Chris Sampson’s journal round-up for 13th March 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.

The effects of exercise and relaxation on health and wellbeing. Health Economics [PubMedPublished 9th Month 2017

Encouraging self-management of health sounds like a good idea, but the evidence is pretty weak. As economists, we know that something must be displaced in order to do it. This study considers the opportunity cost of time and how it might affect self-management activity and any associated benefits. Employment and education are likely to increase income and thus facilitate more expenditure on exercise. But the time cost of exercise is also likely to increase, meaning that the impact on demand is ambiguous. The study uses data from a trial of self-management support that included people with diabetes, COPD or IBS. EQ-5D, self-assessed health and the amount of time spent ‘being happy’ were all collected. Information was available for 12 different self-management activities, including ‘do exercises’ and ‘rest and relax’, and the extent to which individuals did these. Outcomes for 3,472 people at 12-month follow-up are estimated, controlling for outcomes at baseline and 6 months. The study assumes that employment and education affect health via their influence on exercise and relaxation. That seems a bit questionable and the other 10 self-management indicators could have been looked at to test this. People in full-time employment were 11 percentage points less likely to use relaxation to manage their condition, suggesting that the substitution effect on time dominates as the opportunity cost of self-management increases. Having a degree or professional qualification increased the probability of using exercise by 5 percentage points, suggesting that the income effect dominates. Those who are more likely to use either exercise or relaxation are also more likely to do the other. An interesting suggestion is that time preference might explain things here. Those with more education may prefer to exercise (as an investment) than to get the instant gratification of rest and relaxation. It’s important that policy recommendations take into consideration the fact that different groups will respond differently to incentives for self-management, at least partly due to their differing time constraints. The thing I find most interesting is the analysis of the different outcomes (something I’ve worked on). Exercise is found to improve self-assessed health, while relaxation increases happiness. Neither exercise or relaxation had a (statistically significant) effect on EQ-5D. Depending on your perspective, this either suggests that the EQ-5D is failing to identify important changes in broad health-related domains or it means that self-management does not achieve the goals (QALYs to the max) of the health service.

New findings from the time trade-off for income approach to elicit willingness to pay for a quality adjusted life year. The European Journal of Health Economics [PubMedPublished 8th March 2017

The question ‘what is a QALY worth’ could invoke any number of reactions in a health economist, from chin scratching to eye rolling. The perspective that we’re probably most familiar with in the UK is that the value of a QALY is the value of health foregone in order to achieve it (i.e. opportunity cost within the health care perspective). An alternative perspective is that the value of a QALY is the consumption value of health; how much consumption would individuals be willing to give up in order to obtain an additional QALY? This second perspective facilitates a broader societal perspective. It can tell us whether or not the budget is set at an appropriate level, while the health care perspective can only take the budget as given. This study relates mainly to decisions made with the ‘consumption value’ perspective. One approach that has been proposed is to assess willingness to pay for a QALY using a time trade-off exercise that incorporates trade-offs between length and quality of life and income. This study builds on the original work by using a multiplicative utility function to estimate willingness to pay and also bringing in prospect theory to allow for reference dependence and loss aversion. 550 participants were asked to choose between living 10 years in their current health state with their current salary or to live a reduced number of years in their current health state with a luxury income (pre-specified by the participant). Respondents were also asked to make a similar choice, but framed as a loss of income, between living 10 years at a subsistence income or fewer years with their current income. A quality of life trade-off exercise was also conducted, in which people traded reduced health and a lower income. The findings support the predictions of prospect theory. Loss aversion is found to be stronger for duration than for quality of life. Individuals were more willing to sacrifice life years to move from subsistence income to current income than to move from current income to luxury income. The results imply that quality of life and income are closer substitutes than longevity and income. That makes sense, given the all-or-nothing nature of being alive. Crucially, the findings highlight the need to better understand the shape of the underlying lifetime utility function. In all tasks, more than half of respondents were either non-traders or over-traded, indicating a negative willingness to pay. That should give pause for thought when it comes to any aggregation of the results. Willingness to pay studies often throw up more questions than answers. This one does so more than most, particularly about sources of bias in people’s responses. The authors identify plenty of opportunities for future research.

