Indicators on PBS drug prescribing misleading
Trend indicators for prescription drugs may be misleading to general practitioners, according to a study in the latest edition of the Medical Journal of Australia.
The study, led by David A Henry, Professor of Clinical Pharmacology, Faculty of Health, University of Newcastle, aimed to determine the possibility of using prescribing data, collected routinely by the Health Insurance Commission (HIC), to generate meaningful prescribing indicators for use in general practice.
A common prescribing "indicator" is the volume of prescribing by a doctor, where numbers of prescriptions are related to numbers of patients or consultations.
Australia is one of several countries that provide feedback of prescribing data to practitioners.
"HIC prescribing data are incomplete, and we were particularly interested in the effects of this on the validity of the prescribing indicators. Forty-three potentially useful indicators were identified. These covered a fairly narrow range of prescribing activities and many required additional clinical information for interpretation," says Professor Henry.
Two expert groups, consisting of GPs, clinical pharmacologists, physicians and pharmacists, reviewed 22 classes of drugs available on the Pharmaceutical Benefits Scheme, identifying issues of efficacy, safety and cost that might be reflected in prescribing indicators.
"Indicators based on prescribing rates gave a misleading picture of prescribing trends where the completeness of HIC data changed over time.
"We are particularly concerned that doctors practising in socially disadvantaged areas might be mistakenly identified as high prescribers, and criticised for this, says Professor Henry.
Professor Henry said to achieve a satisfactory level of validity and reliability, prescribing indicators need to be based on all prescriptions, irrespective of whether they attract a Commonwealth payment. The Government needed to change the current arrangements whereby data on prescriptions were only collected when a payment was made by the Commonwealth.
The Medical Journal of Australia is a publication of the Australian Medical Association.
CONTACT: Professor David Henry Fax (0011) 41 22 791 4167
Email: henryd@who.ch
Sarah Crichton, AMA (0419) 44 0076