Sam Watson’s journal round-up for Monday 20th August 2018

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.

A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest. New England Journal of Medicine. Published July 2018.

Adrenaline (epinephrine) is often administered to patients in cardiac arrest in order to increase blood flow and improve heart rhythm. However, there had been some concern about the potential adverse effects of using adrenaline, and a placebo controlled trial was called for. This article presents the findings of this trial. While there is little economics in this article, it is an interesting example of what I believe to be erroneous causal thinking, especially in the way it was reported in the media. For example, The Guardian‘s headline was,

Routine treatment for cardiac arrest doubles risk of brain damage – study

while The Telegraph went for the even more inflammatory

Cardiac arrest resuscitation drug has needlessly brain-damaged thousands

But what did the study itself say about their findings:

the use of epinephrine during resuscitation for out-of-hospital cardiac arrest resulted in a significantly higher rate of survival at 30 days than the use of placebo. […] although the rate of survival was slightly better, the trial did not show evidence of a between-group difference in the rate of survival with a favorable neurologic outcome. This result was explained by a higher proportion of patients who survived with severe neurologic disability in the epinephrine group.

Clearly, a slightly more nuanced view, but nevertheless it leaves room for the implication that the adrenaline is causing the neurological damage. Indeed the authors go on to say that “the use of epinephrine did not improve neurologic outcome.” But a counterfactual view of causation should lead us to ask what would have happened to those who survived with brain damage had they not been given adrenaline.

We have a competing risks set up: (A) survival with favourable neurologic outcome, (B) survival with neurologic impairment, and (C) death. The proportion of patients with outcome (A) was slightly higher in the adrenaline group (although not statistically significant so apparently no effect eyes roll), the proportion of patients with outcome (B) was a lot higher in the adrenaline group, and the proportion of patients with outcome (C) was lower in the adrenaline group. This all suggests to me that the adrenaline caused patients who would have otherwise died to mostly survive with brain damage, and a few to survive impairment free, not that adrenaline caused those who would have otherwise been fine to have brain damage. So the question in response to the above quotes is then, is death a preferable neurologic outcome to brain damage? As trite as this may sound, it is a key health economics question – how do we value these health states?

Incentivizing Safer Sexual Behavior: Evidence from a Lottery Experiment on HIV Prevention. American Economic Review: Applied Economics. [RePEcPublished July 2018. 

This article presents a randomised trial testing an interesting idea. People who are at high risk of HIV and other sexually transmitted infections (STIs) and often those who engage in riskier sexual behaviour. A basic decision theoretic conception would be that those individuals don’t consider the costs to be high enough relative to the benefits (although there is clearly some divide between this explanation and how people actually think in terms of risky sexual behaviour, much like any other seemingly irrational behaviour). Conditional cash transfers can change the balance of the decision to incentivise people to act differently, what this study looks at is using a conditional lottery with the chance of high winnings instead, since this should be more attractive still to risk-seeking individuals. While the trial was designed to reduce HIV prevalance, entry into the lottery in the treatment arm was conditional on being free of two curable STIs at each round – this enabled people who fail to be eligible again, and also allowed the entry of HIV-positive individuals whose sexual behaviour is perhaps the most important to reducing HIV transmission. The lottery arm of the trial was found to have 20% lower incidence over the study period compared to the control arm – quite impressive. However, the cost-effectiveness of the program was estimated to be $882 per HIV infection averted on the basis of lottery payments alone, and around $3,300 per case averted all in. This seems quite high to me. Despite a plethora of non-comparable outcomes in cost-effectiveness studies of HIV public health interventions other studies have reported costs per cases averted an order of magnitude lower than this. The conclusions seems to be then that the idea works well – it’s just too costly to be of much use.

Monitoring equity in universal health coverage with essential services for neglected tropical diseases: an analysis of data reported for five diseases in 123 countries over 9 years. The Lancet: Global Health. [PubMedPublished July 2018. 

Universal health coverage (UHC) is one the key parts of Sustainable Development Goal (SDG) 3, good health and well-being. The text of the SDG identifies UHC as being about access to services – but this word “access” in the context of health care is often vague and nebulous. Many people mistakenly treat access to health services as synonymous with use of health services, but having access to something is not dependent on whether you actually use it or not. Barriers to a person’s ability to use health care for a given complaint are numerous: financial cost, time cost, lack of education, language barrier, and so forth. It is therefore difficult to quantify and measure access. Hogan and co-authors proposed an index to quantify and monitor UHC across the world that was derived from a number of proxies such as women with four or more antenatal visits, children with vaccines, blood pressure, and health worker density. Their work is useful but of course flawed – these proxies all capture something different, either access, use, or health outcomes – and it is unclear that they are all sensitive to the same underlying construct. Needless to say, we should still be able to diagnose access issues from some combination of these data. This article extends the work of Hogan et al to look at neglected tropical diseases, which affect over 1.5 billion, yet which are, obviously, neglected. The paper uses ‘preventative chemotherapy coverage’ as its key measure, which is the proportion of those needed the chemotherapy who actually receive it. This is a measure of use and not access (although they should be related), for example, there may be near universal availability of the chemotherapy, but various factors on the demand side limiting use. Needless to say, the measure should still be a useful diagnostic tool and it is interesting to see how much worse countries perform on this metric for neglected tropical diseases than general health care.

