BMJ No 7121 Volume 315
Information in Practice Saturday 6 December 1997
What can PACT tell us about prescribing in general practice?
Azeem Majeed, Norman Evans, Paula Head
Prescribing is important to general practitioners. Most consultations with a general practitioner result in a prescription being issued, and in 1995 general practitioners in the United Kingdom issued about 550 million prescriptions. The total cost of these prescriptions was £4700m, 11% of all NHS spending in 1995. Unsurprisingly, the general practice prescribing budget is seen by many managers and health economists as an area where there is scope for considerable savings through more cost effective prescribing.(1, 2) Hence, general practitioners are likely to be increasingly called on to defend their prescribing patterns.
| Summary points |
| PACT (prescribing analyses and cost) data are derived from prescriptions issued by general practitioners |
| PACT data have been used by health authorities as a managerial tool, by health services researchers, and, more recently, by general practitioners to audit and to help improve their prescribing |
| The recent availability of electronic PACT data on the prescribing of individual drugs has allowed health authorities to look at prescribing in more detail and to develop prescribing indicators |
| To make more effective use of PACT, general practitioners who wish to examine their prescribing in more detail should be given access to electronic PACT data and be trained in its analysis and interpretation |
In England the main source of information on general
practitioners' prescribing is PACT (prescribing analyses and cost),
and similar schemes exist in Scotland and Wales. Although PACT was
first introduced in 1988, many general practitioners have made little
use of PACT data. Because of the importance and potential value of such
data, general practitioners need to be aware of the information
available via PACT and how this information is used by health
authorities' medical and p
PACT - Prescribing analyses and cost. Information
on general practitioners' prescribing obtained from prescriptions
dispensed by community pharmacists, dispensing general practitioners,
and appliance contractors
PPA - Prescription Prescribing Authority. Located
in Newcastle, the PPA is the source of PACT data PUs - Prescribing units. A measure of patients'
needs for prescribed drugs weighted for age; patients aged under 65
years count as one unit, patients aged 65 and over count as three units
ASTRO-PUs - Age, sex, and temporary resident
originated prescribing units. A more sophisticated measure of
patients' needs for prescribed drugs than prescribing units STAR-PUs - Specific therapeutic group age-sex
related prescribing units. Measures of patients' needs for prescribed
drugs in specific therapeutic areas. These are not yet in widespread
use Defined daily doses - A measure of the amount of
drug prescribed based on standard therapeutic units. The number of
defined daily doses is calculated by dividing the total amount of a
drug prescribed by the defined daily dose for the drug. For example,
the defined daily dose of ranitidine is 300 mg. If a practice
prescribed a total of 186,000 mg of ranitidine, this would equal 620
defined daily doses (186,000/300) PACTLINE - An electronic link between health
authorities and the PPA which allows health authorities to download
computerised prescribing data about the prescribing of their general
practices HEAPACT - Health authority electronic PACT. An
enhanced version of PACTLINE which allows health authorities to obtain
computerised information about the prescribing of individual drugs EPACT - Electronic PACT. A unified system that
will replace PACTLINE and HEAPACT
The Prescription Prescribing Authority (PPA) collects information
on all prescriptions issued by general practitioners that are dispensed
by community pharmacists, dispensing general practitioners, or
appliance contractors. The information collected includes the name and
cost of the drug and the number of items dispensed (an item is defined
as each preparation on the prescription). The drugs dispensed are then
used to calculate the cost of each item, and the information is entered
onto computer by the PPA. Drugs are categorised by the section of the
British National Formulary that they fall in. Hence,
information is available for individual drugs (such as salbutamol), for
categories of drugs (such as bronchodilators), or for therapeutic areas
(such as respiratory drugs). This information is available at
individual practice level, health authority level, and national level,
allowing different analyses (box 2).
