Sam Watson’s journal round-up for 25th June 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.

The efficiency of slacking off: evidence from the emergency department. Econometrica [RePEc] Published May 2018

Scheduling workers is a complex task, especially in large organisations such as hospitals. Not only should one consider when different shifts start throughout the day, but also how work is divided up over the course of each shift. Physicians, like anyone else, value their leisure time and want to go home at the end of a shift. Given how they value this leisure time, as the end of a shift approaches physicians may behave differently. This paper explores how doctors in an emergency department behave at ‘end of shift’, in particular looking at whether doctors ‘slack off’ by accepting fewer patients or tasks and also whether they rush to finish those tasks they have. Both cases can introduce inefficiency by either under-using their labour time or using resources too intensively to complete something. Immediately, from the plots of the raw data, it is possible to see a drop in patients ‘accepted’ both close to end of shift and close to the next shift beginning (if there is shift overlap). Most interestingly, after controlling for patient characteristics, time of day, and day of week, there is a decrease in the length of stay of patients accepted closer to the end of shift, which is ‘dose-dependent’ on time to end of shift. There are also marked increases in patient costs, orders, and inpatient admissions in the final hour of the shift. Assuming that only the number of patients assigned and not the type of patient changes over the course of a shift (a somewhat strong assumption despite the additional tests), then this would suggest that doctors are rushing care and potentially providing sub-optimal or inefficient care closer to the end of their shift. The paper goes on to explore optimal scheduling on the basis of the results, among other things, but ultimately shows an interesting, if not unexpected, pattern of physician behaviour. The results relate mainly to efficiency, but it’d be interesting to see how they relate to quality in the form of preventable errors.

Semiparametric estimation of longitudinal medical cost trajectory. Journal of the American Statistical Association Published 19th June 2018

Modern computational and statistical methods have opened up a range of statistical models to estimation hitherto inestimable. This includes complex latent variable structures, non-linear models, and non- and semi-parametric models. Recently we covered the use of splines for semi-parametric modelling in our Method of the Month series. Not that complexity is everything of course, but given this rich toolbox to more faithfully replicate the data generating process, one does wonder why the humble linear model estimated with OLS remains so common. Nevertheless, I digress. This paper addresses the problem of estimating the medical cost trajectory for a given disease from diagnosis to death. There are two key issues: (i) the trajectory is likely to be non-linear with costs probably increasing near death and possibly also be higher immediately after diagnosis (a U-shape), and (ii) we don’t observe the costs of those who die, i.e. there is right-censoring. Such a set-up is also applicable in other cases, for example looking at health outcomes in panel data with informative dropout. The authors model medical costs for each month post-diagnosis and time of censoring (death) by factorising their joint distribution into a marginal model for censoring and a conditional model for medical costs given the censoring time. The likelihood then has contributions from the observed medical costs and their times, and the times of the censored outcomes. We then just need to specify the individual models. For medical costs, they use a multivariate normal with mean function consisting of a bivariate spline of time and time of censoring. The time of censoring is modelled non-parametrically. This setup of the missing data problem is sometimes referred to as a pattern mixing model, in that the outcome is modelled as a mixture density over different populations dying at different times. The authors note another possibility for informative missing data, which was considered not to be estimable for complex non-linear structures, was the shared parameter model (to soon appear in another Method of the Month) that assumes outcomes and dropout are independent conditional on an underlying latent variable. This approach can be more flexible, especially in cases with varying treatment effects. One wonders if the mixed model representation of penalised splines wouldn’t fit nicely in a shared parameter framework and provide at least as good inferences. An idea for a future paper perhaps… Nevertheless, the authors illustrate their method by replicating the well-documented U-shaped costs from the time of diagnosis in patients with stage IV breast cancer.

