title: Factors influencing PRN medication use in nursing homes.
abstract: OBJECTIVE
  To identify determinants of PRN (as needed) drug use in nursing homes. Decisions about the use of these medications are made expressly by nursing home staff when general medical practitioners (GPs) prescribe medications for PRN use.
  
  
  METHODS
  Cross-sectional drug use data were collected during a 7-day window from 13 Australian nursing homes. Information was collected on the size, staffing-mix, number of visiting GPs, number of medication rounds, and mortality rates in each nursing home. Resident specific measures collected included age, gender, length of stay, recent hospitalisation and care needs.
  
  
  METHODS
  The number of PRN orders prescribed per resident and the number of PRN doses given per week averaged over the number of PRN medications given at all in the seven-day period.
  
  
  RESULTS
  Approximately 35% of medications were prescribed for PRN use. Higher PRN use was found for residents with the lower care needs, recent hospitalisation and more frequent doses of regularly scheduled medications. With increasing length of stay, PRN medication orders initially increased then declined but the number of doses given declined from admission. While some resident-specific characteristics did influence PRN drug use, the key determinant for PRN medication orders was the specific nursing home in which a resident lived. Resident age and gender were not determinants of PRN drug use.
  
  
  CONCLUSIONS
  The determinants of PRN drug use suggest that interventions to optimize PRN medications should target the care of individual residents, prescribing and the nursing home processes and policies that govern PRN drug use.
authors.affiliation: Therapeutics Research Unit, School of Medicine, University of Queensland, Princess Alexandra Hospital, Ipswich Rd, Woolloongabba, Queensland 4102, Australia. julies@soms.uq.edu.au
authors.forename: Julie A
authors.initials: JA
authors.lastname: Stokes
authors.forename: David M
authors.initials: DM
authors.lastname: Purdie
authors.forename: Michael S
authors.initials: MS
authors.lastname: Roberts
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D011307:Drug Prescriptions; D004359:Drug Therapy, Combination; D004363:Drug Utilization; D005260:Female; D006304:Health Status; D006801:Humans; D007902:Length of Stay; D008297:Male; D009726:Nurses; D009735:Nursing Homes / Q000706:statistics & numerical data*; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D012737:Sex Factors; D000078329:Workforce
chemical_list: D004364:Pharmaceutical Preparations