Abstract
Objectives
Poverty, often defined as a lack of resources to achieve a living standard that is deemed acceptable by society, may be assessed using level of income or a measure of individual deprivation. However, the relationship between low income and deprivation is complex—for example, not everyone who has low income is deprived (and vice versa). In addition, longitudinal studies show only a small relationship between short-term changes in income and health but an alternative measure of poverty, such as deprivation, may have a stronger association with health over time. We aim to compare low income and individual deprivation as predictors of self-rated health (SRH), using longitudinal survey data, to test the hypothesis that different measures of poverty may have different associations with health.
Methods
We used three waves from the longitudinal Survey of Family, Income and Employment and fixed-effect linear regression models to compare low income (<50% median income at each wave) and deprivation (reporting three or more items from the New Zealand individual deprivation index) as predictors of SRH (coded 1–5; SD 1.1–1.2). We also compared the impact of duration of low income and deprivation on SRH using mixed linear models.
Results
In the fixed-effect models, moving into deprivation between waves was associated with a larger decline in SRH compared to moving into low income, which persisted in models including both low income and deprivation. Similar findings were observed for duration of low income and deprivation in mixed models.
Conclusions
Moving into high levels of individual deprivation is a stronger predictor of changes in SRH than moving into low income. When investigating the association of hardship poverty with health, using alternative measures, in addition to income, is advisable.
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References
Allison PD (2005) Fixed effects regression analysis for longitudinal data using SAS. SAS Institute Inc, Cary, NC
Apouey B, Clark AE (2009) Winning big but feeling no better? The effect of lottery prizes on physical and mental health. PSE Working Paper 09. Paris School of Economics (Ecole normale supérieure), Paris
Bechtel L, Lordan G, Rao DSP (2012) Income inequality and mental health–empirical evidence from Australia. Health Econ 21:4–17. http://www3.interscience.wiley.com/cgi-bin/jhome/5749
Benzeval M, Judge K (2001) Income and health: the time dimension. Soc Sci Med 52(9):1371–1390
Bound J, Brown C, Mathiowetz N (2001) Measurement error in survey data. In: Heckman J, Leamer EE (eds) Handbook of econometrics, vol 5. Elsevier, Amsterdam, pp 3705–3843
Buddelmeyer H, Cai L (2009) Interrelated dynamics of health and poverty in Australia. Discussion Paper Series. IZA DP No. 4602, Institute for the Study of Labor, Bonn
Butterworth P, Rodgers B, Windsor TD (2009) Financial hardship, socio-economic position and depression: results from the PATH Through Life Survey. Soc Sci Med 69(2):229–237
Carter KN, Cronin M, Blakely T, Hayward M, Richardson K (2010) Cohort Profile: Survey of Families, Income and Employment (SoFIE) and Health Extension (SoFIE-Health). Int J Epidemiol 39(3):653–659
Case A, Fertig A, Paxson C (2005) The lasting impact of childhood health and circumstance. J Health Econ 24(2):365–389
Costello EJ, Compton SN, Keeler G, Angold A (2003) Relationships between poverty and psychopathology: a natural experiment. JAMA 290(15):2023–2029
de Castro A, Gee G, Takeuchi D (2010) Examining alternative measures of social disadvantage among Asian Americans: the relevance of economic opportunity, subjective social status, and financial strain for health. J Immigr Minor Health 12(5):659–671. doi:10.1007/s10903-009-9258-3
Dowd JB (2012) Whiners, deniers, and self-rated health: what are the implications for measuring health inequalities? A commentary on Layes, et al. Soc Sci Med 75(1):10–13. doi:10.1016/j.socscimed.2012.01.036
Every Child Counts (2010) Eradicating child poverty in New Zealand. Every Child Counts, Wellington
Galobardes B, Lynch JW, Smith GD (2008) Is the association between childhood socioeconomic circumstances and cause-specific mortality established? Update of a systematic review. J Epidemiol Community Health 62(5):387–390. doi:10.1136/jech.2007.065508
Georgiades A, Janszky I, Blom M, Laszlo KD, Ahnve S (2009) Financial strain predicts recurrent events among women with coronary artery disease. Int J Cardiol 135(2):175–183. doi:18619689
Gibb SJ, Fergusson DM, Horwood LJ (2012) Childhood family income and life outcomes in adulthood: findings from a 30-year longitudinal study in New Zealand. Soc Sci Med 74(12):1979–1986. doi:10.1016/j.socscimed.2012.02.028
Gottschalk P, Huynh M (2010) Are earnings inequality and mobility overstated? The impact of nonclassical measurement error. Rev Econ Stat 92(2):302–315
Groffen DAI, Bosma H, van den Akker M, Kempen G, van Eijk JTM (2008) Material deprivation and health-related dysfunction in older Dutch people: findings from the SMILE study. Eur J Public Health 18(3):258–263
Imlach Gunasekara F, Carter K, Blakely T (2011a) Change in income and change in self-rated health: Systematic review of studies using repeated measures to control for confounding bias. Soc Sci Med 72(2):193–201. doi:10.1016/j.socscimed.2010.10.029
Imlach Gunasekara F, Carter K, Liu I, Richardson K, Blakely T (2011b) The relationship between income and health using longitudinal data from New Zealand. J Epidemiol Community Health. doi:10.1136/jech.2010.125021
Jensen J (1988) Income equivalences and the estimation of family expenditures on children. Department of Social Welfare, Wellington