Do environmental factors drive obesity? Evidence from international graduate students. Health Economics [PubMedPublished 21st June 2018

‘The environment’ can encompass any number of things including social interactions and networks, politics, green space, and pollution. Sometimes referred to as ‘neighbourhood effects’, the impact of the shared environment above and beyond the effect of individual risk factors is of great interest to researchers and policymakers alike. But there are a number of substantive issues that hinder estimation of neighbourhood effects. For example, social stratification into neighbourhoods likely means people living together are similar so it is difficult to compare like with like across neighbourhoods; trying to model neighbourhood choice will also, therefore, remove most of the variation in the data. Similarly, this lack of common support, i.e. overlap, between people from different neighbourhoods means estimated effects are not generalisable across the population. One way of getting around these problems is simply to randomise people to neighbourhoods. As odd as that sounds, that is what occurred in the Moving to Opportunity experiments and others. This paper takes a similar approach in trying to look at neighbourhood effects on the risk of obesity by looking at the effects of international students moving to different locales with different local obesity rates. The key identifying assumption is that the choice to move to different places is conditionally independent of the local obesity rate. This doesn’t seem a strong assumption – I’ve never heard a prospective student ask about the weight of our student body. Some analysis supports this claim. The raw data and some further modelling show a pretty strong and robust relationship between local obesity rates and weight gain of the international students. Given the complexity of the causes and correlates of obesity (see the crazy diagram in this post) it is hard to discern why certain environments contribute to obesity. The paper presents some weak evidence of differences in unhealthy behaviours between high and low obesity places – but this doesn’t quite get at the environmental link, such as whether these behaviours are shared through social networks or perhaps the structure and layout of the urban area, for example. Nevertheless, here is some strong evidence that living in an area where there are obese people means you’re more likely to become obese yourself.

Credits

Alastair Canaway’s journal round-up for 28th May 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.

Information, education, and health behaviours: evidence from the MMR vaccine autism controversy. Health Economics [PubMed] Published 2nd May 2018

In 1998, Andrew Wakefield published (in the Lancet) his infamous and later retracted research purportedly linking the measles-mumps-rubella (MMR) vaccine and autism. Despite the thorough debunking and exposure of academic skulduggery, a noxious cloud of misinformation remained in the public mind, particularly in the US. This study examined several facets of the MMR fake news including: what impact did this have on vaccine uptake in the US (both MMR and other vaccines); how did state level variation in media coverage impact uptake; and what role did education play in subsequent decisions about whether to vaccinate or not. This study harnessed the National Immunization Survey from 1995 to 2006 to answer these questions. This is a yearly dataset of over 200,000 children aged between 19 to 35 months with detailed information on not just immunisation, but also maternal education, income and other sociodemographics. The NewsLibrary database was used to identify stories published in national and state media relating to vaccines and autism. Various regression methods were implemented to examine these data. The paper found that, unsurprisingly, for the year following the Wakefield publication the MMR vaccine take-up declined by between 1.1%-1.5% (notably less than 3% in the UK), likewise this fall in take-up spilled over into other vaccines take-up. The most interesting finding related to education: MMR take-up for children of college-educated mothers declined significantly compared to those without a degree. This can be explained by the education gradient where more-educated individuals absorb and respond to health information more quickly. However, in the US, this continued for many years beyond 2003 despite proliferation of research refuting the autism-MMR link. This contrasts to the UK where educational link closed soon after the findings were refuted, that is, in the UK, the educated responded to the new information refuting the MMR-Autism link. In the US, despite the research being debunked, MMR uptake was lower in the children of those with higher levels of education for many more years. The author speculates that this contrast to the UK may be a result of the media influencing parents’ decisions. Whilst the media buzz in the UK peaked in 2002, it had largely subsided by 2003. In the US however, the media attention was constant, if not increasing till 2006, and so this may have been the reason the link remained within the US. So, we have Andrew Wakefield and arguably fearmongering media to blame for causing a long-term reduction in MMR take-up in the US. Overall, an interesting study leaning on multiple datasets that could be of interest for those working with big data.

Can social care needs and well-being be explained by the EQ-5D? Analysis of the Health Survey for England. Value in Health Published 23rd May 2018

