Elsevier

International Journal of Cardiology

Volume 227, 15 January 2017, Pages 635-643
International Journal of Cardiology

Review
Measuring the effects of CVD interventions and studies across socioeconomic groups: A brief review

https://doi.org/10.1016/j.ijcard.2016.10.085Get rights and content

Highlights

  • There is a known socioeconomic skew in prevalence and outcomes of CVD.

  • 5% of CVD studies looked at differences between socioeconomic groups.

  • 17% of studies looked at differences between race and ethnic groups.

Abstract

There is a known socioeconomic skew in prevalence and outcomes of cardiovascular disease (CVD). To document the proportion of clinical trials and observational studies related to CVD recently published in peer-reviewed journals that report the socio-economic distributional differences in their outcomes. We undertook a review of peer-reviewed clinical trials and observational studies relating to CVD published between 01/06/2015–31/12/2015 in PubMed; and identified the proportion that included measures of socioeconomic status and the proportion that stratified results by, or controlled for, socioeconomic status when reporting outcomes. 414 peer reviewed publications reporting the outcomes of clinical trials or observational studies that related to CVD were identified. 32 of these reported on the socioeconomic status of participants. Of these, 20 stratified the results by socioeconomic status or adjusted the results for socioeconomic status. 18 studies measured education attainment, 5 measured income, 1 measured rurality and 1 measured occupation. Of the 414 articles reporting the outcomes of clinical trials or observational studies related to cardiovascular disease in 2015, the effectiveness of the intervention, or the differences in outcomes, between socioeconomic groups was assessed in 5% of studies. This lack of consideration of the effectiveness of trial outcomes or the differences in outcomes across socioeconomic groups impairs the ability of readers, healthcare professionals and policy makers to assess the impact of new treatments or interventions in closing the inequality gap associated with CVD.

Section snippets

Background

Many chronic health conditions are known to have a socio-economic gradient, with poor outcomes more prevalent amongst groups of lower socio-economic status. There is a vast body of literature that consistently demonstrates that there is a pronounced inverse relationship between cardiovascular disease and socioeconomic status [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11]. The results of the Whitehall Study provided landmark longitudinal evidence for this: the prevalence of angina

Methods

A review of the literature was conducted by searching PubMed. A flow diagram showing how the final sample was arrived at is provided in Fig. 1.

Results

A total of 414 articles were identified that were published in the clinical trial category of PubMed and reported results relevant to cardiovascular disease. Of these, 32 reported the socioeconomic status of their participants (8%) at baseline (Table 1).

Education attainment was by far the most common baseline socio-economic variable considered (in 28 out of 32 studies), followed by income (5 out of 32 studies). Rurality (3 studies), a composite socioeconomic status measure (2 studies),

Discussion

The authors found that only a minority of CVD-related clinical trials or observational studies assess the outcomes of their studies by socioeconomic status. Despite widespread recognition of the socioeconomic gradient associated with CVD prevalence and mortality, only 5% assessed whether the outcomes differed across socio-economic groups. A recent report noted that only a minority of RCTs reporting on stroke treatments undertook a baseline assessment of the socioeconomic demographic

Conclusions

The authors recommend that more attention is given in the study design phase to measuring the socioeconomic characteristics of participants at enrolment, and in the evaluation of study outcomes, assessing the effectiveness of the trial, or differences in reported outcomes across socio-economic groups. Without explicitly measuring the outcomes of studies across socioeconomic groups, researchers may be unintentionally producing and advocating healthcare options that are less effective amongst

Funding

Part of Dr. Callander's salary came from a National Health and Medical Research Council (NHMRC) Early Career Fellowship.

Conflict of interest

The authors report no relationships that could be construed as a conflict of interest.

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    This author takes responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.

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