title: Old habits die hard: a nationwide utilization study of short-acting nifedipine in Taiwan.
abstract: BACKGROUND
  To investigate the nationwide trend of ambulatory prescriptions of short-acting nifedipine on a PRN (pro re nata) order over a fifteen-year period in Taiwan.
  
  
  METHODS
  The systematic sampling claims datasets (0.2% sampling ratio) of ambulatory care visits within Taiwan's National Health Insurance from 1997 to 2011 were analyzed. The prescriptions of short-acting capsule-form nifedipine on a PRN order were stratified by the patient's age, the prescribing physician's specialty, and the setting of healthcare facility for each year.
  
  
  RESULTS
  During the study period, 8,189,681 visits were analyzed. While the utilization rate of calcium channel blockers changed with time from 2.8% (13,767/489,636) in 1997 to 5.1% (31,349/614,719) in 2011, that of short-acting nifedipine were from 1.0% (n = 5,070) to 0.2% (n = 1,246). However, short-acting capsule-form nifedipine on a PRN order still existed (from 447 prescriptions in 1997 to 784 in 2011). More than one half of these PRN nifedipines were prescribed by the internists and to the elderly patients; almost four-fifths of PRN nifedipines were prescribed during non-emergent consultations.
  
  
  CONCLUSIONS
  The physicians in Taiwan still had the habit of prescribing short-acting nifedipines for PRN use. The reason for such practices and the impact on patients' health deserve attention.
authors.affiliation: Department of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chia-Lin
authors.initials: CL
authors.lastname: Chou
authors.affiliation: Department of Critical Care Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Department and Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan; College of Pharmacy, Taipei Medical University, Taipei, Taiwan; Department of Internal Medicine, School of Medicine, National Defense Medical Center, Taipei, Taiwan; Department of Medicine, Tzu Chi University, Hualian, Taiwan.
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Chou
authors.affiliation: Department of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Hsu
authors.affiliation: Department of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Critical Care Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Department and Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yueh-Ching
authors.initials: YC
authors.lastname: Chou
authors.affiliation: Institute of Hospital and Health Care Administration, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Tzeng-Ji
authors.initials: TJ
authors.lastname: Chen
authors.affiliation: Department of Public Finance, National Chengchi University, Taipei, Taiwan.
authors.forename: Li-Fang
authors.initials: LF
authors.lastname: Chou
mesh_terms: D000553:Ambulatory Care / Q000706:statistics & numerical data*; D016208:Databases, Factual; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D006801:Humans; D009313:National Health Programs; D009543:Nifedipine / Q000627:therapeutic use; D010818:Practice Patterns, Physicians'; D062486:Public Health Surveillance; D013624:Taiwan
chemical_list: D009543:Nifedipine