There is increasing discussion about integrating health and social care to provide a more integrated approach to fulfilling health and social care needs. This creates challenges for health economists and decision makers when allocating resources, particularly when comparing benefits from different sectors. NICE itself recognises that the EQ-5D may be inappropriate in some situations. With the likes of ASCOT, ICECAP and WEMWBS frequenting the health economics world this isn’t an unknown issue. To better understand the relationship between health and social care measures, this EuroQol Foundation funded study examined the relationship between social care needs as measured by the Barthel Index, well-being measured using WEMWBS and also the GGH-12, and the EQ-5D as the measure of health. Data was obtained through the Health Survey for England (HSE) and contained 3354 individuals aged over 65 years. Unsurprisingly the authors found that higher health and wellbeing scores were associated with an increased probability of no social care needs. Those who are healthier or at higher levels of wellbeing are less likely to need social care. Of all the instruments, it was the self-care and the pain/discomfort dimensions of the EQ-5D that were most strongly associated with the need for social care. No GHQ-12 dimensions were statistically significant, and for the WEMWBS only the ‘been feeling useful’ and ‘had energy to spare’ were statistically significantly associated with social care need. The authors also investigated various other associations between the measures with many unsurprising findings e.g. EQ-5D anxiety/depression dimension was negatively associated with wellbeing as measured using the GHQ-12. Although the findings are favourable for the EQ-5D in terms of it capturing to some extent social care needs, there is clearly still a gap whereby some outcomes are not necessarily captured. Considering this, the authors suggest that it might be appropriate to strap on an extra dimension to the EQ-5D (known as a ‘bolt on’) to better capture important ‘other’ dimensions, for example, to capture dignity or any other important social care outcomes. Of course, a significant limitation with this paper relates to the measures available in the data. Measures such as ASCOT and ICECAP have been developed and operationalised for economic evaluation with social care in mind, and a comparison against these would have been more informative.

The health benefits of a targeted cash transfer: the UK Winter Fuel Payment. Health Economics [PubMed] [RePEc] Published 9th May 2018

In the UK, each winter is accompanied by an increase in mortality, often known as ‘excess winter mortality’ (EWM). To combat this, the UK introduced the Winter Fuel Payment (WFP), the purpose of the WFP is an unconditional cash transfer to households containing an older person (those most vulnerable to EWM) above the female state pension age with the intent for this to used to help the elderly deal with the cost of keeping their dwelling warm. The purpose of this paper was to examine whether the WFP policy has improved the health of elderly people. The authors use the Health Surveys for England (HSE), the Scottish health Survey (SHeS) and the English Longitudinal Study of Ageing (ELSA) and employ a regression discontinuity design to estimate causal effects of the WFP. To measure impact (benefit) they focus on circulatory and respiratory illness as measured by: self-reports of chest infection, nurse measured hypertension, and two blood biomarkers for infection and inflammation. The authors found that for those living in a household receiving the payment there was a 6% point reduction (p<0.01) in the incidence of high levels of serum fibrinogen (biomarker) which are considered to be a marker of current infection and are associated with chronic pulmonary disease. For the other health outcomes, although positive, the estimated effects were less robust and not statistically significant. The authors investigated the impact of increasing the age of eligibility for the WFP (in line with the increase of women’s pension age). Their findings suggest there may be some health cost associated with the increase in age of eligibility for WFP. To surmise, the paper highlights that there may be some health benefits from the receipt of the WFP. What it doesn’t however consider is opportunity cost. With WFP costing about £2 billion per year, as a health economist, I can’t help but wonder if the money could have been better spent through other avenues.

Credits

 

Chris Sampson’s journal round-up for 19th March 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.

Using HTA and guideline development as a tool for research priority setting the NICE way: reducing research waste by identifying the right research to fund. BMJ Open [PubMed] Published 8th March 2018

As well as the cost-effectiveness of health care, economists are increasingly concerned with the cost-effectiveness of health research. This makes sense, given that both are usually publicly funded and so spending on one (in principle) limits spending on the other. NICE exists in part to prevent waste in the provision of health care – seeking to maximise benefit. In this paper, the authors (all current or ex-employees of NICE) consider the extent to which NICE processes are also be used to prevent waste in health research. The study focuses on the processes underlying NICE guideline development and HTA, and the work by NICE’s Science Policy and Research (SP&R) programme. Through systematic review and (sometimes) economic modelling, NICE guidelines identify research needs, and NICE works with the National Institute for Health Research to get their recommended research commissioned, with some research fast-tracked as ‘NICE Key Priorities’. Sometimes, it’s also necessary to prioritise research into methodological development, and NICE have conducted reviews to address this, with the Internal Research Advisory Group established to ensure that methodological research is commissioned. The paper also highlights the roles of other groups such as the Decision Support Unit, Technical Support Unit and External Assessment Centres. This paper is useful for two reasons. First, it gives a clear and concise explanation of NICE’s processes with respect to research prioritisation, and maps out the working groups involved. This will provide researchers with an understanding of how their work fits into this process. Second, the paper highlights NICE’s current research priorities and provides insight into how these develop. This could be helpful to researchers looking to develop new ideas and proposals that will align with NICE’s priorities.

