Pharmacological primary and secondary cardiovascular prevention among diabetic patients in a multiethnic general practice population: still room for improvements

Background: Ethnic minority groups have higher prevalence of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). We assessed general practitioners' (GPs') performance with respect to the pharmacological prevention of CVD in patients with T2DM from different ethnic backgrounds in Oslo. Methods: Of 1653 T2DM patients cared for by 49 GPs in 2005, 380 had a diagnosis of CVD. Ethnicity was categorized as Norwegian, South Asian and other. Risk factor levels, medication use, achievement of treatment targets (HbA1c <= 7.5%, systolic blood pressure (SBP) <= 140 mmHg, total cholesterol/HDL-cholesterol < 4) and therapeutic intensity (number of drugs targeting each risk factor) were recorded. Chi-square, Wald tests and multiple linear regression analyses were used. Results: Of the 1273 patients receiving primary prevention, 1.5% had their Hb1Ac, 4.8% SBP and 12.7% lipids levels above treatment thresholds without relevant prescriptions. Among patients on pharmacological therapy, 66% reached the HbA1c, 62% SBP and 62% lipid target. Proportions not achieving the HbA1c target were 26% in Norwegians, 38% in South Asians and 29% in others (p = 0.008). Proportions not achieving the SBP target were 42% in Norwegians, 22% in South Asians and 25% in others (p <= 0.001). Of those not achieving the HbA1c and SBP targets, 43% and 35% respectively, used only one agent. In secondary prevention, 0.8% of the patients had their HbA1c, 0.5% SBP and 7.4% lipid levels above treatment thresholds without relevant prescriptions. Among patients on pharmacological therapy, 65% reached the HbA1c, 64% SBP and 66% lipid target. Proportions not achieving the HbA1c target were 26% in Norwegians, 47% in South Asians and 40% in others (p = 0.03). Proportions not achieving the SBP target were 36% in Norwegians, 22% in South Asians and 56% in others (p = 0.050). Of those not achieving HbA1c and SBP targets, 49% and 21% respectively, were on mono-therapy. Conclusions: Norwegian GPs comply reasonably well with guidelines for pharmacological prevention of CVD in T2DM patients across ethnic groups. However, lipid-lowering therapy was generally underused, and the achievement of treatment targets for HbA1c in ethnic minorities and for BP in Norwegians could be improved.