The use of the ASTRO-PU and the ASTRO(97)-PU in the setting of prescribing budgets in English general practice

Objectives: To examine the variation in prescribing costs explained by the Age, Sex and Temporary Resident Originated Prescribing Unit (ASTRO-PU) and its replacement, the ASTRO (97)-PU, in order to determine the appropriateness of their use in the setting of prescribing budgets in English general practice. Methods: Linear regression analysis was used to analyse routinely collected patient and prescribing data from one English health authority (Lincolnshire Health) for the fiscal year 1995. Results: The goodness-of-fit of the regression models constructed varied according to whether practices had dispensing status (i.e. rural practices that have permission to dispense drugs to their own patients as a means of compensating for the lack of pharmacies in such areas), with the ASTRO-PU and ASTROP(97)-PU explaining a higher proportion of the variation in prescribing costs amongst practices with such status. Conclusions: This paper draws two main conclusions. First, the weights embodied in the ASTRO-PU and the ASTRO(97)-PU may have been biased by the number of dispensing practices sampled during their construction. Second, the denominators may be more applicable to dispensing practices, implying that primary care groups may need to follow the principle of ‘local flexibility’ during the budget-setting process.