Life course analysis on income and incident AMI: a Danish register-based cohort study

Association of socioeconomic status with cardiovascular disease and cardiovascular risk factors: a systematic review and meta-analysis

Aim

Cardiovascular disease (CVD) remains one of the leading causes of mortality worldwide, and several studies have indicated the association between socioeconomic status (SES) with CVD and cardiovascular risk factors (CVRFs). It is necessary to elucidate the association of SES and CVRFs with CVD.

Subject and methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library for publications, using "socioeconomic status," "cardiovascular disease," and corresponding synonyms to obtain literature. The quality of studies was evaluated using the National Institutes of Health Quality Assessment Tool (NIH-QAT). All analyses were performed using Stata V.12.0.

Results

There were 31 eligible studies included in this meta-analysis. All studies presented a low risk of bias via NIH-QAT assessment. As for CVD incidence/mortality, pooled hazard ratios (HR) of low and middle vs. high income were [HR = 1.22 (1.17-1.28); HR = 1.12 (1.09-1.16)] and [HR = 1.37 (1.21-1.56); HR = 1.19 (1.06-1.34)]. The HR of education were [HR = 1.44 (1.28-1.63); HR = 1.2 (1.11-1.3)] and [HR = 1.5 (1.22-1.83); HR = 1.13 (1.05-1.22)]. The HR of deprivation were [HR = 1.28 (1.16-1.41); HR = 1.07 (1.03-1.11)] and [HR = 1.19 (1.11-1.29); HR = 1.1 (1.02-1.17)]. SES was negatively correlated with CVD outcomes. A subgroup analysis of gender and national income level also yielded a negative correlation, and additional details were also obtained.

Conclusions

SES is inversely correlated with CVD outcomes and the prevalence of CVRFs. As for CVD incidence, women may be more sensitive to income and education. In terms of CVD mortality, men may be more sensitive to income and education, and people from low- and middle-income countries are sensitive to income and education.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01825-4.

Socioeconomic position and first-time major cardiovascular event in patients with type 2 diabetes: a Danish nationwide cohort study

AIMS 

The association between socioeconomic position and cardiovascular disease has not been well studied in patients with type 2 diabetes. We aimed to examine the association between socioeconomic position and first-time major adverse cardiovascular events (MACE) in patients with type 2 diabetes.

METHODS AND RESULTS 

Through the Danish nationwide registers, we identified all residents with newly diagnosed type 2 diabetes between 2012 and 2017. Based on sex-stratified multivariable cause-specific Cox regression models, we calculated the standardized absolute 5-year risk of the composite outcome of first-time myocardial infarction, stroke, or cardiovascular mortality (MACE) according to income quartiles. A total of 57 106 patients with type 2 diabetes were included. During 155 989 person years, first-time MACE occurred in 2139 patients. Among both men and women, income was inversely associated with the standardized absolute 5-year risk of MACE. In men, the 5-year risk of MACE increased from 5.7% [95% confidence interval (CI) 4.9-6.5] in the highest income quartile to 9.3% (CI 8.3-10.2) in the lowest income group, with a risk difference of 3.5% (CI 2.4-4.7). In women, the risk of MACE increased from 4.2% (CI 3.4-5.0) to 6.1% (CI 5.2-7.0) according to income level, with a risk difference of 1.9% (CI 0.8-2.9).

CONCLUSION 

Despite free access to medical care in Denmark, low-socioeconomic position was associated with a higher 5-year risk of first-time MACE in patients with incident type 2 diabetes. Our results suggest prevention strategies could be developed specifically for patients with low-socioeconomic position.

Income and housing satisfaction and their association with self-rated health in different life stages. A fixed effects analysis using a German panel study

OBJECTIVE

We aim to investigate the effect of income and housing satisfaction on self-rated health in different life stages.

DESIGN

A population-based panel study (German Socio-Economic Panel).

PARTICIPANTS

The final sample consisted of 384 280 observations from 50 004 persons covering the period between 1994 and 2016.

OUTCOME MEASURES

Average marginal effects were calculated based on fixed effects regressions to obtain the effect of changes in income and housing satisfaction on changes in self-rated health for each year of age. Self-rated health was assessed on a 5-point scale, with higher values indicating better health.

RESULTS

Changes in income and housing satisfaction showed a small association with changes in self-rated health. The association was stronger for income, where it also varied considerably in different life stages. The average marginal effects for income satisfaction varied between 0.02 and 0.05 in men and 0.02 and 0.04 in women and peaked between the ages of 55-60. For housing satisfaction, average marginal effects ranged from 0.02 to 0.04 (men) and from 0.02 to 0.03 (women).

CONCLUSION

Higher satisfaction with housing and income was associated with better self-rated health. Therefore, studies on the social determinants of health should not only focus on objective material conditions but also on how individuals perceive and evaluate their situation.

Sex differences in health and mortality by income and income changes

BACKGROUND

The adverse association between income, health and survival is well documented, but little is known about how income trajectories influence health and survival for men and women. We aim to investigate sex differences in mortality and hospitalisations by income and income changes.

METHODS

We performed a population-based, nationwide study including 1 063 787 Danes born 1935-1955 and residing in Denmark during 1980-2015. Income was calculated during two age intervals: 45-49 and 55-59 years. The average income was divided into quartiles for men and women separately, which formed the basis for the income trajectories. Individuals were followed up from age 60 until 2014/2015 for hospital admission and mortality, respectively.

RESULTS

Men had higher mortality and were more hospitalised than women. Sex differences in mortality were most pronounced for people with stable low income (relative difference in hazard=1.93; 95% CI 1.89 to 1.98) and a downward income trajectory (1.91; 95% CI 1.85 to 1.98) with smaller sex differences for people with an upward trajectory (1.59; 95% CI 1.56 to 1.62) and stable high income (1.37; 95% CI 1.33 to 1.41). A similar pattern was found for family income. Regarding hospitalisations, similar results were found, though less pronounced. Investigation of mortality and hospitalisations by all possible trajectories demonstrated that income at ages 55-59 was an important predictor of mortality, with increasing mortality for decreasing income quartile.

CONCLUSION

Income trajectories as a proxy for change in social position have a larger influence on men's than women's health and mortality. Income in the late 50s is an important predictor of mortality, particularly for men.