Beyond QALYs: multi-criteria based estimation of maximum willingness to pay for health technologies. The European Journal of Health Economics [PubMed] Published 3rd March 2017

Life is messy. Evaluating things in terms of a single outcome, whether that be QALYs, £££s or whatever, is necessarily simplifying and restrictive. That’s not necessarily a bad thing, but we’d do well to bear it in mind. In this paper, Erik Nord sets out a kind of cost value analysis that does away with QALYs (gasp!). The author starts by outlining some familiar criticisms of the QALY approach, such as its failure to consider the inherent value of life and people’s differing reference points. Generally, I see these as features rather than bugs, and it isn’t QALYs themselves in the crosshairs here so much as cost-per-QALY analysis. The proposed method flips current practice by putting societal preferences about fair and efficient resource allocation before attaching values to the outcomes. As such, it acknowledges the fact that society’s preferences for gains in quality of life differ from those for gains in length of life. For example, society may prefer treating the more severely ill (independent of age) but also exhibit a ‘fair innings’ preference that is related to age. Thus, quality and quantity of life are disaggregated and the QALY is no more. A set of tables is presented that can be read to assess ‘value’ in alternative scenarios, given the assumptions set out in the paper. There is merit in the approach and a lot that I like about the possibilities of its use. But for me, the whole thing was made less attractive by the way it is presented in the paper. The author touts willingness to pay – for quality of life gains and for longevity gains – as the basis for value. Anything that makes resource allocation more dependent on willingness to pay values for things without a price (health, life) is a big no-no for me. But the method doesn’t depend on that. Furthermore, as is so often the case, most of the criticisms within relate to ways of using QALYs, rather than the fundamental basis for their estimation. This only weakens the argument for an alternative. But I can think of plenty of problems with QALYs, some of which might be addressed by this alternative approach. It’s unfortunate that the paper doesn’t outline how these more fundamental problems might be addressed. There may come a day when we do away with QALYs, and we may end up doing something similar to what’s outlined here, but we need to think harder about how this alternative is really better.

Credits

Chris Sampson’s journal round-up for 16th 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.

Higher mortality rates amongst emergency patients admitted to hospital at weekends reflect a lower probability of admission. Journal of Health Services Research & Policy Published 6th May 2016

The ‘weekend effect‘ is the hot topic in health policy in the UK right now. Whether or not it exists, and whether or not it can be corrected by steamrollering junior doctors’ contracts, has major implications for the NHS. In this study the authors used data on 12.7 million A&E attendances and 4.7 million emergency admissions in England in 2013-14. It’s possible to be admitted to hospital via A&E or directly from a community service. A&E is available 24/7, while community services are more limited at the weekend. The analyses mainly use logistic regressions with the usual case-mix adjustments to estimate the probability of death within 30 days. Weekend attendance at A&E was not associated with a significantly higher probability of death than attendance during the week. On Saturday or Sunday, there were 7% fewer admissions via A&E than on weekdays. The number of direct admissions via referral from community services was a whopping 61% lower at weekends. For both groups of people admitted, the mortality rate at the weekend was higher than on weekdays; we see the familiar weekend effect. The 7% difference in A&E admission rates could not be explained by the patient characteristics available in the data, suggesting that a higher admission threshold is used at weekends. There was no weekend effect associated with A&E attendances, which is perhaps what a lot of people have in mind when they think about this issue. Only those admitted at the weekend have a higher mortality rate, and in particular those referred from community services. The implication is that mortality rates hide the true story by combining the number of people dying (the numerator) with the number of people being admitted (the denominator). Increasing the number of doctors available at weekends might increase the number of people being admitted (at great cost) but with no reduction in the number of deaths. Patients who are admitted to hospital at the weekend are a different group of people, and different in a way that has not yet been adequately captured by risk-adjustment.

