Use of guideline-recommended drug therapy in patients undergoing percutaneous coronary intervention for stable coronary heart disease in Germany: a multilevel analysis of nationwide routine data

OBJECTIVES: To determine the prescription of guideline recommended drug therapy in patients with stable coronary heart disease (sCHD) prior to percutaneous coronary intervention (PCI) in Germany and to examine the role of patient characteristics and features of regional healthcare supply in a multilevel model. DESIGN: Secondary data analysis of factors associated with the prescription of guideline recommended drug therapy using a multilevel model to analyse regional-level effects, over and above the effects of patient-level demographic and health status. SETTING: Office-based prescriptions in the year prior to the invasive procedure. PARTICIPANTS: A linked nationwide dataset from Germany's three largest statutory health insurance funds of all patients receiving PCI in the year 2016. MAIN OUTCOME MEASURES: Patients' odds of receiving optimal medical therapy and symptom-oriented therapy within 1 year prior to PCI. RESULTS: 68.6% of patients received at least one lipid-lowering drug and one symptom-oriented therapy prior to PCI. 43.6% received at least two agents to control their symptoms. Patients who received treatment in accordance with the recommendations had a greater number of diagnosed risk factors, a more severe history of cardiac disease and used a higher volume of ambulatory office-based physician services. The prescriptions prevalence for the symptom-oriented therapies differed significantly between eastern and western Germany, with a higher prevalence in the eastern districts. CONCLUSIONS: Guidelines can only provide decision-making corridors, and the applicability of recommendations must always be assessed on a case by case basis. Nevertheless, our analysis indicates that the prevalence of prescriptions in routine practice is subject to substantial variation and that conservative therapy options are not fully exhausted prior to PCI. This suggests that there might be room for improvement in the care of patients with sCHD.