title: Evaluating methods for intersectoral comparison of quality of care. A routine data analysis of elective percutaneous coronary interventions.
abstract: OBJECTIVE
  To compare the quality of care regarding the use of elective percutaneous coronary interventions (PCIs) in the inpatient and outpatient setting and to evaluate different methods of confounder control in this context.
  
  
  METHODS
  Based on data of three statutory health insurances including more than nine million insurance members, a retrospective cohort study between 2005 and 2009 was conducted. The occurrence of myocardial infarction, stroke, further coronary intervention and death was ascertained following the first PCI in the study period, which was preceded by a one-year period without a PCI. A Cox proportional hazard model was used to assess the influence of the setting of the elective PCI on the risk for complications after the PCI for each outcome separately. Age, sex, the number of diseases of the Elixhauser comorbidity measure, past acute coronary syndrome, coronary artery disease, dyslipidemia, past stroke, past coronary artery bypass surgery and the year of the PCI were included as covariables. The analyses were repeated in a propensity score matched cohort as well as in inverse probability of treatment weighted analyses.
  
  
  RESULTS
  The cohort comprised 4,269 patients with an outpatient PCI and 26,044 patients with an inpatient PCI. The majority of the analyses revealed no statistically significant effect of the setting of the PCI on the risk of myocardial infarction, stroke and further coronary interventions, whereas a reduced mortality risk was observed for outpatient PCIs. Similar results were obtained in the propensity score analyses.
  
  
  CONCLUSIONS
  The analysis revealed that the adjusted risk for complications following an elective PCI is similar between the inpatient and the outpatient setting. For mortality the risk differed but this might be explained by residual or unmeasured confounding. The different methods applied in this study revealed mostly similar results. Since our study only covered one aspect of quality of care in the field of PCI and did not consider drug treatment in hospital or in the outpatient setting, further studies are needed which include these aspects.
authors: C
authors: C
authors: Ohlmeier
authors: R
authors: R
authors: Linder
authors: D
authors: D
authors: Enders
authors: R
authors: R
authors: Mikolajczyk
authors: W
authors: W
authors: Haverkamp
authors: D
authors: D
authors: Horenkamp-Sonntag
authors: Prof. Dr. Edeltraut Garbe, Leibniz Institute for Prevention Research and Epidemiology - BIPS, Head of Department of Clinical Epidemiology, Achterstraße 30, 28359 Bremen, Germany, E-mail: garbe@bips.uni-bremen.de.
authors: E
authors: E
authors: Garbe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000555:Ambulatory Care Information Systems; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000592:standards*; D015331:Cohort Studies; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D003625:Data Collection; D005260:Female; D005858:Germany; D006751:Hospital Information Systems; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D009313:National Health Programs; D017063:Outcome Assessment, Health Care; D011787:Quality of Health Care / Q000592:standards*; D012189:Retrospective Studies; D020521:Stroke / Q000209:etiology*
keywords: Percutaneous coronary intervention; methods for confounder control; outpatient and inpatient care; quality of health care