Australian Statistics on Medicines 1997 Commonwealth Department of Health and Family Services Australian Statistics on Medicines 1997 i © Commonwealth of Australia 1998 ISBN 0 642 36772 8 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be repoduced by any process without written permission from AusInfo. Requests and enquiries concerning reproduction and rights should be directed to the Manager, Legislative Services, AusInfo, GPO Box 1920, Canberra, ACT 2601. Publication approval number 2446 ii FOREWORD The Australian Statistics on Medicines (ASM) is an annual publication produced by the Drug Utilisation Sub-Committee (DUSC) of the Pharmaceutical Benefits Advisory Committee. Comprehensive drug utilisation data are required for a number of purposes including pharmacosurveillance and the targeting and evaluation of quality use of medicines initiatives. It is also needed by regulatory and financing authorities and by the Pharmaceutical Industry. A major aim of the ASM has been to put comprehensive and valid statistics on the Australian use of medicines in the public domain to allow access by all interested parties. Publication of the Australian data facilitates international comparisons of drug utilisation profiles, and encourages international collaboration on drug utilisation research particularly in relation to enhancing the quality use of medicines and health outcomes. The data available in the ASM represent estimates of the aggregate community use (non public hospital) of prescription medicines in Australia. In 1997 the estimated number of prescriptions dispensed through community pharmacies was 179 million prescriptions, a level of increase over 1996 of only 0.4% which was less than the increase in population (1.2%). A readership survey was conducted in 1998 and it is hoped that some of the suggestions for improvement to the present format will be incorporated in the next edition of the ASM. Another option being considered is making summary utilisation data available via the Internet. Access to information on the indications for which drugs are prescribed, and the age and sex demographics of the patients receiving these prescriptions, will also be available in the near future from an ongoing survey of community medical practitioners. The ASM presents dispensing data on most drugs marketed in Australia and should be an interesting and valuable source of information for researchers working in health care and pharmaceutical services, both in Australia and overseas. D J Birkett Chairman Drug Utilisation Sub-Committee iii iv CONTENTS INTRODUCTION 1 INFORMATION ON THE AUSTRALIAN STATISTICS ON MEDICINES 2 Drug Utilization Sub-Committee 3 Drug classification 6 ATC system main groups 6 Measurement unit 7 Health Insurance Commission processing 8 Pharmacy Guild Survey data 8 Combined database 9 Drug utilisation trends 12 Tables in the Australian Statistics on Medicines 16 References 16 CAVEATS 17 GLOSSARY OF TERMS 18 Weights and measures 19 ATC & DDD CHANGES 1998 20 TABLE 1 1997 COMMUNITY PRESCRIPTION NUMBERS, TOGETHER WITH GOVERNMENT AND PATIENT COSTS FOR SUBSIDISED DRUGS 23 TABLE 2 COMMUNITY PRESCRIPTION DRUG USE, IN DDDs/1000/DAY, FOR 1995 TO 1997 167 ATC INDEX 249 v LIST OF TABLES Table A: Prescription numbers by ATC groups 12 Table B: Top 10 drugs by defined daily dose/thousand population/day, 1997 13 Table C: Top 10 drugs by prescription counts, 1997 14 Table D: Top 10 drugs by cost to government, 1997 14 LIST OF FIGURES Figure A: Community utilisation of enalapril 10 Figure B: Community utilisation of atenolol 10 Figure C: Number of prescriptions by type of service 13 Figure D: Top 10 subsidised drugs dispensed in 1997 15 Figure E: Top 10 non-subsidised drugs dispensed in 1997 15 Figure F: H2-receptor antagonists 171 Figure G: Other drugs used for treatment of peptic ulcer 171 Figure H: Drugs used in the management of hypertension 187 Figure I: Serum lipid reducing drugs, by class 195 Figure J: Serum lipid reducing drugs, individual 195 Figure K: Penicillins and macrolides 211 Figure L: Other selected antibacterial drugs 211 Figure M: Non steroidal anti-inflammatory drugs (NSAIDs) 220 Figure N: Psychotherapeutic medications 234 Figure O: Selected antidepressants 234 Figure P: Anti-asthmatic drugs 242 vi INTRODUCTION The data contained in the 1997 ASM are drawn from two sources. The first is the Health Insurance Commission records of prescriptions submitted for payment of a subsidy under the Pharmaceutical Benefits and Repatriation Pharmaceutical Benefits Schemes (PBS/ RPBS). The second is an ongoing survey of a representative sample of community pharmacies, which provides an estimate of the non-subsidised use of prescription medicines in the Australian community. The usage of prescription