Randomised studies of income supplementation: a lost opportunity to assess health outcomes

Abstract

Background-Despite the wealth of evidence linking low income to ill health, there is little information from randomised studies on how much and how quickly these risks can be reversed by improvements in income. Objective-To conduct a systematic review of randomised studies of income supplementation, with particular reference to health outcomes. Design-Extensive searches of electronic databases and contact with previous authors. As well as searching for trials that were specifically designed to assess the eVects of increased income, studies of winners and losers of lotteries were also sought: if winning is purely chance, such studies are, in eVect, randomised trials of increased income. Results-Ten relevant studies were identified, all conducted in North America, mostly in the late 1960s and 1970s. Five trials were designed to assess the eVects of income supplementation on workforce participation and randomised a total of 10 000 families to 3-5 years of various combinations of minimum income guarantees and reduced tax rates. Two trials were designed to assess re-oVending rates in recently released prisoners and randomised a total of 2400 people to 3-6 months of benefits. One trial was designed to assess housing allowances and randomised 3500 families to three years of income supplements. One trial assessed the health eVects of 12 months of income supplementation in 54 people with severe mental illness. Finally, one study compared three groups of people who won diVerent amounts of money in a state lottery. In all these studies the interventions resulted in increases in income of at least one fifth. However, no reliable analyses of health outcome data are available. Conclusions-Extensive opportunities to reliably assess the eVects of increases in income on health outcomes have been missed. Such evidence might have increased the consideration of potential health eVects during deliberations about policies that have major implications for income, such as taxation rates, benefit policies, and minimum wage levels. Randomised evidence could still be obtained with innovative new studies, such as trials of full benefit uptake or prospective studies of lottery winners in which diVerent sized winnings are paid in monthly instalments over many years. (J Epidemiol Community Health 1999;53:725-730) The relation between low socioeconomic circumstances and the risks of poor health is well established.

The impact of welfare advice in primary care: a qualitative study

“…Increasing uptake of welfare benefits within primary health care has been advocated as an intervention with the potential to reduce health inequalities (Acheson, 1998;Connor et al, 1999) and this approach is supported by current government policy (Department of Social Security; Secretary of State for Health Secretary of State for Scotland, Wales and Northern Ireland, 1998; Centre for Analysis of Social Exclusion, 2001). A major function entrusted to primary care trusts is responsibility for improving the health of their populations and addressing health inequalities.…”

“…Yet little research has directly evaluated the impact of increasing resources on health (Connor et al, 1999). Reviews of interventions aimed at reducing inequalities in health found few successful approaches, mostly limited to increasing uptake of preventive services or increased knowledge of healthy behaviours (Gunning-Schepers & Gepkins, 1996;Arblaster et al, 1996).…”

“…many of the more structural interventions are likely to be considered and implemented outside the health sector'. A recent systematic review of ten North American randomised controlled trials of income supplementation carried out in the late 1960s and 1970s showed that none had reliably assessed the effects of increased income on health (Connor et al, 1999). However, one of the studies did show an association between increased income and higher birthweight babies (Kehrer & Wolin, 1979).…”

“…However, one of the studies did show an association between increased income and higher birthweight babies (Kehrer & Wolin, 1979). The authors point out that although the income maintenance experiments are unlikely to be repeated, one way of assessing the health impact of increasing financial resources on health lies with assisting claimants to obtain full welfare benefit entitlements (Connor et al, 1999).…”

Social capital and mental health

“…Poor mental health is consistently PROMOTING MENTAL HEALTH 204 • PROMOTING MENTAL HEALTH PROMOTING MENTAL HEALTH associated with poverty and deprivation, so it might be expected that increasing the incomes of the worst-off in society would improve mental and physical health, yet good evidence of the positive health effects of income supplementation still seems to escape us. A recent review attempted to identify all RCTs of the health outcomes of interventions such as negative income tax, housing allowances and other forms of financial assistance, including lotteries (Connor, Rogers & Priest, 1999). Only one small study -an RCT from Canada -assessed mental health outcomes following increases in income through loans and allowances.…”