Chris Sampson’s journal round-up for 3rd October 2016

Every Monday our authors provide a round-up of some of the most recently published peer reviewed articles from the field. We don’t cover everything, or even what’s most important – just a few papers that have interested the author. Visit our Resources page for links to more journals or follow the HealthEconBot. If you’d like to write one of our weekly journal round-ups, get in touch.

Using discrete choice experiments with duration to model EQ-5D-5L health state preferences: testing experimental design strategies. Medical Decision Making [PubMedPublished 28th September 2016

DCEs are a bit in vogue for the purpose of health state valuation, so it was natural that EuroQol turned to it for valuation of the EQ-5D-5L. But previous valuation studies have highlighted challenges  associated with this approach, some of which this paper now investigates. Central to the use of DCE in this way is the inclusion of a duration attribute to facilitate anchoring from 1 to dead. This study looks at the effect of increasing the options when it comes to duration, as previous studies were limited in this regard. In this study, possible durations were 6 months or 1, 2, 4, 7 or 10 years. 802 online survey respondents we presented with 10 DCE choice sets, and the resulting model had generally logically ordered coefficients. So the approach looks feasible, but it isn’t clear whether or not there are any real advantages to including more durations. Another issue is that the efficiency of the DCE design might be improved by introducing prior information from previous studies to inform the selection of health profiles – that is, by introducing non-zero prior values. With 800 respondents, this design resulted in more disordering with – for example – a positive coefficient on level 2 for the pain/discomfort dimension. This was not the expected result. However, the design included a far greater proportion of more difficult choices, which the authors suggest may have resulted in inconsistencies. An alternative way of increasing efficiency might be to use a 2-stage approach, whereby health profiles are selected and then durations are selected based on information from previous studies. Using the same number of pairs but a sample half the size (400), the 2-stage design seemed to work a treat. It’s a promising design that will no doubt see further research in this context.

Is the distribution of care quality provided under pay-for-performance equitable? Evidence from the Advancing Quality programme in England. International Journal for Equity in Health [PubMedPublished 23rd September 2016

Suppose a regional health care quality improvement initiative worked, but only for the well-off. Would we still support it? Maybe not, so it’s important to uncover for whom the policy is working. QOF is the most-studied pay-for-performance programme in England and it does not seem to have reduced health inequalities in the context of primary care. There is less evidence regarding P4P in hospital care, which is where this study comes in by looking at the Advancing Quality initiative across five different health conditions. Using individual-level data for 73,002 people, the authors model the probability of receiving a quality indicator according to income deprivation in their local area. There were 23 indicators altogether, across which the results were not consistent. Poorer patients were more likely to receive pre-surgical interventions for hip and knee replacements and for coronary artery bypass grafting (CABG). And poorer people were less likely to receive advice at discharge. On the other hand, for hip and knee replacement and CABG, richer people were more likely to receive diagnostic tests. The main finding is that there is no obvious systematic pro-poor or pro-rich bias in the effects of this pay-for-performance initiative in secondary care. This may not be a big surprise due to the limited amount of self-selection and self-direction for patients in secondary care, compared with primary care.

The impact of social security income on cognitive function at older ages. American Journal of Health Economics [RePEc] Published 19th September 2016

