ABSTRACT
OBJECTIVE: To examine and assess the available literature concerning the effects of socioeconomic status (SES) and congestive heart failure (CHF).
STUDY DESIGN: We examined electronic databases, including: MEDLINE, EMBASE, Social Science Citation Index, Science citation index, the Cochrane Database, and Bandolier. We hand searched recent copies of appropriate journals and scrutinized lists of identified papers. The search terms we used included “heart failure,” “cardiac failure,” “ventricular dysfunction,” “social class,” “socioeconomic,” “poverty,” and “deprivation.” Two reviewers independently examined and selected papers for inclusion. A standardized data collection form was used for data extraction.
OUTCOMES MEASURED: We measured (1) prevalence; (2) differences in care (eg, use of diagnostic tests); (3) morbidity (eg, health care use); and (4) mortality.
DATA SOURCES: We examined all English-language abstracts or papers concerning human research related to the subject of SES and CHF, including all clinical trials, reviews, discussion papers, and editorials.
RESULTS: Only 8 clinical studies were identified that specifically examined aspects of the relationship between socioeconomic status and CHF. Key themes included increased hospitalization rates with increasing social deprivation; lower income inversely associated with being placed on a waiting list for transplantation; and that those of lower socioeconomic status had a greater severity of illness on admission.
CONCLUSIONS: There is a paucity of generalizable high-quality research in this subject area. Crucial issues not addressed include the effects, if any, of socioeconomic status on the behaviors of health care providers. Further investigation, with a more holistic approach, is necessary to inform future intervention strategies aimed at reducing excess mortality from CHF.
Congestive heart failure (CHF) is a significant health problem resulting in spiraling health care costs in the United States. The annual cost of inpatient treatment for CHF was close to $8.9 billion in 19851; in 1991, it was estimated to generate 2.3 million hospital stays and 11 million outpatient visits that resulted in an annual cost of more than $38 billion. This represents an estimated 5% of the total national expenditure for health care in the United States.2 Current statistics indicate that 4.9 million US citizens are afflicted with this syndrome,3 and the impact on the individual patient cannot be underestimated with its approximate 60%, 5-year mortality rate.4
Social deprivation is associated with an increased burden of disease5 and with health inequalities.68 The link between socioeconomic inequalities and cardiovascular disease mortality is well-documented and forms a major public health problem in industrialized countries.9 However, much less is understood about the impact of socioeconomic status, specifically on CHF. Even if the risk-factor pattern for CHF is similar to that of coronary artery disease (CAD), a recent study has suggested that only one half of excess coronary mortality in the socially deprived is attributed to such uncorrected risk factors as smoking.10 Thus, at least 50% of the excess mortality associated with lower socioeconomic status in heart failure may not be explained by such comparisons. This figure may be even greater as CHF is secondary to CAD in less than 50% of cases.11
The prevalence of CHF and mortality from the disease are reportedly higher in those with a lower socioeconomic status (SES).12 However, little evidence exists to explain this observation. A greater comprehension of the influence of socioeconomic variables is crucial when developing effective and equitable primary prevention, detection, and treatment strategies for this major public health problem. In this study, we examined the existing evidence spotlighting SES and CHF and potential relevant inequalities in health care use or provision. In particular, we have focused on variables that have the potential to contribute to an SES bias and highlight priorities for future investigation.
Methods
We searched the following electronic databases: MEDLINE, EMBASE, Social Science Citation Index, Science Citation Index, the Cochrane Database, and Bandolier, covering 1966 through 2000. The most recent copies of appropriate journals were also hand searched: JAMA, American Journal of Cardiology, Journal of the American College of Cardiology, British Medical Journal, New England Journal of Medicine, Annals of Internal Medicine, The Lancet, Circulation, Heart, European Heart Journal, and Cardiovascular Research. Search terms used were: “heart failure,” “cardiac failure,” “ventricular dysfunction,” “social class,” “socioeconomic,” “poverty,” and “deprivation.”
Inclusion criteria were all English-language abstracts/papers concerning human research relating to the subject of both SES and CHF. All clinical trials, reviews, discussion papers, and editorials were examined. Excluded were papers discussing CHF in conjunction with “pediatrics,” “protein energy malnutrition,” “cellular and animal models,” “thiamine” plus other vitamin deficiencies, “pregnancy,” or “costs of heart transplantation.” Two reviewers independently examined the reference list attained by these search methods and applied the aforementioned criteria to select papers for inclusion in this review. Both reviewers then independently studied the identified papers. We devised our own form of data collection to extract information from the identified papers. Information recorded included basic bibliographic details, type of paper (eg, a report of original research or review article), aims, study population, setting, subject selection criteria, outcome measures, and the study findings and conclusions. Where applicable, we also recorded the methodologic approaches used, as well as other factors that could affect the validity of the results, including effect modifiers. In view of the heterogeneity of the identified studies, a formal meta-analysis was deemed inappropriate. Instead, we have provided a narrative synthesis of the studies that summarizes their findings and highlights limitations, if any. We used the Oxford Centre for Evidence-Based Medicine Levels of Evidence13 to grade the studies.