Jones AM, Wildman J (2008) Health, income and relative deprivation: evidence from the BHPS. J Health Econ 27(2):308–324
Kaufman JS (2011) Commentary: money and models: double-edged swords. Int J Epidemiol 40(4):1091–1093. doi:10.1093/ije/dyr093
Krieger N (2001) A glossary for social epidemiology. J Epidemiol Community Health 55(10):693–700
Kuh D, Ben-Shlomo Y (2004) A life-course approach to chronic disease epidemiology, 2nd edn. Oxford University Press, Oxford
Lindahl M (2005) Estimating the effect of income on health and mortality using lottery prizes as an exogenous source of variation in income. J Hum Resour 40(1):144–168. doi:10.3368/jhr.XL.1.144
Lorant V, Croux C, Weich S, Deliege D, Mackenbach J, Ansseau M (2007) Depression and socio-economic risk factors: 7-year longitudinal population study. Br J Psychiatry 190:293–298
Lukiyanova A, Oshchepkov A (2012) Income mobility in Russia (2000–2005). Econ Syst 36(1):46–64. doi:10.1016/j.ecosys.2011.10.001
Nedjat S, Hosseinpoor AR, Forouzanfar MH, Golestan B, Majdzadeh R (2012) Decomposing socioeconomic inequality in self-rated health in Tehran. J Epidemiol Community Health 66(6):495–500. doi:10.1136/jech.2010.108977
Perry B (2002) The mismatch between income measures and direct outcome measures of poverty. Soc Policy J N Z 19:101–127
Perry B (2011) Household incomes in New Zealand: trends in indicators of inequality and hardship 1982 to 2010. Ministry of Social Development, Wellington
Pfoertner T-K, Andres H-J, Janssen C (2011) Income or living standard and health in Germany: different ways of measurement of relative poverty with regard to self-rated health. Int J Public Health 56:373–384
Pischke J-S (1995) Measurement error and earnings dynamics: some estimates from the PSID Validation Study. J Bus Econ Stat 13(3):305–314
Poulton R, Caspi A, Milne BJ, Thomson WM, Taylor A, Sears MR, Moffitt TE (2002) Association between children’s experience of socioeconomic disadvantage and adult health: a life-course study. Lancet 360(9346):1640–1645
Ringen S (1988) Direct and indirect measures of poverty. J Soc Policy 17(3):351–365
Sacker A, Wiggins R, Bartley M, McDonough P (2007) Self-rated health trajectories in the United States and the United Kingdom: a comparative study. Am J Public Health 97(5):812–818
Salmond C, Crampton P, King P, Waldegrave C (2006) NZiDep: A New Zealand index of socioeconomic deprivation for individuals. Soc Sci Med 62(6):1474–1485. doi:10.1016/j.socscimed.2005.08.008
Schmeiser MD (2009) Expanding wallets and waistlines: the impact of family income on the BMI of women and men eligible for the earned income tax credit. Health Econ 18(11):1277–1294
Schulz AJ, Israel BA, Zenk SN, Parker EA, Lichtenstein R, Shellman-Weir S, Klem AB (2006) Psychosocial stress and social support as mediators of relationships between income, length of residence and depressive symptoms among African American women on Detroit’s eastside. Soc Sci Med 62(2):510–522. doi:10.1016/j.socscimed.2005.06.028
Sedgwick P (2012) What are odds? BMJ 344. doi:10.1136/bmj.e2853
Spicker P, Alvarez Leguizamón S, Gordon D (2006) Poverty: an international glossary, 2nd edn. Zed Books, London
Stillman A, Gibson J, McKenzie D (2012) The impact of immigration on child health: experimental evidence from a migration lottery program. Econ Inq 50(1):62–81
Townsend P (1979) Poverty in the United Kingdom. Allen Lane and Penguin Books, London
Tubeuf S, Jusot F, Bricard D (2012) Mediating role of education and lifestyles in the relationship between early-life conditions and health: evidence from the 1958 British Cohort. Health Econ 21:129–150. doi:10.1002/hec.2815
United Nations Development Programme (2010) Human Development Report 2010. United Nations Development Programme, New York
Whelan CT, Layte R, Maitre B (2003) Persistent income poverty and deprivation in the European Union: an analysis of the first three waves of the European Community Household Panel. J Soc Policy 32(1):1–18
Wooldridge JM (2002) Econometric analysis of cross section and panel data. MIT Press, Cambridge, MA
Yang T-C, Chen VY-J, Shoff C, Matthews SA (2012) Using quantile regression to examine the effects of inequality across the mortality distribution in the U.S. counties. Soc Sci Med 74(12):1900–1910. doi:10.1016/j.socscimed.2012.02.029
Yoo JP, Slack KS, Holl JL (2009) Material hardship and the physical health of school-aged children in low-income households. Am J Public Health 99(5):829–836. doi:10.2105/ajph.2007.119776
Acknowledgments
Survey of Family, Income and Employment Health was primarily funded by the Health Research Council of New Zealand (reference 08/048) as part of the Health Inequalities Research Programme. Ethics approval for the SoFIE-Health module was obtained from the University of Otago Human Ethics Committee. Ethical oversight of SoFIE was governed by the Statistics Act 1975, as SoFIE was administered as part of the work programme of Statistics New Zealand. Access to the data used in this study was provided by Statistics New Zealand in a secure environment designed to give effect to the confidentiality provisions of the Statistics Act 1975. The results in this study and any errors contained therein are those of the author, not Statistics New Zealand.
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Imlach Gunasekara, F., Carter, K.N., Crampton, P. et al. Income and individual deprivation as predictors of health over time. Int J Public Health 58, 501–511 (2013). https://doi.org/10.1007/s00038-013-0450-9
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DOI: https://doi.org/10.1007/s00038-013-0450-9