Income correlates with health, as we know. But it’s useful to be more specific – as this article is – in order to inform policy. So does more social security income improve cognitive function at older ages? The short answer is yes. And that wasn’t a foregone conclusion as there is some evidence that higher income leads to earlier retirement, which in turn can be detrimental to cognitive function. In this study the authors use changes in the Social Security Act in the US in the 1970s. Between 1972 and 1977, Congress messed up a bit and temporarily introduced a policy that made payments increase at a rate faster than inflation, which was therefore enjoyed by people born between 1910 and 1916, with a 5 year gradual transition until 1922. Unsurprisingly, this study follows many others that have made the most of this policy quirk. Data are taken from a longitudinal survey of older people, which includes a set of scores relating to cognition, with a sample of 4139 people. Using an OLS model, the authors estimate the association between Social Security income and cognition. Cognition is measured using a previously developed composite score with 3 levels: ‘normal’, ‘cognitively impaired’ and ‘demented’. To handle the endogeneity of income, an instrumental variable is constructed on the basis of year of birth to tie-in with the peak in benefit from the policy (n=673). In today’s money the beneficiary cohort received around $2000 extra. It’s also good to see the analysis extended to a quantile regression to see whereabouts in the cognition score distribution effects accrue. The additional income resulted in improvements in working memory, knowledge, languages and orientation and overall cognition. The effects are strong and clinically meaningful. A $1000 (in 1993 prices) increase in annual income lead to a 1.9 percentage point reduction in the likelihood of being classified as cognitively impaired. The effect is strongest for those with higher levels of cognition. The key take-home message here is that even in older populations, policy changes can be beneficial to health. It’s never too late.

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Sam Watson’s journal round-up for 9th May 2016

Every Monday our authors provide a round-up of some of the most recently published peer reviewed articles from the field. We don’t cover everything, or even what’s most important – just a few papers that have interested the author. Visit our Resources page for links to more journals or follow the HealthEconBot. If you’d like to write one of our weekly journal round-ups, get in touch.

The association between income and life expectancy in the United States, 2001-2014. JAMA [PubMedPublished 26th April 2016

The relationship between wealth, income, and health has been examined in many hundreds of studies. The relationship is complex and still not well understood. Individual material circumstances affect patterns of consumption and health behaviours; relative socioeconomic position modifies these effects through psychosocial stressors and social patterns of behaviour; environmental and other neighbourhood factors also have further influences. So, what sets this study apart? It uses data from 1.4 billion tax records from citizens of the United States (p-values are still reported however!). Adults aged 40-76 from 1999 to 2014 are included. The authors find a gap in life expectancy of 15 years for men and 10 years for women between the top and bottom 1% of the income distribution. This gap increased over time with gains to life expectancy in the top quintile of the income distribution larger than those in the bottom between 2001-2014. There were also significant differences within income quintiles between high and low income areas, which were also correlated with health behaviors. This study provides a fascinating and comprehensive overview of income and health in the US. However, it does not really further our understanding of how these various relationships work, despite some bold claims.

The effects of exposure to better neighborhoods on children: new evidence from the Moving to Opportunity experiment. American Economic Review [RePEcPublished April 2016

The previous study in this round-up showed that there was a wide variation in changes to life expectancy over time for individuals in the bottom income quintile by geographic area. Between 2001 and 2014 changes to life expectancy varied between an increase of four years to a decrease of two years. But, these correlations don’t really provide enough information to formulate policy; is it the individuals in the neighbourhood or the neighbourhood itself? One way of investigating this would be to randomly provide the opportunity to move from a high poverty to a low poverty area and investigate the outcomes. In the 1990s the Moving to Opportunity (MtO) experiment provided vouchers to families to move to better neighbourhoods. Previous investigations of the effects of these vouchers found that families who moved had better physical and mental health, subjective well being, and safety but did not find evidence of improvements to employment or earnings. This present study examines the outcomes for those who were children at the time of the MtO program. Circumstances in early life, even as early as birth, are hypothesised to be important to later life outcomes. People who were part of families who were assigned vouchers and who were aged under 13 at the time of the program had greater earnings in their 20s and were more likely to attend college. These effects were not replicated in those aged 13-18 at the time of the MtO program.

Responding to risk: circumcision, information, and HIV prevention. The Review of Economics and Statistics Published May 2016

Understanding how people respond to new information on risk is important to formulate effective health policy. If individuals perceive their risk of an adverse health outcome to be low they may engage in riskier behaviours and conversely for those with perceived high risk. The net effect of greater health education is therefore ambiguous. This study investigates the effect of the perception of the risk of contracting HIV on the practice of safe sex among males in Malawi. Male circumcision can reduce the risk of transmission of HIV by up to 60%, thus circumcised males are at lower risk than their uncircumcised counterparts. The study included both circumcised and uncircumcised males and provided information about HIV transmission and circumcision to a random set of the participants in the study. The study found that the low risk (circumcised) males did not engage in more risky sexual behaviour while the higher risk (uncircumcised) males both reduced the frequency of sex and increased their use of condoms. Extrapolating from these results, this study may suggest that an increase in information has an overall positive effect by reducing risk.