Unit of analysis Level of analysis PACT includes information on prescribing costs, the
number of items prescribed, and generic prescribing. This information
can be looked at using different units of analysis or different levels
of prescribing data. General practitioners will be mainly interested in
their own practice's PACT data and how their prescribing compares with
other practices in their health authority. Health authorities will want
to know how they compare with other health authorities and about the
prescribing of their general practices. The NHS Executive will want to
know about prescribing at national and health authority levels After analysis, the data are fed back to both health authorities and
general practitioners. General practitioners generally only receive a
printed version of the analysis. This information (the standard PACT
report) contains information on the practice's rates and costs of
prescribing along with comparative information. General practitioners
can ask for more detailed information but this more detailed report is
very unwieldy. By contrast, health authorities receive both printed
reports on general practices' prescribing and also have access to
computerised PACT data (PACTLINE). Recently, the PPA has also developed
HEAPACT (health authority electronic PACT). This allows health
authorities' pharmaceutical advisers to obtain information on the
prescribing of specific drugs directly from the PPA via a modem link.
With HEAPACT, health authorities can look at prescribing in great
detail. For example, the prescribing of new classes of drugs such as
selective serotonin reuptake inhibitors can be examined to determine
which general practices are the first to make major use of
them.
Traditionally, PACT has been mainly used as a financial tool to
help health authorities set and monitor general practice prescribing
budgets. However, PACT is now increasingly used for other purposes,
including audit and research, improved methods of funding high cost
drugs, and the development of practice formularies. Because prescribing
is heavily influenced by general practices' demography, weightings for
age and sex have been developed so that rates and costs of prescribing
in different practices or health authorities can be
compared.(3,4)
Budget setting
Health authority budgets
The NHS Executive has recently begun to use PACT data to develop a
formula for allocating prescribing budgets to health
authorities.(5) Variables were used to develop a statistical
model that could be used to explain variations in prescribing costs
between health authorities. Variables that were found to be associated
with prescribing costs included the age and sex weighted population
(measured with ASTRO-PUs), cross boundary flows (patients living in one
health authority but registered with a general practice in another
health authority), and the percentage of people in a health authority
with permanent sickness (obtained from the 1991 census). Health
authorities that were more than 2% below their predicted spending were
given a larger increase in their prescribing budget than other health
authorities. The NHS Executive is now encouraging health authorities to
consider using similar methods when they in turn allocate budgets to
practices.
General practice budgets
PACT data are used by health authorities to help set and
monitor general practices' prescribing budgets. For many years, these
budgets were based on prescribing units, but most health authorities
now use ASTRO-PUs as these provide better weightings for age and sex
than do prescribing units. Because there is no valid capitation based
formula for allocating prescribing budgets to practices, health
authorities have to use their judgment when allocating budgets. In
effect, this means that practices with a good grasp of their past and
current PACT data are likely to be able to argue a better case than
other practices and hence obtain a larger prescribing budget.
Health services research
Prescribing indicators
Markers of good prescribing
Markers of bad prescribing* *Usually measured as number of items per
ASTRO-PU Health authorities currently use many different indicators, but
they are largely unvalidated and an important subject for further
research will be to see if these indicators are valid measures of the
quality of general practitioners' prescribing. Much of the research in
this subject has tried to validate indicators by examining their
association with other process measures. For example, several
researchers have looked at the association between the ratio of inhaled
corticosteroids to inhaled bronchodilators and admission rates for
asthma.(11-13) The next step in this research will be to
v Current NHS information systems make it straightforward for health
authorities to produce a large number of prescribing indicators, and
care is needed in deciding how indicators are selected and used.
Ideally, prescribing indicators should be used to improve the quality
and effectiveness of prescribing in general practice and not simply to
reduce prescribing costs.(14) Furthermore, like all
indicators of performance, prescribing indicators can create perverse
incentives, and it would be fairly straightforward for practices to
improve their performance as measured by many of the indicators without
improving their clinical management of patients.(15) For
example, a practice with a low ratio of inhaled corticosteroids to
inhaled bronchodilators could improve its ratio by indiscriminately
increasing its prescribing of inhaled corticosteroids without improving
other aspects of patient management such as patient education or
adequate record keeping.
Despite their limitations, however, prescribing indicators do
offer potential benefits to general practitioners. For example, general
practitioners can use them to set and monitor their practice's
progress towards a target rate of prescribing generic drugs.
Identifying expensive drugs
This approach has now been adopted by many health authorities. For
example, Kingston and Richmond Health Authority has used PACT data in
combination with notifications from general practices to identify
patients taking any drug costing more than £1500 a year (table 1).
