title: Use of ATC to describe duplicate medications in primary care prescriptions.
abstract: OBJECTIVE
  We aimed to demonstrate the suitability of the Anatomical Therapeutic Chemical Classification (ATC) to describe duplicate drugs and duplicate drug classes in prescription data and describe the pattern of duplicates from public and private primary care clinics of Kuala Lumpur, Malaysia.
  
  
  METHODS
  We analyzed prescription data year 2005 from all 14 public clinics in Kuala Lumpur with 12,157 prescriptions, and a sample of 188 private clinics with 25,612 prescriptions. As ATC Level 5 code represents the molecule and Level 4 represents the pharmacological subgroup, we used repetitions of codes in the same prescription to describe duplicate drugs or duplicate drug classes and compared them between the public and private clinics.
  
  
  RESULTS
  At Level 4 ATC, prescriptions with duplicates drug classes were 1.46% of all prescriptions in private and 0.04% in public clinics. At Level 5 ATC, prescriptions with duplicate drugs were 1.81% for private and 0.95% for public clinics. In private clinics at Level 5, 73.3% of prescriptions with duplicates involved systemic combination drugs; at Level 4, 40.3% involved systemic combination drugs. In the public sector at Level 5, 95.7% of prescriptions with duplicates involved topical products.
  
  
  CONCLUSIONS
  Repetitions of the same ATC codes were mostly useful to describe duplicate medications; however, we recommend avoid using ATC codes for tropical products for this purpose due to ambiguity. Combination products were often involved in duplicate prescribing; redesign of these products might improve prescribing quality. Duplicates occurred more often in private clinics than public clinics in Malaysia.
authors.affiliation: Clinical Research Centre, Ministry of Health Malaysia, Level 3 Dermatology Block, Hospital Kuala Lumpur, Jalan Pahang, 50586, Kuala Lumpur, Malaysia. chiaomei@yahoo.com
authors.forename: Chiao Mei
authors.initials: CM
authors.lastname: Lim
authors.forename: Faridah
authors.initials: F
authors.lastname: Aryani Md Yusof
authors.forename: Sharmini
authors.initials: S
authors.lastname: Selvarajah
authors.forename: Teck Onn
authors.initials: TO
authors.lastname: Lim
mesh_terms: D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004363:Drug Utilization; D017723:Drug Utilization Review; D019538:Health Care Surveys / Q000379:methods; D006801:Humans; D008296:Malaysia; D004364:Pharmaceutical Preparations / Q000145:classification*; D011320:Primary Health Care / Q000706:statistics & numerical data*; D017149:Private Sector; D017150:Public Sector
chemical_list: D004364:Pharmaceutical Preparations