What is most crucial about this news is that it marks the first time in many years that the rates of heart attacks have increased, as they have been steadily declining.
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Official: Scotland sees large rise in hospital admissions for acute coronary syndrome in second year of smoking ban
Data released this week by the Scottish government show that emergency
hospital admissions for acute coronary syndrome (ACS) rose sharply in
the second year of the country's smoking ban.
Much
was made of an apparent reduction in the number of patients being
diagnosed with the life-threatening heart condition after the smoking
ban came into effect in 2006, including a study published in the New England Journal of Medicine which claimed that the ban had caused emergency ACS admissions to fall by 17%.
However, official statistics show that the decline in hospitals
admissions for acute coronary syndrome has been greatly exaggerated.
The real decline in the first year of the smoking ban was just 7.2% -
not 17% - and the rate then rose by 7.8% in the second year, cancelling out the earlier drop.
In the last 12 months before Scotland enacted its smoking ban (April 05
to March 06) there were 16,199 admissions for acute coronary syndrome*.
In the second year of the smoking ban (April 07 to March 08) there were
16,212 admissions, slightly more than there had been before the
legislation was enacted.
Hospitalisations for acute coronary syndrome in the last 10 years.
Source: ISD Scotland
Hospital admissions for acute coronary syndrome
have been declining in Scotland for many years. The new data show that
the well-publicised fall in admissions following Scotland's smoke-free
legislation was in line with the existing downward trend and was
significantly less steep than has previously been claimed.
The belief that the number of cases of acute coronary syndrome fell by
17% after the smoking ban stems from a study of volunteers in a
selection of Scottish hospitals between 2005 and 2007. The study -
'Smoke-free Legislation and Hospitalizations for Acute Coronary
Syndrome' - has since been criticised for its limited scope and for
excluding data from several key months before and after the ban.
If the 2006-07 decline had really been the result of the smoke-free
legislation, it would be expected for rates to remain low in subsequent
years. The fact that Scottish hospitals have seen an unusually sharp rise
- despite the smoking ban being rigorously enforced - suggests that
whatever lay behind the 2006-07 dip, it was not the smoking ban.
Hospital data from England and Wales has failed to show a significant
reduction in incidence of acute coronary syndrome since going
smoke-free in 2007.
This new evidence from Scotland casts serious doubts on the theory that
smoking bans have a measureable impact on incidence of acute coronary
syndrome.
Christopher J. Snowdon is the author of Velvet Glove, Iron Fist: A History of Anti-Smoking
* The World Health Organisation defines Acute Coronary Syndrome as
being acute myocardial infarction (AMI) (ICD-10 code I21-22) and angina
(ICD-10 code I20).
17.02.06: STOPIT (STudy Of Public place Intervention on Tobacco exposure) announce the decision to conduct a study designed to "test the hypothesis raised by the Montana study
that a reduction in ETS [Environmental Tobacco Exposure] exposure is
accompanied by a rapid reduction in the incidence of acute coronary
syndrome (ACS)." The study is to be led by Dr Jill Pell.
10.9.07:
Dr Pell and her team announce their findings at a conference in
Edinburgh. The Scottish government marks the occasion by issuing a
press release titled 'Smoking ban brings positive results'
saying: "A study of nine Scottish hospitals has found a 17 per cent
fall in admissions for heart attacks in the first year after the
smoking ban came into force."
11.9.07:
International media, including The Times, The Guardian and The Daily Mail report the news that, as the latter put it:
"Further dramatic evidence emerged last night to show that banning smoking in public reduces the rate of heart attacks.
Hospital admissions for heart attacks dropped by 17 per cent in the year after the legislation was introduced in Scotland.
If the pattern is repeated throughout the UK, there would be almost 40,000 fewer heart attacks a year."
14.11.07:
The BBC publish an article (online) titled 'When the facts get in the way of a good story'.
The author noted that data from ISD Scotland showed that the real drop
in heart attacks was just 8%. He added: "What appeared to be hard
medical evidence now looks more like over-hasty and over-confident
research, coupled with wishful political thinking and uncritical
journalism."
22.12.07:
The Times includes the study in its list of 'The worst junk stats of 2007'.
30.7.08:
On the eve of the study's publication, the international media report the findings again. USA Today
writes: "Scotland's smoking ban appears to have prevented hundreds of
heart attacks in its first year, a study shows.
The number of people admitted to the hospital for heart attacks fell by
17% in the year after Scotland's smoking ban took effect in March 2006."
Tom Glynn of the American Cancer Society calls the study "virtually flawless'.
31.7.08:
The study is finally published in the respected New England Journal of Medicine titled 'Smoke-free Legislation and Hospitalizations for Acute Coronary Syndrome'.
19.09.08:
Velvet Glove author obtains additional hospital data under the Freedom of Information Act. Provisional data suggests that acute coronary syndrome admissions fell by 9.3% in the 12 months following the ban.
25.11.08:
Scottish government quietly releases final figures
for hospital admissions since the smoke-free legislation. Acute
coronary syndrome admissions fell by just 7.2% in year one - in line
with the long-term downward trend - before rising by 7.8% in year two.