Patients who need a drug that costs more than £2000 a year have the
cost of the drug met from a special health authority budget for
expensive drugs. One byproduct of this is that the health authority has
been able to produce a database of patients who need expensive drugs
including information on diagnosis. This information can then be fed
back to local practices to help them manage their prescribing budgets
and to plan the clinical management of these patients. The register
also has other potential uses: for example, it can be used to identify
patients with specific conditions and hence can be used to identify
samples of patients for audit and research.
At present, it is much easier to identify expensive drugs than to
identify expensive patients, as high cost drugs can be identified
through PACT data. Unfortunately, patients who require multiple low
cost drugs and who therefore have high overall drug costs cannot be
identified through the PACT system. This is because PACT can not yet
provide patient based data.
Analysing prescribing in therapeutic areas
Although PACT data have many uses, they do have some important
limitations, the most important being that the data provide only a
narrow range of information, mainly on what drugs were prescribed and
how much the prescribed drugs cost. Secondly, the data cannot be linked
to demographic or clinical data on patients. Hence, they cannot be used
to calculate age and sex specific prescribing rates or to look at
p Most general practitioners currently receive their PACT data
from the PPA in the form of a booklet. Many health authorities are also
producing prescribing indicators for feedback to their general
practitioners, and in some cases these indicators are distributed in
electronic format. In some areas general practitioners have also been
given access to their entire PACT data in electronic format. The next
step in making PACT data more accessible will be to extend this
initiative and to provide PACT data in electronic format to all
practices that want this. However, to make effective use of electronic
PACT data, general practitioners will need training in how to analyse,
interpret, and use PACT data appropriately. There are two developments that would substantially improve
the usefulness of PACT data. The first would be to include a unique
patient identifier (such as the NHS number) on the prescription. This
would allow prescriptions to be linked to individual patients, leading
to patient based PACT data and the calculation of age and sex specific
prescribing rates. It would also allow general practices and health
authorities to identify patients who have high drug costs and thus lead
to more reliable s The other major development that would improve PACT would be to include
diagnostic data (perhaps in the form of a Read code) on the
prescription. This would allow prescribing for specific clinical
conditions to be analysed. Because many drugs, such as beta
blockers and angiotensin converting enzyme inhibitors, have more than
one indication, PACT data cannot currently be used for this.
Neither of these developments would be easy to implement and,
realistically, would not be feasible until all general practices are
fully computerised and issue virtually all prescriptions with their
practice computers. Including clinical data on the prescription form
would also raise issues about confidentiality, and this might prevent
the implementation of this measure. However, as well as improving the
usefulness of PACT data, these developments, especially the use of a
unique patient identifier, could lead to a lower level of prescription
fraud and thus yield some financial savings.
(Accepted 22 October 1997)
Pontilen, Merton,
Sutton and Wandsworth Health Authority, Kingston & Richmond Health Authority,
Correspondence to: Dr
Majeed
email: a.majeed@sghms.ac.uk
References
1 Audit Commission. A prescription for
improvement: towards more rational prescribing in general
practice. London: HMSO, 1994.
2 Freemantle N, Henry D, Maynard A, Torrance G. Promoting cost
effective prescribing. BMJ 1995;310:955-6.
3 Roberts S J, Harris C M. Age, sex and temporary resident
originated prescribing units (ASTRO-PUs): new weightings for analysing
prescribing of general practices in England. BMJ
1993;307:485-8.
4 Lloyd D C E F, Harris C M, Roberts D J. Specific therapeutic
age-sex related prescribing units (STAR-PUs): weightings for analysing
general practices' prescribing in England. BMJ
1995;311:991-4.
5 Reeves C L. Prescribing expenditure: guidance on
allocations and budget setting for 1997/98. NHS Executive:
Leeds, 1996. (EL(96)107.)
6 Morton-Jones T, Pringle M. Explaining variations in
prescribing costs across England. BMJ
1993;306:1731-4.
7 Wilson R P H, Hatcher J, Barton S, Walley T. Influences of
practice cha
8 Harris C M, Scrivener G. Fundholders' prescribing costs: the
first five years. BMJ 1996;313:1531-4.
9 Griffiths C, Sturdy P, Naish J, Omar R, Dolan S, Feder G.
Hospital admissions for asthma in east London: associations with
characteristics of local general practices, prescribing and population.