The impact of the minimum wage on health. International Journal of Health Economics and Management [PubMed] Published 7th March 2018

The minimum wage is one of those policies that is so far-reaching, and with such ambiguous implications for different people, that research into its impact can deliver dramatically different conclusions. This study uses American data and takes advantage of the fact that different states have different minimum wage levels. The authors try to look at a broad range of mechanisms by which minimum wage can affect health. A major focus is on risky health behaviours. The study uses data from the Behavioral Risk Factor Surveillance System, which includes around 300,000 respondents per year across all states. Relevant variables from these data characterise smoking, drinking, and fruit and vegetable consumption, as well as obesity. There are also indicators of health care access and self-reported health. The authors cut their sample to include 21-64-year-olds with no more than a high school degree. Difference-in-differences are estimated by OLS according to individual states’ minimum wage changes. As is often the case for minimum wage studies, the authors find several non-significant effects: smoking and drinking don’t seem to be affected. Similarly, there isn’t much of an impact on health care access. There seems to be a small positive impact of minimum wage on the likelihood of being obese, but no impact on BMI. I’m not sure how to interpret that, but there is also evidence that a minimum wage increase leads to a reduction in fruit and vegetable consumption, which adds credence to the obesity finding. The results also demonstrate that a minimum wage increase can reduce the number of days that people report to be in poor health. But generally – on aggregate – there isn’t much going on at all. So the authors look at subgroups. Smoking is found to increase (and BMI decrease) with minimum wage for younger non-married white males. Obesity is more likely to be increased by minimum wage hikes for people who are white or married, and especially for those in older age groups. Women seem to benefit from fewer days with mental health problems. The main concerns identified in this paper are that minimum wage increases could increase smoking in young men and could reduce fruit and veg consumption. But I don’t think we should overstate it. There’s a lot going on in the data, and though the authors do a good job of trying to identify the effects, other explanations can’t be excluded. Minimum wage increases probably don’t have a major direct impact on health behaviours – positive or negative – but policymakers should take note of the potential value in providing public health interventions to those groups of people who are likely to be affected by the minimum wage.

Aligning policy objectives and payment design in palliative care. BMC Palliative Care [PubMed] Published 7th March 2018

Health care at the end of life – including palliative care – presents challenges in evaluation. The focus is on improving patients’ quality of life, but it’s also about satisfying preferences for processes of care, the experiences of carers, and providing a ‘good death’. And partly because these things can be difficult to measure, it can be difficult to design payment mechanisms to achieve desirable outcomes. Perhaps that’s why there is no current standard approach to funding for palliative care, with a lot of variation between countries, despite the common aspiration for universality. This paper tackles the question of payment design with a discussion of the literature. Traditionally, palliative care has been funded by block payments, per diems, or fee-for-service. The author starts with the acknowledgement that there are two challenges to ensuring value for money in palliative care: moral hazard and adverse selection. Providers may over-supply because of fee-for-service funding arrangements, or they may ‘cream-skim’ patients. Adverse selection may arise in an insurance-based system, with demand from high-risk people causing the market to fail. These problems could potentially be solved by capitation-based payments and risk adjustment. The market could also be warped by blunt eligibility restrictions and funding caps. Another difficulty is the challenge of achieving allocative efficiency between home-based and hospital-based services, made plain by the fact that, in many countries, a majority of people die in hospital despite a preference for dying at home. The author describes developments (particularly in Australia) in activity-based funding for palliative care. An interesting proposal – though not discussed in enough detail – is that payments could be made for each death (per mortems?). Capitation-based payment models are considered and the extent to which pay-for-performance could be incorporated is also discussed – the latter being potentially important in achieving those process outcomes that matter so much in palliative care. Yet another challenge is the question of when palliative care should come into play, because, in some cases, it’s a matter of sooner being better, because the provision of palliative care can give rise to less costly and more preferred treatment pathways. Thus, palliative care funding models will have implications for the funding of acute care. Throughout, the paper includes examples from different countries, along with a wealth of references to dig into. Helpfully, the author explicitly states in a table the models that different settings ought to adopt, given their prevailing model. As our population ages and the purse strings tighten, this is a discussion we can expect to be having more and more.

Credits