1. Study on global AGEing and adult health (SAGE) participants
Associations between perceived income adequacy, self-rated health, and overall quality of life: Results from the Study on global AGEing and adult health (SAGE) Theresa E. Gildner1, Melissa A. Liebert1, Paul Kowal2,3, Benjamin D. Capistrant4, Somnath Chatterji2, and J. Josh Snodgrass1 1Department of Anthropology, University of Oregon, Eugene, OR; 2World Health Organization, Geneva, Switzerland; 3University of Newcastle Research Centre for Gender, Health and Ageing, Newcastle, NSW, Australia; 4Division of Epidemiology & Community Health, University of Minnesota. Minneapolis, MN
Introduction
Health outcomes are strongly related to financial situation. Financial resources can be used to improve living conditions, create health care options, and facilitate access to health promoting activities and food (Cairney, 2000; Cheng et al., 2002; Kahnerman and Deaton, 2010; Matthews and Gallo, 2011; Molarius et al., 2007). However, accurately determining individual income level can be difficult; one alternative simple measure is self-assessed income adequacy (e.g., if income is perceived as sufficient to meet the individual’s needs) (Litwin and Sapir, 2009).
Several studies have demonstrated that perceived income adequacy exhibits a significant positive relationship with both self-reported health (SRH) and quality of life (QOL) (Tucker-Seeley et al., 2013; Lawton et al., 1999). Interestingly, the relationship between reported health conditions and income adequacy appears to be especially strong in older adults (Sulander et al., 2012). Further, many studies demonstrate that older adults are more likely to report sufficient income adequacy compared to younger individuals, even at low income levels (Litwin and Sapir, 2009; Stoller and Stoller, 2003). Still, little work had been done examining these patterns cross-culturally and these relationships remain poorly understood in lower income nations.
Key Findings (cont.)
Objective Two: Perceived income adequacy significantly predicted both measures of participant well-being.
Self-rated health: In all countries, older adults who reported higher levels of income adequacy were significantly more likely to rate their health as good (p < 0.001) (Table 2).
Quality of life: In all countries, older adults who reported higher levels of income adequacy were significantly more likely to rate their quality of life as good (p < 0.001) (Table 3).
Figure 2. SAGE participants in Ghana and China being administered a questionnaire. B
Wald
p-value
Exp(B)
China (n = 8,474)***
2.185
<0.001
8.891
Ghana (n = 1,819)***
1.242
29.762
3.462
India (n = 1,976)***
1.443
45.338
4.235
Mexico (n = 991)***
1.773
14.159
5.891
Russia (n = 3,718)***
1.509
4.524
South Africa (n = 1,951)***
1.552
65.743
4.722
Methods (cont.)
Statistics: Logistic regressions were performed to examine if age (young/old dichotomous variable and age by decade) significantly predicted income security. Additional logistic regressions were performed to determine if income adequacy significantly predicted SRH or QOL. All regressions were run by country and controlled for sex, employment status, income quintile, education level, household location (urban or rural), depression, marital status, and number of people in the household.
Objectives
The present study focused on older adults in six countries and had two main objectives:
One: To examine the association between age and income adequacy by country
Two: To evaluate the relationship between income adequacy and self-reported measures of well-being (SRH and QOL)
Key Findings
Table 3. Logistic regression assessing if perceived income adequacy (0 = income insecure, 1 = income secure) significantly predicts quality of life (0 = bad QOL, 1 = good QOL), by country. The number of asterisks indicates the level of significance of the final model (*= p < 0.05, **= p < 0.01, ***= p < 0.001).
Objective One: Age significantly predicted income adequacy in each country.
Younger adults vs older adults: In China, India, Mexico, and South Africa older adults were significantly more likely to report higher income adequacy compared to their younger counterparts (p < 0.05). However, older adults in Ghana were significantly less likely to report higher income adequacy compared to younger adults (p = 0.02) (Table 1).
Age by decade: In China and Russia, a linear increase in the odds of reporting high income adequacy was observed across the decade categories compared to the year old group, suggesting that as older adults age they are more likely to report income adequacy (p < 0.001).
Study on global AGEing and adult health (SAGE) participants
This study uses data from the first wave of the World Health Organization’s SAGE project. SAGE is a longitudinal study of nationally-representative samples of older adults (>50 years old) in six middle-income countries (China, Ghana, India, Russian Federation, South Africa, and Mexico) (Fig. 1). Comparative samples of younger adults (18-49 years old) were also obtained. A household questionnaire administered to participants (Fig. 2) was used to obtain measures of income adequacy, self-reported health, subjective quality of life, and potential demographic confounders.