BMJ 1997;314:1482-6.
10 Bateman D N, Eccles M, Campbell M, Soutter J, Roberts S J, Smith
J M. Setting standards of prescribing performance in primary care: use
of a consensus group of general practitioners and application of
standards to practices in the north of England. Br J Gen
Pract 1996;40:20-5.
11 Shelley M, Croft P, Chapman S, Pantin C. Is the ratio of
inhaled corticosteroid to bronchodilator a good indicator of the
quality of asthma prescribing? Cross sectional study linking
prescribing data to data on admissions. BMJ
1996;313:1124-6.
12 Aveyard P. Assessing the performance of general practices
caring for patients with asthma. Br J Gen Pract
1997;420:423-6.
13 Griffiths C, Naish J, Sturdy P, Pereira F. Prescribing and
hospital admissions for asthma in east London. BMJ
1996;312:481-2.
14 Baker S J. Use of performance indicators for general practice.
BMJ 1996;312:58.
15 Majeed F A, Voss S. Performance indicators for general practice.
BMJ 1995;311:209-10.
16 Heath I. The creeping privatisation of NHS prescribing.
BMJ 1994;309:623-4.
17 Bogle S M, Harris C M. Measuring prescribing: the shortcomings of
the item. BMJ 1994;308:637-40.
Box 1: Definitions of key terms What information is available
Box 2: Units of analysis and levels of PACT data
1 England
2 Health authority
3 General practice
1 Total prescribing, prescribing by British National
Formulary chapters
2 Prescribing by subsections of British National
Formulary chapters
3 Prescribing of individual drugs How is PACT used
PACT data have been widely used by researchers to investigate
variations and trends in prescribing costs.(6) For example,
studies that have examined differences in prescribing costs between
fundholding and non-fundholding practices have generally used PACT
data.(7,8) Studies of the management of conditions such as
asthma, comparing admission rates with prescribing rates, have also
generally used PACT data.(9)
A relatively new development is to use PACT data to develop
prescribing indicators. Many health authorities now do this, often in
consultation with general practitioners, and a large number of
indicators have been developed (box 3).(10) The assumption
is that these indicators can be used to measure the quality or
prescribing in general practice. Some indicators, such as the ratio of
inhaled corticosteroids to inhaled bronchodilators, are considered to
measure good prescribing while other indicators such as the rate of
prescribing of appetite suppressants are considered to measure bad
prescribing.
Box 3: Prescribing indicators commonly used by health
authorities
Rate of generic prescribing Frusemide and bendrofluazide as a percentage of
diuretic drugs Ratio of bendrofluazide 2.5 mg to bendrofluazide
5 mg Atenolol and propranolol as a percentage of beta
blockers Ratio of inhaled corticosteroids and cromoglycate to
inhaled bronchodilators Cimetidine as a percentage of H2 receptor
antagonists Generic antibiotics as a percentage of all
antibiotics
Diuretic potassium combinations Cerebral and peripheral vasodilators Appetite suppressant Topical non-steroidal anti-inflammatory drugs Benzodiazepines Cough mixtures and decongestants
Patients who need expensive drugs can substantially increase a
practice's prescribing costs. Some general practitioners may therefore
be concerned that having too many patients who need expensive drugs on
their list will prevent their practice from remaining within its
prescribing budget. With PACT data, however, it is possible to separate
the costs of expensive drugs from other prescribing costs. This
information can then be used to adjust general practices' prescribing
budgets to take into account the cost of these drugs.
