Caroline A Daly, Bianca De Stavola, Jose L Lopez Sendon, Luigi Tavazzi, Eric Boersma, Felicity Clemens et al
Daly C A, De Stavola B, Sendon J L L, Tavazzi L, Boersma E, Clemens F et al.
Predicting prognosis in stable angina—results from the Euro heart survey of stable angina: prospective observational study
BMJ 2006; 332 :262
doi:10.1136/bmj.38695.605440.AE
Prognosis estimates need to be for all patients with angina
I welcome Daly’s work addressing the neglected area of the
contemporary prognosis of angina. (1) However I believe there is an
important flaw in the study. The authors state that they aimed “to study
a representative population with stable angina, not just pre-selected
patients admitted to hospital” and yet they then state that they recruited
patients on “new presentation to a cardiologist as an out patient”. (2)
I believe that there will be an important selection bias between
people with angina in primary and secondary care. Historically few
patients with angina have been referred from primary care (3) This may be
changing at least in the UK with the new UK GP contract (4) Data arising
from the Quality and Outcome framework (QOF) monitoring system (5) of the
new GP contract would suggest there is still a large pool of patients with
angina in the community, as it indicates a coronary heart disease
prevalence of 3.6% (1,893,184) of the population of England. Previous
work (6) has suggested that approximately 50% of those labelled with CHD
in primary care will have angina, suggesting approximately 900,000
sufferers with angina in England. QOF data also reports there were
174,000 incident cases of angina in England (over the 2 year window) which
gives a new incidence rate of angina of 0.33% (0.17% pa). (7) There are
problems with these data, but the consistency of prevalence across primary
care trusts suggests these figures are of value.
This new data would suggest with respect to angina, that there is a
considerable clinical iceberg. Most patients experiencing angina are not
visible from the perspective of a cardiology out patients. It is also
recognised that some people with angina like symptoms do not consult at
all. (8) I believe therefore that any prognostic scores based on this
hospital based population, while useful, should be treated with caution.
Prognosis of angina can only ever be estimated if a representative
population of sufferers are studied.
Melvyn Jones
Senior Lecturer in General Practice
Royal Free & University College London Medical School
m.jones@pcps.ucl.ac.uk
Reference List
(1)Daly CA, De Stavola B, Sendon JLL, Tavazzi L, Boersma E, Clemens F
et al. Predicting prognosis in stable angina--results from the Euro heart
survey of stable angina: prospective observational study. BMJ 2006;
332(7536):262-267.
(2)Daly CA, Clemens F, Sendon JLL, Tavazzi L, Boersma E, Danchin N et
al. The clinical characteristics and investigations planned in patients
with stable angina presenting to cardiologists in Europe: from the Euro
Heart Survey of Stable Angina. European Heart Journal 2005; 26(10):996-
1010.
(3)Clarke KW, Gray D, Hampton JR. Implication of prescriptions for
nitrates: 7 year follow up of patients treated for angina in general
practice. Br Heart J 1994; 71(1):38-40.
(4)New GMS contract. 2003. BMA / NHS Confederation.
Ref Type: Generic
(5) Lester H, Sharp D, Hobbs FDR, Lakhani M. The quality and outcomes
framework of the GMS contract: a quiet evolution for 2006. Br J Gen Pract
2006; 56(525):244-246.
(6)Campbell NC, Ritchie LD, Thain J, Deans HG, Rawles JM, Squair JL.
Secondary prevention in coronary heart disease: a randomised trial of
nurse led clinics in primary care. Heart 1998; 80:447-452.
(7) The Health and Social Care Information Centre (NHS). Quality and
Outcomes Framework (QOF) for April 2004 - March 2005, England
http://www.icservices.nhs.uk/qofdocuments/QOF0405_SHAs_Prevalence.xls .
2006.
(8)Owen Smith V, Hannaford PC, Elliot AM. Increased mortality among
women with Rose angina who have not presented with ischaemic heart
disease. British Journal of General Practice 2003; 53:784-789.
Competing interests:
I am researching prognosis in primary care settings
Competing interests: No competing interests