title: Application of concentration ratios to analyze the phenomenon of "next-door" pharmacy in Taiwan.
abstract: BACKGROUND
  In Taiwan, a policy of separation of prescribing and dispensing practices of practitioners at Western medical and dental clinics was implemented on an incremental basis in 1997. The purpose of this policy was to promote pharmacists' autonomy and increase the transparency and safety of prescribing medications. To avoid profit loss from no longer being able to dispense prescription medications, some clinics opened pharmacies located under the same roof as the clinic ("next-door" pharmacies) or hired an on-site pharmacist. This practice might compromise pharmacists' professional autonomy and patients' benefit in pharmaceutical care.
  
  
  OBJECTIVE
  The aim of the current study was to clarify the relationship between practicing pharmacies and clinics that resulted from contracts between pharmacies and the Bureau of National Health Insurance from 1996 to 2004.
  
  
  METHODS
  The National Health Research Institutes database in Taiwan supplied the complete claims data sets of practicing pharmacies from 1997 to 2004. The prescribing source of every dispensed prescription was used to calculate the 1-firm concentration ratio (CR-1) (ie, the proportion of prescriptions issued by the largest prescribing clinic/hospital in the total number of dispensed prescriptions of a pharmacy in each year). Similar processing was applied to the clinics. We identified each clinic's largest cooperating pharmacy and compared their CR-1s. Pharmacies that dispensed >900 prescriptions/mo during the study period were considered thriving. Pharmacies with a CR-1 > or =0.99 and whose largest cooperating clinic had a CR-1 > or =0.99 were considered to have a close business relationship, possibly indicating a next-door pharmacy.
  
  
  RESULTS
  The total number of prescriptions dispensed at all pharmacies in the database grew from 226,901 in 1996 to 59,785,039 in 2004, and the number of pharmacies, from 481 to 3529. An increasing number of pharmacies had a higher CR-1 after 1999. We found that most prescriptions could be dispensed at only 1 pharmacy during the study period. In 2004, 1429 clinics had >900 prescriptions/mo dispensed externally and a CR-1 > or =0.99. They had released 75.8% of all prescriptions to be dispensed at practicing pharmacies; 811 of these clinics had a cooperating pharmacy with a CR-1 > or =0.99.
  
  
  CONCLUSIONS
  In this data analysis in Taiwan, most prescriptions from practitioners at Western medical and dental clinics could be dispensed at only 1 pharmacy during the study period, suggesting that pharmacists' professional autonomy and the patients' benefit in pharmaceutical care might be compromised in Taiwan.
authors.affiliation: Department of Family Medicine, Taipei Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan. Electronic address: tjchen@vghtpe.gov.tw.
authors.forename: Tzeng
authors.initials: T
authors.lastname: Ji Chen
authors.affiliation: Department of Public Finance, National Chengchi University, Taipei, Taiwan.
authors.forename: Li-Fang
authors.initials: LF
authors.lastname: Chou
authors.affiliation: Department of Family Medicine, Taipei Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Shinn Jang
authors.initials: SJ
authors.lastname: Hwang
mesh_terms: D000554:Ambulatory Care Facilities; D011307:Drug Prescriptions; D006801:Humans; D009313:National Health Programs; D010594:Pharmacies; D010595:Pharmacists; D017009:Professional Autonomy; D013624:Taiwan