Access to cardiac catheterisation Influenced by deprivation, not sex
BMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6925.410 (Published 05 February 1994) Cite this as: BMJ 1994;308:410
- N Findlay,
- D Cunningham,
- H J Dargie
EDITOR, - F Kee and colleagues have added to the continuing controversy regarding fair access to cardiological services.1 They found that the rate of cardiac catheterisation was significantly lower in women than men and noted no influence of social background. This is in contrast to our findings.2 We have updated our results and continue to find a strong influence of social deprivation on the uptake of both cardiac catheterisation and coronary bypass surgery, particularly in women (submitted for publication), but no significant sex bias in cardiac catheterisation based on patients discharged from hospital with coronary heart disease.
The following may explain the differing findings. We restricted our analysis to patients aged 35-64 since we thought that they were most likely to be affected by non-clinical variables: younger patients would almost certainly be investigated, irrespective of their social status, and older patients would be presented for investigation because of symptoms that could not reasonably be ignored on demographic grounds. The rates of cardiac catheterisation in our population were roughly four times higher than those in the population studied by Kee and colleagues. Our patients were allocated to eight groups according to their deprivation score; the groups were not equal in size but had comparable mixes of deprivation and affluence. In contrast, Kee and colleagues' patients were divided into fifths. The larger numbers of investigations and social groups in our study may have enhanced our ability to detect an influence of social deprivation. Furthermore, our higher rates of catheterisation may have allowed more liberal and subjective criteria to influence the decision to investigate.
These differences reinforce concerns about different patterns of investigation and treatment of patients with coronary heart disease.3, 4
Access to surgery linked to social class
- R W Morris,
- M Walker,
- A K McCallum,
- P H Whincup,
- S Ebrahim
EDITOR, - F Kee and colleagues report the variation in rates of cardiac catheterisation among electoral wards in Northern Ireland and suggest that social deprivation has little influence on the rate once a proxy measure of clinical need has been taken into account.1 We examined the relation between social class and rates of coronary artery bypass grafting in 7735 men aged 40-59 at entry to the British regional heart study, a prospective investigation of cardiovascular disease in 24 towns in England, Wales, and Scotland. Information on social class was based on occupation at entry to the study in 1978-80. Details of coronary artery bypass operations, and major ischaemic heart disease events were obtained by annual review of the patients' records supplemented by tagging for fatal events at the NHS central register.2
By 1992, 91 men in the original cohort were reported to have undergone coronary artery bypass grafting. Forty (1.31%) of the men with a non-manual occupation had undergone such grafting compared with 48 (1.08%) with a manual occupation (odds ratio (non-manual:manual) 1.21 (95% confidence interval 0.78 to 1.89)). The higher rate of coronary artery bypass grafting in the non-manual group contrasts with the lower proportion of men in this group who had either evidence of ischaemic heart disease at entry to the study (odds ratio 0.65 (0.57 to 0.75)) or a major fatal or non-fatal ischaemic heart disease event during follow up (odds ratio 0.74 (0.61 to 0.88)).
These results suggest that social class differences in rates of coronary artery bypass grafting may not reflect clinical need, at least in this study population. The extent to which the imbalance observed reflects differences in rates of cardiac catheterisation and social class differences in acceptance rates for operation, possibly influenced by smoking1 and other clinical and social factors, requires further exploration.