Annex A
ESTIMATES OF SPECIALIST ALLERGY CLINIC CAPACITY
AND POPULATION NEED
SUMMARY
1. The numbers of children with allergy
in need of specialist help are estimated to be increasing by over
40,000 each year across the UK. An estimated minimum of 2.7 million
people currently need specialist diagnosis and treatment for their
allergy. NHS allergy clinics are able to cope with a maximum of
50,000 new cases a year—less than 2% of estimated unmet
need, assuming no annual increase in need. All current clinics,
working as they are, would take over 50 years to clear the backlog,
if there were to be no new cases of severe or complex allergy.
APPROACH
2. We thought it useful to form estimates
of allergy clinic capacity in relation to estimated population
need.
3. In the time and with the data available
the estimating process is inevitably imprecise. Estimates are
provided for the UK taken as whole.
4. In the calculations below an indication
is given, at each step, as to whether an aggregate under or over
estimate is likely to result.
CLINIC CAPACITY
5. Clinics
The BSACI data base of NHS allergy clinics,
published on the BSACI website (bsaci.org) was used for the estimate.
Other clinics in the country may offer an allergy service. True
capacity may therefore be somewhat higher than these estimates.
But we have no reliable data on the additional services on offer.
And it was judged that the BSACI members' clinics comprise the
core of the current national, evidence based allergy service.
6. Doctor Sessions
The numbers of self defined, half day doctor
sessions available for each clinic in the data base were used
as the measure of clinical capacity. These show:
(a) Dedicated clinics led by an allergy
specialist have 123.5 half day sessions available per week.
(b) Other clinics offer 184.5 half day allergy
sessions (since patients with other illnesses may also be treated
in these clinics, this may be an over estimate of true capacity).
Most do not offer a comprehensive service. These clinics are run
by consultants in other specialties.
(c) Total tertiary and secondary care for
allergy is therefore estimated at 308 half day doctor sessions
a week.
7. New Patients per session
It was assumed that a doctor might diagnose
and treat four new and four repeat cases at each clinic session.
This is a broad approximation; the true figure will vary with
the case mix being managed in the clinic. Many clinics are trying
to see patients only once (increasing throughput); this means
that they see patients only once, but for longer.
8. The working year
The Royal College of Physicians working year
protocol for manpower forecasting was used—a 42 week clinic
year. On this basis the existing clinics can diagnose and treat
new cases as follows:
(a) Specialist clinics (123.5 x 4 x 42) =
c 20,748 patients a year
(b) Other clinics (184.5 x 4 x 42) =
c 30,996 patients a year
(c) Total capacity (308 x 4 x 42) =
c 51,744 new cases a year.
9. Numbers already treated
In order to form an estimate how many people
who require specialist help may already have received it, we assumed
that all current clinics offering an allergy service have operated
for the last five years and have discounted from the equation
the number of new cases they might be assumed to have treated.
(This could result in either under or over estimates. Clinics
have closed over the period; and the number of doctors working
in the existing clinics have increased. On balance, given the
need to decide a broad estimate based on the most robust available
data, we have assumed equivalent capacity exists over the five
year period.)
10. The results indicate that, of the need
estimate—see paragraphs 11 to 15 below—(51,744 x 5)
= 260,000 of the people needing specialist help may already have
received it.
POPULATION NEED
11. The allergy population estimates published
in Allergy : the Unmet Need were principally used for this.
12. Aggregate need
30% of the total population (18 million UK;
and 15 million in England) have allergy. 40% of children have
allergy
13. Specialist care for adults
One in six people of those who have allergy
are estimated to have sufficiently severe symptoms to require
tertiary level, specialist help—three million people. It
was recognised by the Royal College that a further group of patients
required more specialist care than could be provided in primary
care; but no estimates could be made of the size of this additional
population.
14. Outstanding potential case load
The total of outstanding allergy cases in need
of specialist help is in consequence estimated at a minimum of
(3,000,000—260,000) = a minimum of 2,740,000 across the
UK.
15. Specialist care for children—new
cases each year
With a UK current birth cohort of 650,000 and
using the same assumption as in the paragraphs above for children,
an estimated minimum of 43,000 new cases of paediatric allergy
requiring specialist advice can be expected to present each year.
This discounts all new cases of adult onset allergy.
NEEDS AND
CURRENT CAPACITY
16. Conclusion
Estimation with the information available can
give at best order of magnitude results. As services develop,
more robust data must be created to support service planning.
Taken as a whole the results show:
— An estimated minimum of 2,740,000 people
need specialist help with their allergy. They have not received
it.
— The available specialist allergy clinics
are able to diagnose and treat 20,748 patients a year—around
0.8% of estimated current need.
— All clinics offering some type of allergy
service, with any capacity to diagnose and treat allergy above
primary care level, are able to manage 51,744 patients a year—less
than 2.0% of estimated current need.
— To put this another way. All current
clinics, working as they are, would take more than 50 years to
clear the allergy backlog, if nothing changed.
— To put this another way again. Concentrating
growth in service capacity into the development of a specialist
allergy service within the NHS (as recommended by the Royal College)
would still need to be supported by other clinical services. But
pressure on these services would be relieved. Assuming a 10 year
clear up rate for the estimated needs backlog, and also assuming
no new need emerging, the other clinics would be able to contribute
10-12% of clinic care over the period, working as they are.
— An estimated minimum of 43,000 new cases
of paediatric allergy in need of specialist help are occurring
year on year.
— Therefore, new severe, paediatric allergy
need requiring specialist advice, year on year, is estimated to
be more than twice the size of the capacity of current specialist
allergy clinics (adult and paediatric taken together); and 80%
of total clinic capacity.
These estimates take no account of
imbalances which exist in primary care. Insufficient data exists
to make any such estimates.
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