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Prescribing Data

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Lesson 2 of 13
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Standardisation of prescribing

Watch the video below before moving on to the ASTRO-PU and STAR-PU sections below.

Video describing prescribing units

Please click on each section below to see more information.

  • Age
  • Sex
  • Temporary
  • Resident
  • Oriented
  • Prescribing
  • Unit
Comparing apples and oranges

ASTRO-PUs are used to ‘normalise’ prescribing data and allow us to compare practices and CCGs on a fairer basis.

  • Used to weight prescribing information to allow information users to compare prescribing in different practices based on individual practice populations.
  • Applied based on the practice populations for age, sex and patients aged 65.
  • Used to include temporary residents, however, this information is no longer available after June 2009.
  • Usually based on cost but there are weights based on number of items.

ASTRO-PUs – a worked example

Imagine 2 separate practices, both with 20,000 patients on their respective lists. You might reasonably expect them to have broadly similar prescribing activity and associated costs.

However, as can be seen from the chart, the distribution of patients across the 9 age bands between the 2 practices is markedly different.

In this example, Practice A (blue) could be a main practice near a university campus, whereas Practice B (orange) could be a sleepy seaside village with a disproportionately high number of retirees.

The weightings for these different age groups is very broad. For example, males aged between 0 and 4 count as 1 prescribing unit, whereas males over 75 count as over 11 units.

Assuming a 50:50 even split of males to females across all age groups for both practices, in our example Practice A would have a total of around 50,000 PUs compared to Practice B of around 87,000 – over 70% higher!

Specific Therapeutic Group, Age-Related Prescribing Unit

STAR-Pus are specific therapeutic group age-sex related prescribing units. Further developing and refining the principles of ASTRO-PUs, STAR-PUs focus on 8 key therapeutic groups, which account for 85% of all prescribing in England.

They are based on costs in specific therapeutic areas, e.g. the number of items per STAR-PU for antibiotics is a measure of prescribing quality.

STAR-PUs are available for the following therapeutic groups:

  1. Gastrointestinal
  2. Cardiovascular
  3. Respiratory
  4. Central Nervous System (CNS)
  5. Infection
  6. Endocrine
  7. Musculoskeletal
  8. Skin

These areas can be further sub-divided. For example, within CNS there are:

  • Hypnotics
  • Anxiolytics
  • Antidepressants
  • Antiemetics
  • Analgesics
  • Acute migraine
  • Antiepileptics
  • Parkinson’s medication

STAR-PUs are particularly useful for groups of drugs which are specifically for one sex or used for a distinct age band. The number of items per STAR-PU for antibiotics is a measure of prescribing quality.