Dear Editor

Watkins and colleagues[1] add to the growing literature on the many and varied influences on general practitioner prescribing behaviour and costs.[2,3] They argue, from the results of their analyses, that the dispensing status of the general practitioner is a statistically significant predictor associated with high prescribing costs, though it is unclear from their report exactly how many dispensing practices are involved and the numbers in each prescribing cost category. One difficulty with the attribute of dispensing status is that practices are classed as such if they dispense for just a small proportion of their registered population or if they dispense to all the registered population, and we do not know to what extent this variable influences prescribing costs.

The authors point out that dispensing doctors, because of the need to operate their dispensary as a business, are likely to have better knowledge of drug costs than their non-dispensing colleagues. In addition, they are more likely to restrict repeat prescribing quantities to 28 days’ worth, as opposed to the two or three months’ worth that non-dispensing practices commonly issued at the time of the study. In theory this greater overall control over repeat prescribing should exert downward pressure on costs by controlling medicine wastage arising from patient demand for unnecessary repeat medication. Work carried out in Cornwall and Isles of Scilly supports the notion that the prescribing costs of dispensing practices are similar to, if not slightly less than, those of non- dispensing practices.[4] In addition, aggregate data from the Prescription Pricing Authority show, for Cornish practices, that the cost per person of prescriptions arising from dispensing practices is consistently lower than that of prescriptions originating from non- dispensing practices, and this has been the case for many years.

References

(1) Watkins C, Harvey I, Carthy P, Moore L, Robinson E, Brawn R. Attitudes and behaviour of general practitioners and their prescribing costs: a national cross sectional study. Qual Saf Health Care 2003;12:29-34.

(2) Jacoby A, Smith M, Eccles M. A qualitative study to explore influences on general practitioners’ decisions to prescribe new drugs. Br J Gen Prac 2003;53:120-125.

(3) Jaye C, Tilyard M. A qualitative comparative investigation of variation on general practitioners’ prescribing patterns. Br J Gen Prac 2002;52:381-386.

(4) Wilcock M. Dispensing doctors and non-dispensing doctors - a comparison of their prescribing costs. Int J Pharm Prac 2001;9:197-202.