Discussion
As expected, SRH and QOL ratings improved as income adequacy scores increased. These findings were apparent in all six countries, suggesting that this pattern may be affected by factors beyond cultural influences. However, a uniform association between age and income adequacy ratings was not observed in all the countries. In general, older adults reported significantly higher income adequacy scores, likely due to decreased living expenses (Stoller and Stoller, 2003). However, older adults in Ghana clearly deviate from this pattern, suggesting the existence of cultural differences that shape perceptions of income adequacy. It is possible older individuals in Ghana may still be expected to financially support their extended family or may have less access to social support services. Further, a linear increase in income adequacy with age was observed only in China and Russia, perhaps due to cohort differences driven by marked social changes resulting from past political reform. These possibilities have yet to be tested. Still, the present study documented strong positive associations between ratings of perceived income adequacy and SRH or QOL in all countries. These results support previous findings in high-income populations and suggest that higher ratings of income adequacy are associated with increased subjective well-being measures in diverse nations, although age differentially impacts perceived income adequacy by country. B
Wald
p-value
Exp(B)
China (n = 9,823)***
0.530
40.123
<0.001
1.699
Ghana (n = 2,355)**
-0.349
9.416
0.002
0.706
India (n = 3,283)*
0.206
4.034
0.045
1.229
Mexico (n = 1,250)*
0.350
4.153
0.042
1.419
Russia (n = 4,150)
0.222
3.128
0.077
1.248
South Africa (n = 2,133)*
0.463
5.695
0.017
1.588
Table 1. Logistic regression assessing if age (0 = years old, 1 = 50+ years old) significantly predicts perceived income adequacy (0 = income insecure, 1 = income secure), by country. The number of asterisks indicates the level of significance of the final model (*= p < 0.05, **= p < 0.01, ***= p < 0.001).
Acknowledgments
We thank Nirmala Naidoo for her efforts in data analysis. Support for the research was provided by NIH NIA Interagency Agreement YA CN-0020; NIH R01-AG
Figure 1. Map of six SAGE countries, showing study locations. B
Wald
p-value
Exp(B)
China (n = 8,480)***
1.247
<0.001
3.481
Ghana (n = 1,820)***
0.790
18.603
2.203
India (n = 1,979)***
1.115
51.955
3.049
Mexico (n = 992)***
1.053
20.957
2.865
Russia (n = 3,757)***
0.889
2.433
South Africa (n = 1,951)***
1.040
25.559
2.830
Methods
Age Variables: Participants from all countries were pooled and divided into younger individuals (18-49 years) and older individuals (>50 years); these two groups were then coded into a dichotomous younger/older variable (younger = 0, older = 1). Older individuals were also sorted into age categories by decade (50-59; 60-69; 70-79; 80+ years old); dummy codes were then created using year olds as the reference group.
Income Adequacy: Participants reported whether they felt their income was sufficient to meet their needs (on a scale of 1-5; here 1 = “not at all”). These values were recoded to create a dichotomous measure of income security (income insecure = 0, income secure = 1).
Well-Being Variables: Participants were asked to rate their health that day and their overall quality of life (both on a scale of 1-5; here 1 = “very bad”). These values were recoded to create two dichotomous measures (SRH and QOL) of individual well being (bad SRH/QOL= 0, good SRH/QOL= 1).
References
Cairney, J. (2000). Socio-economic status and self-rated health among older Canadians. Canadian Journal on Aging, 19(4),
Cheng, Y. H., Chi, I., Boey, K. W., Ko, L. S. F., & Chou, K. L. (2002). Self-rated economic condition and the health of elderly persons in Hong Kong. Social science & medicine, 55(8),
Kahneman, D., & Deaton, A. (2010). High income improves evaluation of life but not emotional well-being. Proceedings of the National Academy of Sciences, 107(38),
Lawton, M. P. (1999). Quality of life in chronic illness. Gerontology, 45(4),
Litwin, H., & Sapir, E. V. (2009). Perceived income adequacy among older adults in 12 countries: Findings from the Survey of Health, Ageing, and Retirement in Europe. The Gerontologist, 49(3),
Matthews, K. A., & Gallo, L. C. (2011). Psychological perspectives on pathways linking socioeconomic status and physical health. Annual review of psychology 62, 501.
Molarius, A., Berglund, K., Eriksson, C., Lambe, M., Nordström, E., Eriksson, H. G., & Feldman, I. (2007). Socioeconomic conditions, lifestyle factors, and self-rated health among men and women in Sweden. The European Journal of Public Health 17(2),
Stoller, M. A., & Stoller, E. P. (2003). Perceived income adequacy among elderly retirees. Journal of Applied Gerontology, 22(2),
Sulander, T., Pohjolainen, P., & Karvinen, E. (2012). Self-rated health (SRH) and socioeconomic position (SEP) among urban home-dwelling older adults. Archives of gerontology and geriatrics, 54(1),
Tucker-Seeley, R. D., Harley, A. E., Stoddard, A. M., & Sorensen, G. G. (2013). Financial hardship and self-rated health among low-income housing residents. Health Education & Behavior, 40(4),
Table 2. Logistic regression assessing if perceived income adequacy (0 = income insecure, 1 = income secure) significantly predicts self-rated health (0 = bad SRH, 1 = good SRH), by country. The number of asterisks indicates the level of significance of the final model (*= p < 0.05, **= p < 0.01, ***= p < 0.001).