medicines dispensed in public hospitals is not available in this report. The units of measurement are the prescription and the defined daily dose per 1000 population per day (DDD/1000/day). The defined daily dose is established by the WHO Collaborating Centre for Drug Statistics Methodology on the basis of the assumed average dose per day of the drug, used for its main indication by adults. The drugs presented in this publication are arranged using the Anatomical Therapeutic Chemical (ATC) classification system. For more detail on this classification and the unit of measurement, please read the chapter ‘Information on the Australian Statistics on Medicines’. The data are presented in two major tables. Table 1 includes 1997 community (i.e. subsidised and non-subsidised) prescription numbers, together with the government and patient costs for the PBS-listed drugs only. The cost information for the PBS listed drugs includes a component which estimates the under copayment cost based on PBS experience with that drug. Cost information on the dispensing of drugs not listed on the PBS is not available. Table 2 includes community prescription drug use, in DDDs/1000/day, for the years 1995 to 1997. 1 INFORMATION ON THE AUSTRALIAN STATISTICS ON MEDICINES In order to work towards the more rational and cost-effective use of medication in society, it is essential to have accurate information on patterns of drug prescription and use. Where this use is found to be inappropriate, drug utilisation data can monitor the impact of educational or regulatory interventions and can guide the interpretation of pharmacoeconomic analysis (1). In Australia around 75% of all community (i.e. non-public hospital) prescriptions are dispensed under one of 2 subsidisation schemes - the PBS and the Repatriation Pharmaceutical Benefits Scheme (RPBS). These schemes were established to provide the general community (PBS) and returned servicemen and women (RPBS) with access to necessary medicinal products, which are affordable, available and of acceptable standards. In 1996 the RPBS was 7% of the size of the PBS, however over 90% of the RPBS prescriptions involved PBS listed drugs. In Australia, a new medicinal drug must gain approval for supply in accord with the requirements of the Therapeutic Goods Act 1989. Approval is also required to extend the indications of an established drug. Applications are dealt with by the Therapeutic Goods Administration and, for prescription drugs, advice is sought from an expert committee, the Australian Drug Evaluation Committee (ADEC). Once a prescription drug is approved for marketing, the company concerned usually applies to have the drug listed on the PBS. This is the national scheme available to the Australian community, for subsidising the cost of pharmaceuticals. Because of the attraction of the scheme to consumers, it is usually necessary for the company to have the drug listed on the scheme for viable marketing to occur. It is the Pharmaceutical Benefits Advisory Committee (PBAC) that recommends what drugs are to be listed on the scheme. Whereas the premarket evaluation addresses the issues of quality, safety and efficacy, the PBAC considers effectiveness and cost-effectiveness of the product relative to other alternatives. Once listing has been agreed to by the Government, the price of the drug is negotiated with the company by the Pharmaceutical Benefits Pricing Authority. The Authority consists of government, industry and consumer representatives. Under the PBS, general patients pay the cost of a prescription up to a maximum of $20.00 (as at July 1997). Pensioner and concessional patients pay $3.20 per script. There is a safety net to protect people with high medication needs. Once general patients (and their immediate family) have incurred $612.60 worth of PBS expenditure (indexed) in any 2 calendar year, prescriptions for the remainder of the year cost $3.20. Once pensioners and concessionals have incurred $166.40 worth of expenditure (indexed) in the calendar year, they receive all remaining prescriptions free of charge. Patients may also be required to pay a surcharge where the doctor prescribes a more expensive brand of an item, when there are cheaper, equivalent brands of that item in the PBS. As the general patient copayment rises, the dispensed price of many of the cheaper medications falls under this level and in such cases the patient pays the full price and no claim for payment is transmitted under the PBS. In 1997 the under copayment general prescriptions represented around 19.1% of all community prescribing. As well as this, there are many drugs that are not listed on the PBS or RPBS and are available only on private prescription with the patient paying the full cost