Table 3 Early‐life indicators of income.

Indicator	Location, study design	Indicators of SEP measured	Criteria
Family income during childhood	Australia, longitudinal Mater—University of Queensland Study of Pregnancy and its Outcomes48,57	P	Validity:Poor family financial situation is an important childhood characteristic in the explanation of socioeconomic inequalities in health56Relevance: May be affected by inflation over time, or changing criteria for definitions of povertyReliability:Potentially affected by recall bias and poor response rates Timeframe or age within indicator question may affect responses, as circumstances may change throughout early lifeDeconstruction:Economic distress construct could be broken down into component parts if necessary
	USA, Woodlawn Cohort Study75	P
Family income when participant aged 13 years	Brazil, Cross‐sectional, Cianorte Survey of School Children64,65	P
Household income when participant aged 18 years	USA, Wisconsin Longitudinal Study76	P
Economic distress construct in childhood based on receipt of public assistance or welfare, inability to pay for food, rent or mortgage, not having enough money to make ends meet, or borrowing money to pay for medical expenses	USA, Longitudinal Harvard Study of Moods and Cycles74	R
Degree to which family was considered wealthy	Finland, Longitudinal Kuopio Ischaemic Heart Disease Risk Factor Study68,69,70	R
Receipt of state welfare benefits	Australia, Longitudinal Mater—University of Queensland Study of Pregnancy and its Outcomes48,57	P
	1970 British Birth Cohort77	P
Free school meals or on supplementary benefit	1958 British Birth Cohort78	P
Household poverty status when participant born and aged 7 years	USA, Longitudinal National Collaborative Perinatal Project59,60	P
Period of 6 months during child hood when family was on welfare	USA, Cross‐sectional National Survey of Midlife Development54	R
Number of times household income was at least 200% below poverty line	USA, Longitudinal Alameda County Study39	R
Financial circumstances during childhood	The UK, Longitudinal Whitehall Study35	R
	The Netherlands, Longitudinal Study of Socio‐Economic Health Differences58	R
	Sweden, Longitudinal level of living surveys79	R

*P, prospectively; R, retrospectively; SEP, socioeconomic position.