 

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Are user fees a barrier to health care in poor countries?

The 1987 Bamako declaration promoted user or consultation fees for health care as a means to raise revenue and improve the quality of services. However, user fees may pose a barrier to access, and hence the key Sustainable Development Goal of Universal Health Coverage (UHC), for the global poor who typically have a high elasticity of demand for health services. The evidence has been mixed though on the impact of adding or removing user fees. A Cochrane review found that utilisation of services typically declined significantly with the introduction of fees and that quality was often found to improve with fees, but they also questioned the reliability of these studies due to a “high risk of bias”. Indeed, the evidence can be conflicting as to the effect of user fees on health service utilisation. Consider the following two studies from two similar countries: Malawi and Zambia.

The first looks at the effect the introduction and removal user fees had on health centre outpatient attendances, new diagnoses of malaria, and HIV diagnoses in a rural district of Malawi (which I should declare I authored!) Of 13 centres in Neno district, four were operated by the Christian Health Association of Malawi, of which one has always charged user fees and three introduced them in July 2013. The other centres were operated by the Ministry for Health and an NGO, Partners In Health, and did not charge fees. In July 2015, one centre removed user fees. These changes in charging status created a neat natural experiment. A plot of outpatient attendances shows what happened:

Figure 3

Even without modelling it is clear what happened – attendances dropped with the introduction of user fees and increased when they were removed. Similar changes were seen in new malaria and HIV diagnoses Further analysis also suggested patients weren’t moving between centres to avoid fees.

The second study, published this week, looks at a 2006 policy to remove user fees for publicly-funded health care facilities in rural districts across Zambia. The policy was instigated by the Zambian president as a step towards UHC, but was implemented haphazardly with funding not being completely in place and districts choosing to distribute the funding they received in different ways. Using data from a repeated cross-sectional health survey, the corresponding plot of the effects of the policy is:

userfees

Evident from this and reinforced by their synthetic control analysis, the policy did little to change the proportion of people seeking health care. The key impact of the policy was to reduce out of pocket expenditure as it seems people switched from using private providers to public providers. So why do the results of these studies, with seemingly similar ‘treatments’ in similar poor rural populations, differ so much?

In an earlier study of the Zambian policy it was found that outpatient attendances recorded in routine data – the same data used in the Malawi study above – there were large increases in use of public facilities when user fees were removed. The new study adds evidence though that this increase was a result of people switching from private to public providers. In Neno district, Malawi there are no private providers – only those in the study. Nevertheless, private providers also charge, so health care use in the face of fees was markedly higher in Zambia than Neno, Malawi. Perhaps there are relevant differences then in the populations under study.

Zambia, even in 2006, was much wealthier than Malawi in 2013. GDP per capita in comparable dollars was $1,030 in 2006 Zambia and $333 in 2013 Malawi. And Neno district is among the poorest in Malawi. The Malawi study population may be significantly poorer then than that in Zambia, and so have yet more elastic demand. Then again, Zambia is one of the most unequal countries in the world, its wealth generated from a boom in the copper price and other commodities. Its Gini coefficient is 57.5 as compared to Malawi’s 43.9. Thus, one may expect rural Zambians to perhaps be comparable to those in Malawi despite GDP differences. Unfortunately, there aren’t further statistics in the paper to compare the samples – and indeed no information on the relative prices of the user fees. And further, the Zambia paper does look at the poorest 50% of people separately and finds little difference in the treatment effect although there does appear to be large levels of heterogeneity in the estimated treatment effects between districts.

Differences in conclusions may also results from differences in data. For example, the Zambia study looked at changes in the reported use of formal health care among people who had an illness recently, whereas the Malawian study looked at outpatient attendances and diagnoses. Perhaps a difference could arise here such as reporting biases in the survey data.

It is not clear why results in the Zambian study differ from those in the Malawian one and indeed many others. It certainly shows the difficulty we have understanding the effect even small charges can have on access to care even as the quality of the evidence improves.

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Sam Watson’s journal round-up for 7th August 2017

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.

