title: Case Numbers and Process Quality in Breast Surgery in Germany: A Retrospective Analysis of Over 150,000 Patients From 2013 to 2014.
abstract: BACKGROUND
  Numerous studies from around the world have shown a positive association between case numbers and the quality of medical care. The evidence to date suggests that conformity to guidelines for the treatment of patients with breast cancer is better in German hospitals that have higher case numbers.
  
  
  METHODS
  We used data obtained by an external program for quality assurance in inpatient care (externe stationäre Qualitätssicherung, esQS) for the years 2013 and 2014 to investigate seven process indicators in the area of breast surgery, including histologic confirmation of the diagnosis before definitive treatment, axillary dissection as recommended by the guidelines, and an appropriate temporal interval between diagnosis and operation. Case numbers were categorized with the aid of various threshold values. Moreover, subgroup analyses were carried out for patients under age 65, patients in good general health, patients without lymph-node involvement, and patients with a tumor size pT0 or pT1 or an overall tumor size less than 5 cm.
  
  
  RESULTS
  Data on 153,475 patients from 939 hospitals were analyzed. Six of seven indicators had values that were better overall, to a statistically significant extent, in hospitals with higher case numbers. Although this relationship was not consistently seen, the worst results were generally found in the category with the lowest case numbers. Similar though less striking results were obtained in the subgroup analyses. An exception to the general finding was that, in hospitals with higher case numbers, the interval between diagnosis and operation was more often longer than three weeks.
  
  
  CONCLUSIONS
  Guideline adherence is higher in hospitals that treat more cases. The present study does not address the question whether this, in turn, affects morbidity or mortality. To improve process quality in peripheral hospitals, the quality assurance program should be continued.
authors.affiliation: AQUA-Institute for Applied Quality Improvement and Research in Health Care GmbH, Göttingen, Department of Plastic, Reconstructive, and Breast Surgery, Städtisches Klinikum Görlitz gGmbH, Görlitz, Department of General Practice and Health Services Research, Heidelberg University Hospital.
authors.forename: Christina
authors.initials: C
authors.lastname: Köster
authors.forename: Günther
authors.initials: G
authors.lastname: Heller
authors.forename: Stephanie
authors.initials: S
authors.lastname: Wrede
authors.forename: Thomas
authors.initials: T
authors.lastname: König
authors.forename: Steffen
authors.initials: S
authors.lastname: Handstein
authors.forename: Joachim
authors.initials: J
authors.lastname: Szecsenyi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D005858:Germany / Q000453:epidemiology; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008408:Mastectomy / Q000592:standards* / Q000706:statistics & numerical data*; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care / Q000592:standards / Q000706:statistics & numerical data*; D015995:Prevalence; D019984:Quality Indicators, Health Care / Q000592:standards / Q000706:statistics & numerical data; D011787:Quality of Health Care / Q000145:classification / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D016387:Women's Health / Q000706:statistics & numerical data; D016526:Workload; D055815:Young Adult