PR OGNO S I S
Socio-economic deprivation is associated with increased early recurrent ischaemic events following admission for acute myocardial infarction Abstracted from: Barakat K, Stevenson S, Wilkinson P, Suliman A, Ranjadayalan K, Timmis AD. Socioeconomic differentials in recurrent ischaemia and mortality after acute myocardial infarction. Heart 2001;85:390}394
BACKGROUND Socio-economic deprivation increases the risk of coronary events and mortality but there is limited information available on a case by case basis.
SETTING One London hospital; January 1988}December 1996.
MAIN RESULTS There was no association between deprivation score and age, sex, smoking status or clinical treatment. Those from deprived districts were more likely to be South Asian, diabetic and develop Q-wave infarction and left ventricular failure. They were also at greater risk of death, recurrent myocardial infarction, and unstable angina in the first 30 days. Socio-economic deprivation was not associated with altered 1-year survival rates.
PARTICIPANTS One thousand four hundred and seventeen South Asian and white people admitted to hospital with acute myocardial infarction; age 52}73 (mean 63); three-quarters male.
AUTHORS’ CONCLUSIONS There is a strong relationship between socio-economic deprivation and early recurrent ischaemic events. This does not last over time.
INTERVENTION Participants were classified using the Carstairs socio-economic deprivation score based on residential district. This is a composite of census data about household-head social class; overcrowding; car ownership; and unemployment. Data of 1991 was used.
NOTES The use of postcodes to define socio-economic status; the possibility of unconsidered confounders; and selection bias (people who reach hospital may be less likely to be deprived) should be considered when interpreting the results.
OBJECTIVE To examine the relationship between socio-economic deprivation and case fatality following acute myocardial infarction. DESIGN Prospective 9-year cohort study.
Commentary It is well known that groups with low socio-economic status have high acute myocardial infarction mortality rates. This inequality can in part be attributed to the social patterning of acute myocardial infarction incidence rates. Similarly, the proportion of acute myocardial infarction patients reaching the hospital alive is associated with socio-economic status. It is less clear if socio-economic differences in case-fatality among hospitalised patients contribute to the explanation of the inequality in acute myocardial infarction mortality. In recent European studies, pre-hospital acute myocardial infarction death rates were markedly associated with social or occupational class, whereas little or no evidence of differences in case-fatality after hospitalisation was found.1,2 In contrast, in the USA, survival 90
OUTCOMES Thirty day and 1-year survival following admission for acute myocardial infarction.
Evidence-based Cardiovascular Medicine (2001) 5, 90d91 doi:10.1054/ebcm.2001.0376, available online at http://www.idealibrary.com on
among hospitalised acute myocardial infarction patients has been shown to be worse in groups with low education.3 In this well-conducted study of hospitalised acute myocardial infarction patients, recurrent ischaemia and case-fatality rates were shown to differ between socio-economic groups (classified by an area-based deprivation score), at 30-day follow-up but not at 1-year follow-up. Accounting for several prognostic factors did not explain the observed differences. The observed inequality is noteworthy as the study population was restricted to a rather homogenous area, with a limited range of socio-economic status. Inequalities in mortality and recurrent events in hospitalised patients could reflect differences regarding initial severity of the disease, access to care and quality of care, and time delay from first symptoms to care between the socio-economic groups. In the present study, some information on these factors is given and ^ 2001 Harcourt Publishers Ltd
properly accounted for, thus leaving the observed differences largely unexplained. This research demonstrates that further studies on socio-economic differentials in hospitalised acute myocardial infarction patients are needed. Still, from a public health point of view, inequalities after hospitalisation are likely to have a minor role in explaining the distinct social pattern in total acute myocardial infarction mortality, as the majority of deaths occur before reaching the hospital.4 Markku Peltonen, PhD Institute of Internal Medicine, Sahlgrenska University Hospital, Sweden Literature cited 1. Morrison C, Woodward M, et al. Effect of socioeconomic group on incidence of, management of, and survival
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after myocardial infarction and coronary death: analysis of community coronary event register. BMJ 1997; 314: 541}546 2. Lang T, Ducimeriere P, et al. Is hospital care involved in inequalities in coronary heart disease mortality? Results from the French WHO-MONICA Project in men aged 30}64. J Epidemiol Community Health 1998; 52: 665}671 3. Tofler GH, Muller JE, et al. Comparison of long-term outcome after acute myocardial infarction in patients never graduated from high school with that in more educated patients. Multicenter Investigation of the Limitation of Infarct Size (MILIS). Am J Cardiol 1993; 71: 1031-1035 4. Chambless L, Keil U, et al. Population versus clinical view of case fatality from acute coronary heart disease: results from the WHO MONICA Project 1985}1990. Multinational MONItoring of Trends and Determinants in CArdiovascular Disease. Circulation 1997; 96: 3849}3859
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