Financing transformative health systems towards achievement of the health Sustainable Development Goals: a model for projected resource needs in 67 low-income and middle-income countries. Lancet: Global Health [PubMedPublished 17th July 2017

Achieving universal health coverage is a key aspect of the UN’s sustainable development goals. However, what this means in practice is complicated. People need to be able to access health services free at the point of use, but once those services are accessed there needs to be sufficient labour, capital, skill, and quality to correctly diagnose and treat them. For many health systems worldwide, this will require large investments in infrastructure and staffing, but the potential cost of achieving these goals is unclear. This article sets out to estimate these costs. Clearly, this is a complicated task – health care systems are incredibly complex. From a basic microeconomic standpoint, one might need some understanding of the production function of different health care systems, and the marginal productivity of labour and capital inputs to these systems. There is generally good evidence of what is effective and cost-effective for the treatment of different diseases, and so given the amenable disease burden for a particular country, we could begin to understand what would be required to combat it. This is how this article tackles this question, more or less. They take a bottom-up costing approach to a wide range of interventions, governance requirements, and, where required, other interventions such as water and sanitation. However, there are other mechanisms at play. At national levels, economies of scale and scope play a role. Integration of care programs can reduce the costs, improve the quality, or both, of the individual programs. Similarly, the levels of investment considered are likely to have relevant macroeconomic effects, boosting employment, income, and subsequent socioeconomic indicators. Credit is due to the authors, they do consider financing and health impacts of investment, and their paper is the most comprehensive to date on the topic. However, their projections (~$300 billion annually) are perhaps more uncertain than they let on, a criticism I made of similar papers recently. While I should remind myself not to let the perfect be the enemy of the good, detailed case studies of particular countries may help me to see how the spreadsheet model may actually translate into real-world changes.

Precommitment, cash transfers, and timely arrival for birth: evidence from a randomized controlled trial in Nairobi Kenya. American Economic Review [RePEcPublished May 2017

A great proportion of the gains in life expectancy in recent years has been through the reduction of childhood mortality. The early years of life are some of the most precarious. A newborn child, if she survives past five years of age, will not face the same risk of dying until late adulthood. Many of the same risk factors that contribute to childhood mortality also contribute to maternal death rates and many low-income countries still face unacceptably high rates of dying for both mother and child. One way of tackling this is to ensure mothers have access to adequate antenatal and postnatal care. In Kenya, for example, the government legislated to provide free delivery services in government health facilities in 2013. However, Kenya still has some of the highest death rates for mother and child in the world. It is speculated that one reason for this is the delay in receiving services in the case of complications with a pregnancy. A potential cause of this delay in Nairobi is a lack of adequate planning from women who face a large number of heterogeneous treatment options for birth. This study presents an RCT in which pregnant women were offered a “precommitment transfer package”, which consisted of a cash transfer of 1000 KSh (~£7) during pregnancy and a further 1000 KSh if women stuck to a delivery plan they had earlier committed to. The transfer was found to increase the proportion of women arriving early to delivery facilities. The study was a fairly small pilot study and the results somewhat uncertain, but the intervention appears promising. Cost-effectiveness comparisons are warranted with other interventions aiming to achieve the same ends.

Bans on electronic cigarette sales to minors and smoking among high school students. Journal of Health Economics [PubMedPublished July 2017

E-cigarettes have provoked quite a debate among public health researchers and campaigners as we’ve previously discussed. E-cigarettes are a substitute for tobacco smoking and are likely to be significantly less harmful. They may have contributed to large declines in the use of tobacco in the UK in the last few years. However, some have taken a “think of the children!” position. While e-cigarette use per se among adolescents may not be a significant public health issue, it could lead to increased use of tobacco. Others have countered that those young people using e-cigarettes would have been those that used tobacco anyway, so banning e-cigarettes among minors may lead them to go back to the tobacco. This paper takes data from repeated surveys of high school students in the US to estimate the effects of banning the sale of e-cigarettes to minors on the prevalence of tobacco smoking. Interestingly, bans appear to reduce tobacco smoking prevalence; the results appear fairly robust and the modelling is sensible. This conflicts with other recent similar studies. The authors argue that this shows that e-cigarettes and tobacco smoking are complements, so reducing one reduces the other. But I am not sure this explains the decline since no increase in youth smoking was observed as e-cigarettes became more popular. Certainly, such a ban would not have reduced smoking prevalence years ago. At the very least e-cigarettes have clearly had a significant effect on attitudes towards smoking. Perhaps smoking was on the decline anyway – but the authors estimate a model with state-specific time trends, and no declines were seen in control states. Whatever our prior beliefs about the efficacy of regulating or banning e-cigarettes, the evidence is complex, reflecting the complex behaviour of people towards drugs, alcohol, and tobacco.

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