Ageing, justice and resource allocation. Journal of Medical Ethics [PhilPapers] [PubMedPublished 4th May 2016

People are living longer. This contributes to health care expenditure growth as people require more treatment to keep them alive. In this paper, the author argues that we should not focus only on the role of life-prolonging treatments but also on life-enhancing treatments. How people age and the ways in which the chances of becoming ill vary with age ought to be considered in resource allocation decisions. Social context is important in this respect; for example, the availability of public toilets may influence an older person’s willingness to engage in their usual activities. The arguments presented focus mainly on Norman Daniels’s prudential lifespan approach, which essentially considers whether or not a person would choose to purchase insurance for a particular health problem. We would expect an ageing population to insure more against the health problems of later life, and so proportionally greater resources ought to be allocated to older people. But the paper does not pursuade me that this requires any departure from current practice or thought. When Alan Williams described the fair innings approach to just allocations of resources in old age, he was expressly concerned with the quality of life. I’m not clear on what this paper adds, aside from further criticism of Harris’s view that life-extending treatment should always trump life-enhancing treatment. But I know of nobody who actually supports that view. Nevertheless, it’s an interesting discussion with which I hope health economists will engage.

An elicitation of utility for quality of life under prospect theory. Journal of Health Economics [RePEcPublished 2nd May 2016

Back in 1979, Kahneman and Tversky introduced prospect theory. Simply, this deviation from expected utility theory demonstrates that people value gains and losses from a given reference point differently, and that people’s decisions relate to probabilities in a nonlinear way. One of the key aspects of prospect theory is that it allows for loss aversion, which has been observed in the health context. We may therefore wish to develop methods for the estimation of QALYs that are based on prospect theory. This study demonstrates the limited validity of expected utility in estimating QALYs and shows how to estimate utility using prospect theory. A representative Dutch sample of 500 people was recruited for 2 experiments carried out online. Demographic and health state data were collected and participants were presented with possible gains and losses in quality of life within a 20%-100% interval associated with a specified reference point. Loss aversion was observed in both experiments, with evidence that responses were reference-dependent. Furthermore, there was risk aversion associated with both gains and losses. This undermines expected utility as a reasonable basis on which to estimate QALYs. Furthermore, the study found utility to be concave, such that a loss from 60% to 40% was perceived as smaller than a loss from 40% to 20%. This not only differs from the way in which we estimate QALYs, but also from the nature of prospect theory in the valuation of monetary outcomes. Expect to hear plenty more about PT-QALYs in the future.

Efficiency of health investment: education or intelligence? Health Economics [PubMedPublished 3rd May 2016

People with better education are healthier and live longer. But is this due to their education, or simply due to intelligence? It should go without saying that measuring intelligence, let alone separating it from the effects of education, is not straightforward. This study looks at whether education is associated with a higher efficiency of health investment. Health outcome is measured as survival and health investment as hospitalisation for a given condition. The authors then go on to consider the extent to which any benefit is due to intelligence. The data include 2570 Dutch individuals surveyed in 1952 in their final year of primary school and then followed up again in 1983 and 1993. The sample includes those people with hospitalisation records for 1995-2005 and mortality data for 1995-2011. A structural equation model is estimated to capture the impact of intelligence with the states ‘healthy’, ‘hospitalised’ and ‘dead’. Intelligence is modelled as a latent variable based on an IQ test and a vocabulary test at the age of 12. The analysis treats education choice as exogenous but controls for numerous socioeconomic and school-specific variables. People with higher education were less likely to die after a hospitalisation, though this relationship disappears once intelligence is accounted for. This suggests that the health investment advantage of the better educated is due to intelligence. There are plenty of limitations to the study in terms of the available data, but the findings nevertheless suggest that education per se might not be as beneficial to health as previous studies have shown.