Role of Patient and Practice Characteristics in Variance of Treatment Quality in Type 2 Diabetes between General Practices

BackgroundAccounting for justifiable variance is important for fair comparisons of treatment quality. The variance between general practices in treatment quality of type 2 diabetes (T2DM) patients may be attributed to the underlying patient population and practice characteristics. The objective of this study is to describe the between practice differences in treatment, and identify patient and practice level characteristics that may explain these differences.MethodsThe data of 24,607 T2DM patients from 183 general practices in the Netherlands were used. Treatment variance was assessed in a cross-sectional manner for: glucose-lowering drugs/metformin, lipid-lowering drugs/statins, blood pressure-lowering drugs/ACE-inhibitor or ARB. Patient characteristics tested were age, gender, diabetes duration, comorbidity, comedication. Practice characteristics were number of T2DM patients, practice type, diabetes assistant available. Multilevel logistic regression was used to examine the between practice variance in treatment and the effect of characteristics on this variance.ResultsTreatment rates varied considerably between practices (IQR 9.5–13.9). The variance at practice level was 7.5% for glucose-lowering drugs, 3.6% for metformin, 3.1% for lipid-lowering drugs, 10.3% for statins, 8.6% for blood pressure-lowering drugs, and 3.9% for ACE-inhibitor/ARB. Patient and practice characteristics explained 19.0%, 7.5%, 20%, 6%, 9.9%, and 13.4% of the variance respectively. Age, multiple chronic drugs, and ≥3 glucose-lowering drugs were the most relevant patient characteristics. Number of T2DM patients per practice was the most relevant practice characteristic.DiscussionConsiderable differences exist between practices in treatment rates. Patients’ age was identified as characteristic that may account for justifiable differences in especially lipid-lowering treatment. Other patient or practice characteristics either do not explain or do not justify the differences.背景 对合理差异进行考量，是公平比较治疗质量的关键环节。2型糖尿病（T2DM）患者的治疗质量在不同全科医疗机构间存在差异，此类差异可能源于患者基线人群特征与医疗机构自身属性。本研究旨在描述各医疗机构间的治疗差异，并识别可解释此类差异的患者及医疗机构层面特征。 方法 本研究使用了荷兰183家全科医疗机构的24607名T2DM患者数据。采用横断面研究方式评估以下治疗方案的差异：降糖药物/二甲双胍、调脂药物/他汀类药物、降压药物/血管紧张素转换酶抑制剂（ACE-inhibitor）或血管紧张素Ⅱ受体拮抗剂（ARB）。本次检验的患者特征包括年龄、性别、糖尿病病程、合并症、合并用药；医疗机构特征则涵盖T2DM患者数量、医疗机构类型、是否配备糖尿病专职助理。本研究采用多水平logistic回归分析，以考察不同医疗机构间的治疗差异，以及各类特征对该差异的影响。 结果 各医疗机构间的治疗率存在显著差异（四分位间距IQR：9.5~13.9）。医疗机构层面的方差分别为：降糖药物7.5%、二甲双胍3.6%、调脂药物3.1%、他汀类药物10.3%、降压药物8.6%、血管紧张素转换酶抑制剂/血管紧张素Ⅱ受体拮抗剂3.9%。患者与医疗机构特征分别可解释上述差异的19.0%、7.5%、20%、6%、9.9%及13.4%。其中，年龄、多重慢性用药及≥3种降糖药物为最具相关性的患者特征；单医疗机构T2DM患者数量为最具相关性的医疗机构特征。 讨论 不同全科医疗机构间的治疗率存在显著差异。患者年龄被证实为可合理解释调脂治疗差异的核心特征，其余患者或医疗机构特征要么无法解释此类差异，要么无法为差异提供合理依据。