Given that the majority of CHF patients are managed within the community,11 the focus on SES and hospitalized CHF patients in all the reported clinical trials may indicate a relationship between SES and CHF; however, this may not be generalizable to the majority of CHF patients.
Much remains unclear about the influence of socioeconomic status on CHF. Linking this review with the wider SES and chronic disease literature indicates a number of ways in which socioeconomic deprivation may contribute to excess mortality in CHF and inequalities in health care. Six issues merit particular investigation.
Health care provider inequalities
There is some evidence that SES may influence individual health care providers’ clinical management of CHF. Struthers and colleagues10 demonstrated an increased rate of re-hospitalization in those with lower SES that was independent of disease severity. Given that the subsequent length of stay was not influenced by social deprivation, the researchers suggested that an explanation of the re-admission rates purely in terms of co-morbidity and poor social support is flawed. Alternative explanations could include:
Primary care providers dealing with CHF in deprived areas have less time for intensive management within the community.
Primary care providers working in deprived areas may perceive that their patients have less capacity to understand and manage their own condition.
Patients within a deprived area may perceive that community medical resources are insufficient to manage them safely at home and “push” for admission.
These hypotheses are unproven, but merit investigation; they could potentially influence the day-to-day management of patients with CHF.
Risk factor inequalities
Half of the excess coronary mortality in the socially deprived may be attributed to uncorrected risk factors such as smoking.10 The risk factor pattern for CHF is similar to coronary heart disease38 and includes clearly identified etiologies, such as hypertension, coronary artery disease, diabetes mellitus, valvular heart disease, and cardiomyopathies.11,19
Several of these factors have a well–documented SES bias.39,40 Consequently, it seems plausible to assume that a proportion of the excess mortality in CHF in lower socioeconomic groups will be because of these SES-driven risk factors, but no definitive evidence for this exists.
Nonconcordance is viewed as contributory factor in a large number of CHF admissions.41,42 Nonconcordance has been at times assumed to be greater in the socially deprived and may contribute to morbidity. However, Struthers and colleagues10 found that at least regarding the impact of SES and acute admissions, nonconcordance with diuretics was independent of the association demonstrated.
The prescription of angiotensin-converting enzyme inhibitors for CHF is demonstrably lower in elderly patients admitted with this condition.43 If there is a significant age bias regarding the prescription of drugs of specific benefit in CHF44 it may well be that a SES bias also exists, reflecting a perpetuation of the inverse care law.45 Further exploration of this subject is needed.
An age-related bias in follow-up for patients admitted with CHF to a geriatric ward has been demonstrated, with more receiving follow-up by primary care rather than cardiology outpatients, compared with younger patients admitted to medical wards.44,46 A similar association may exist regarding SES and might partly explain the excess mortality in this group. A SES bias has been demonstrated in studies looking at re-vascularization rates for angina.47,48 Socioeconomically deprived patients with coronary heart disease are less likely to be investigated or offered surgery despite their increased risk.49 Only 2 CHF studies are directly comparable.34,36 The former looked at barriers to cardiac transplantation in end-stage CHF caused by idiopathic dilated cardiomyopathy. The latter examined factors associated with obtaining cardiologist care among patients with acute exacerbation of CHF.
In an acute situation, those from lower SES groups may access care differently from their more affluent peers. This has been demonstrated in asthma admissions where such patient groups are more likely to visit an emergency department than their primary care provider.50 Other studies considering emergency admissions across all diseases23,51 demonstrated that those with a lower SES had an increased probability of being admitted via the emergency department. If the same effect is replicated for CHF, as seems probable, this could result in significant differences in the long-term management of these groups. Patients who primarily access emergency physicians when unwell will, by implication, be less exposed and responsive to long-term disease monitoring in primary care.
There is an independent association between social deprivation and the prevalence of neurotic and psychiatric conditions.52 Thus, individuals and families with low incomes may have a reduced ability to cope with stressful events.53 This could influence patient behavior in sufferers of CHF, perhaps explaining the readmission rates because of a reduced capacity in the individual to cope mentally with the illness. Further exploration of this variable in initial presentation and subsequent management is required.