title: Association between Nurse Staffing and In-Hospital Bone Fractures: A Retrospective Cohort Study.
abstract: To determine if sufficient nurse staffing reduced in-hospital fractures in acute care hospitals.
  
  
  
  The Japanese Diagnosis Procedure Combination inpatient (DPC) database from July 2010 to March 2014 linked with the Surveys for Medical Institutions.
  
  
  
  We conducted a retrospective cohort study to examine the association of inpatient nurse-to-occupied bed ratio (NBR) with in-hospital fractures. Multivariable logistic regression with generalized estimating equations was performed, adjusting for patient characteristics and hospital characteristics.
  
  
  
  We identified 770,373 patients aged 50 years or older who underwent planned major surgery for some forms of cancer or cardiovascular diseases. We used ICD-10 codes and postoperative procedure codes to identify patients with in-hospital fractures. Hospital characteristics were obtained from the "Survey of Medical Institutions and Hospital Report" and "Annual Report for Functions of Medical Institutions."
  
  
  
  Overall, 662 (0.09 percent) in-hospital fractures were identified. Logistic regression analysis showed that the proportion of in-hospital fractures in the group with the highest NBR was significantly lower than that in the group with the lowest NBR (adjusted odd ratios, 0.67; 95 percent confidence interval, 0.44-0.99; p = .048).
  
  
  
  Sufficient nurse staffing may be important to reduce postsurgical in-hospital fractures in acute care hospitals.
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Morita
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Health Policy and Informatics, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
mesh_terms: D050723:Fractures, Bone / Q000209:etiology / Q000517:prevention & control*; D006761:Hospitals; D006801:Humans; D007564:Japan; D009741:Nursing Staff, Hospital / Q000706:statistics & numerical data*; D010561:Personnel Staffing and Scheduling; D011183:Postoperative Complications / Q000517:prevention & control; D019984:Quality Indicators, Health Care; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: Administrative data uses; cohort analysis; nursing; quality of care/patient safety (measurement)