 mmol/L at baseline (visit 1) and decreased significantly to 2.4 and 2.2 mmol/L respectively during the follow up in visits 2 and 3 (11) , there was no difference in the extent of decrease between specialists and PCPs (Figure 2). The proportion of patients achieving the CCS recommended LDL-C level of < 2.0 mmol/L (primary endpoint) increased significantly to 41.7% and 50.8% in visits 2 and 3 respectively (11)and was similar between specialists and PCPs (Figure 3).
Physician responses as to why they were not following guidelines with respect to additional therapy of ezetimibe and/or PCSK9i are summarized in Figure 4; physicians did not provide reasons for not following the guidelines for each patient. The two most frequent reasons provided were patient refusal (more common by specialists) and additional therapy not perceived to be needed. Importantly, both groups of physicians (more often PCPs than specialists) stated that additional therapy would be prescribed at the next visit. Cost, as a reason for not following the guidelines was more commonly sited by PCPs while co-morbidities, patient intolerance, or social constraint was more frequently cited by specialists (Figure 4).
Multivariable analysis identified female gender, history of FH and chronic kidney disease as being associated with a lower likelihood of achieving recommended LDL-C level while age, coronary artery disease and diabetes as being predictors of achieving the recommended level. Care by a specialist vs. PCP was not significantly associated with achieving the recommended LDL-C level (1.02 [95% CI: 0.87-1.20] p=0.80). The use of any recommended lipid lowering therapy was the strongest indicator of achieving LDL-C < 2.0 mmol/L with the odds ration and 95% CI for statin 3.10 (2.54-3.78, p <.0001), ezetimibe 1.71 (1.46-2.01, p <.0001) and PCSK9i 17.21 (13.69-21.63, p <.0001).