Table 1 - Annual cost of expensive drugs (drugs costing
more than £1500 a year) in one general practice in Kingston and
Richmond Health Authority
Patient
Diagnosis
Drugs
Annual cost (£)
A Asthma Budesonide 1,628
B Cystic fibrosis Aztreonam
Dornase
alfa2,255
7,442 C Growth hormone
deficiency Somatropin 16,688 D Growth hormone
deficiency Somatropin 13,350 E Growth hormone
deficiency Somatropin 11,140 F Renal
transplant Cyclosporin 4,602 G Renal
transplant Cyclosporin 4,686 H Prostate
cancer Bicalutamide
Goserelin1,668
1,590
I Prostate cancer Goserelin 1,590 J Prostate
cancer Goserelin 1,590 K Prostate
cancer Goserelin 1,590 L Prostate
cancer Leuprorelin 1,630 The practice has a list size of 8,800 patients (33,000
ASTRO-PUs). The total annual prescribing budget for the practice is
£537,227, of which drugs costing more than £1,500 cost £71,449. Six
patients in the practice are taking drugs that cost more than £2,000 a
year. The prescribing costs of these drugs (£60,163, 11.2% of the
practice's total prescribing budget) are reimbursed separately from
the rest of the practice's prescribing costs. Similar data are
available for all 61 practices in Kingston and Richmond Health
Authority. A preliminary analysis of this data has revealed the
increasing number of patients with prostate cancer who are being
treated with hormone therapy.
The recent development of HEAPACT (health authority
electronic PACT) allows health authority medical and pharmaceutical
advisers to download from the PPA detailed information on the
prescribing of general practices. Through HEAPACT, information is
available on the prescribing of individual drugs. This offers both
health authorities and general practitioners a number of opportunities.
For example, it is possible to examine prescribing in specific
therapeutic areas in order to develop practice formularies, rationalise
prescribing, and cut prescribing costs (table 2). HEAPACT also allows
the identification of practices that are prescribing new, expensive
drugs that cost more than older drugs of similar efficacy or drugs that
are known to be ineffective. Although some practices now have access to
and are using data derived from HEAPACT, many practices are not aware
of this development or of the benefits it could offer their practices
(see box 4).Table 2 - Example of the use of HEAPACT data to analyse
prescribing of a class of drugs in a general practice*
Drug
No of items
Cost per item (£)
Total cost (£)
Fluoxetine 144 25.97 3,740
Paroxetine 112 28.42 3,183
Sertraline 100 47.87 4,787
Venlafaxine 43 32.30 1,389
Nefazodone 15 18.20 273
Fluvoxamine 7 13.29 93 Citalopram 5 27.60 138
Total 426 31.93 13,603 *Number of prescriptions of selective serotonin reuptake
inhibitors and related antidepressants (British National
Formulary section 4.3.3) for one practice (list size 5,600) in
Merton, Sutton, and Wandsworth during 1996. The practice prescribed all
seven drugs in this category, with a total cost of £13,603. Three
drugs (nefazodone, fluvoxamine, and citalopram) were prescribed
relatively infrequently, and one drug (sertraline) cost substantially
more than the others. The data suggest that the doctors in the practice
should discuss whether they need to use all the drugs in British
National Formulary section 4.3.3 and whether savings could be
made by reducing the prescribing of sertraline. In the same period the
practice prescribed tricyclic and related antidepressants
(British National Formulary sections 4.3.1 and 4.3.2)
747 times at a total cost of £2,960 (average cost per item £3.96).
Hence, some discussion is also required on what the balance of
prescribing should be between the newer antidepressants and the older
(and substantially cheaper) tricyclic and related antidepressants. Box 4: Potential uses of level 3 PACT data to general
practitioners Provide baseline data on prescribing to help in
preparation of a practice formulary Determine what percentage of drugs prescribed are in
the practice formulary Monitor progress towards prescribing targets Identify areas in which practice prescribing differs
greatly from health authority average Identify therapeutic areas in which greater use of
generic drugs is possible Identify areas where there is scope for therapeutic
substitution - for example, using frusemide and bendrofluazide in place
of more expensive diuretics Identify prescribing of drugs of limited therapeutic
value such as cough mixtures and decongestants Help standardise the quantity of drugs prescribed - for
example, for 28 days versus 30 days Allow calculation of defined daily doses instead of
the number of items as a measure of the amount of a drug
prescribed Limitations of PACT
Making PACT more accessible
Improving PACT
Division
of General Practice and Primary Care,
St George's Hospital
Medical School,
London SW17 0RE
Azeem Majeed,
senior lecturer in general practice
Wilson Hospital,
London CR4
4TP
Norman Evans, pharmaceutical
adviser
22
Hollyfield Road,
Surbiton KT5 9AL
Paula Head,
head of pharmacy
Home | Current contents | Past issues |
Classified ads | Career Focus | Feedback
Collections |
About this site | About the BMJ | BMA | Medline