Variation in the achievement of HbA1c , blood pressure and LDL cholesterol targets in type 2 diabetes in general practice and characteristics associated with risk factor control.

Abstract

To identify population, general practitioner, and practice characteristics associated with the achievement of HbA1c , blood pressure and LDL cholesterol targets, and to describe variation in the achievement of risk factor control. We conducted a cross-sectional survey of 9342 people with type 2 diabetes, 281 general practitioners and 77 general practices in Norway. Missing values (7.4%) were imputed using multiple imputation by chained equations. We used three-level logistic regression with the achievement of HbA1c , blood pressure and LDL cholesterol targets as dependent variables, and factors related to population, general practitioners, and practices as independent variables. Treatment targets were achieved for HbA1c in 64%, blood pressure in 50%, and LDL cholesterol in 52% of people with type 2 diabetes, and 17% met all three targets. There was substantial heterogeneity in target achievement among general practitioners and among practices; the estimated proportion of a GPs diabetes population at target was 55-73% (10-90 percentiles) for HbA1c , 36-63% for blood pressure, and 47-57% for LDL cholesterol targets. The models explained 11%, 5% and 14%, respectively, of the total variation in the achievement of HbA1c , blood pressure and LDL cholesterol targets. Use among general practitioners of a structured diabetes form was associated with 23% higher odds of achieving the HbA1c target (odds ratio 1.23, 95% confidence interval (CI) 1.02-1.47) and 17% higher odds of achieving the LDL cholesterol target (odds ratio 1.17, 95% CI 1.01-1.35). Clinical diabetes management is difficult, and few people meet all three risk factor control targets. The proportion of people reaching target varied among general practitioners and practices. Several population, general practitioner and practice characteristics only explained a small part of the total variation. The use of a structured diabetes form is recommended.