TY - JOUR
PY - 2024//
TI - Estimating the causal effects of income on health: how researchers' definitions of "income" matter
JO - BMC public health
A1 - Igelström, Erik
A1 - Kopasker, Daniel
A1 - Craig, Peter
A1 - Lewsey, Jim
A1 - Katikireddi, Srinivasa Vittal
SP - e1572
EP - e1572
VL - 24
IS - 1
N2 - BACKGROUND: There is a well-established cross-sectional association between income and health, but estimates of the causal effects of income vary substantially. Different definitions of income may lead to substantially different empirical results, yet research is often framed as investigating "the effect of income" as if it were a single, easily definable construct.
METHODS/RESULTS: The aim of this paper is to introduce a taxonomy for definitional and conceptual issues in studying individual- or household-level income for health research. We focus on (1) the definition of the income measure (earned and unearned; net, gross, and disposable; real and nominal; individual and household; relative and absolute income) and (2) the definition of the causal contrast (amount, functional form assumptions/transformations, direction, duration of change, and timing of exposure and follow-up). We illustrate the application of the taxonomy to four examples from the published literature.
CONCLUSIONS: Quantified estimates of causal effects of income on health and wellbeing have crucial relevance for policymakers to anticipate the consequences of policies targeting the social determinants of health. However, much prior evidence has been limited by lack of clarity in distinguishing between different causal questions. The present framework can help researchers explicitly and precisely articulate income-related exposures and causal questions.
Language: en
LA - en SN - 1471-2458 UR - http://dx.doi.org/10.1186/s12889-024-19049-w ID - ref1 ER -