Marginalism, reductionism, realism

There is a large literature documenting the socioeconomic gradient in health. Whether it be measured by education, income or some other metric, individuals of a lower socioeconomic status have worse health. Understanding and explaining this gradient is of great importance to improving public health; however, the way we approach investigation and application depends on our ontological and epistemological position which is often not addressed in practice but is implicit in any analysis we do.

Many have tried to explain socioeconomic gradients in health through either access to healthcare or genetics. But, gradients have widened over time within countries with little change to the genetic make-up of the population; and, there is often little difference in measured gradients between countries with universal healthcare funded through taxation (e.g. the UK) and insurance funded healthcare with known access issues (e.g. the US) (Dow and Rehkopf, 2010).

This then leads us to differences in risk factors for the main causes of death in Western nations. There does exist well documented gradients in obesity and smoking. But, gradients in exposure to risk factors often differ from gradients in mortality; for example, Southern European countries have a wider mortality gradient than Northern European countries but have a narrower obesity gradient (Mackenbach et al, 2008). Although, smoking may better explain this difference. To succinctly summarise this – it is a complex relationship.

Our aim as researchers is to obtain knowledge about this system to attempt to provide causal explanations of relationships between social and economic changes and biological outcomes. Clearly, we should have in mind that our explanations need to have a plausible biological aetiology. But, focussing here on solely the social and economic factors, we need to consider our ontological position.

The neoclassical approach posits individual, atomistic agents maximising utility by making rational choices about consumption and investment in health. This approach is exemplified by the Grossman (1972) model. Individuals ‘demand’ health on the basis of the cost of health capital and rate of depreciation. One immediate philosophical objection to this set up is the implicit dualism – the separation between the mind (the rational decision maker) and their body (their health). This dualism clearly makes little sense when mental health is considered. A more tangible objection arises since these models only consider agency and not structure. An implication of these models are that individuals’ choices about health related goods and behaviour are determined by their relative costs to the individual; there is little or no allowance for decisions to be affected by culture or society. It is ideologically individualistic.

Piero Sraffa, an influential Italian economist, developed a critique of the neoclassical approach (strictly speaking it was a ‘prelude to a critique’). One of his objections was with marginalism. He was writing about production in the economy and the problem of estimating the marginal product of a particular factor of production. He argued that the marginal product didn’t make sense since any change to the levels of any one of the factors of production would change the way it combines with any other factors of production, and the proportions they combine in. When we consider the aforementioned health ‘production functions’, we have the same issue. Merely altering income will not necessarily change health since the way in which income combines with, say, education or the local environment, will change. At the societal level, the way these interact are the result of institutions, ideology and culture.

Thus, when we estimate the effect of socioeconomic factors on health outcomes, we should, at a minimum, allow for differential effects by socioeconomic status. In interpretation and application, it may suggest that a policy of just redistributing income may not be enough – a better understanding of individual motives and heterogeneous culture is required to target policy. Many branches of economics that are considered heterodox, such as institutional economics, post-Keynesian economics and political economy analysis take account of social norms and economic institutions. But, the roles of sociology and psychology are also of great importance. This suggests the need for methodological pluralism, certainly when examining socioeconomic determinants of health, but also in general. It is perhaps best summarised by the following quote from Keynes:

The master-economist must possess a rare combination of gifts …. He must be mathematician, historian, statesman, philosopher — in some degree. He must understand symbols and speak in words. He must contemplate the particular, in terms of the general, and touch abstract and concrete in the same flight of thought. He must study the present in the light of the past for the purposes of the future. No part of man’s nature or his institutions must be entirely outside his regard. He must be purposeful and disinterested in a simultaneous mood, as aloof and incorruptible as an artist, yet sometimes as near to earth as a politician.