title: Relationship between hospital volume and hemorrhagic complication after percutaneous renal biopsy: results from the Japanese diagnosis procedure combination database.
abstract: BACKGROUND
  Although hemorrhagic complications are major complications of percutaneous renal biopsy (PRB), the relationship between procedure volume and morbidity remains unclear for PRB. The present study investigated the impact of hospital volume on the occurrence of hemorrhagic complications after PRB.
  
  
  METHODS
  Using large claims-based data in the diagnosis procedure combination database in Japan, we identified inpatients with renal disorders who underwent PRB within 4 days after admission during July to December 2007 to 2010. We assessed patient age, sex, clinical syndromes, hemorrhagic complications and diagnoses, and annual hospital volume of PRB divided into quintiles. Multivariate logistic regression analyses fitted with a generalized estimation equation were performed accounting for within-hospital clustering.
  
  
  RESULTS
  A total of 15,191 patients were identified from 942 hospitals. The overall proportion of hemorrhagic complications was 2.1 %, including diagnoses of hemorrhagic events (1.6 %), red blood cell transfusion (0.5 %), and requiring angiography or endovascular procedure (0.1 %). In-hospital deaths attributable to the complications occurred in 0.06 % of the patients. Patients with rapidly progressive nephritic syndrome (odds ratio 3.41, 95 % confidence interval 2.22-5.25) had significantly higher incidence than those with chronic nephritic syndrome. No significant association was observed between hospital volume and hemorrhagic complications, with odds ratios for the low-intermediate, intermediate, intermediate-high, and high-volume groups relative to the low-volume group of 0.74 (0.43-1.26), 1.19 (0.74-1.92), 1.16 (0.67-2.00), and 1.35 (0.78-2.34), respectively.
  
  
  CONCLUSIONS
  No significant relationship was observed between hemorrhagic complication incidence and hospital volume regarding PRB.
authors.affiliation: Department of Health and Social Behavior, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamura
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Horiguchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
mesh_terms: D058186:Acute Kidney Injury / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001706:Biopsy / Q000009:adverse effects; D005260:Female; D006417:Hematuria / Q000473:pathology; D017052:Hospital Mortality; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data*; D061846:Hospitals, Low-Volume / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000473:pathology*; D007674:Kidney Diseases / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000473:pathology; D019106:Postoperative Hemorrhage / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D051436:Renal Insufficiency, Chronic / Q000473:pathology; D012307:Risk Factors; D055815:Young Adult