David Mott’s journal round-up for 16th September 2019

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.

Opening the ‘black box’: an overview of methods to investigate the decision‑making process in choice‑based surveys. The Patient [PubMed] Published 5th September 2019

Choice-based surveys using methods such as discrete choice experiments (DCEs) and best-worst scaling (BWS) exercises are increasingly being used in health to understand people’s preferences. A lot of time and energy is spent on analysing the data that come out from these surveys but increasingly there is an interest in better understanding respondents’ decision-making processes. Whilst many will be aware of ‘think aloud’ interviews (often used for piloting), other methods may be less familiar as they’re not applied frequently in health. That’s where this fascinating paper by Dan Rigby and colleagues comes in. It provides an overview of five different methods of what they call ‘pre-choice process analysis’ of decision-making, describing the application, state of knowledge, and future research opportunities.

Eye-tracking has been used in health recently. It’s intuitive and provides an insight into where the participants’ focus is (or isn’t). The authors explained that one of the ways it has been used is to explore attribute non-attendance (ANA), which essentially occurs when people are ignoring attributes either because they’re irrelevant to them, or simply because it makes the task easier. However, surprisingly, it has been suggested that ‘visual ANA’ (not looking at the attribute) doesn’t always align with ‘stated ANA’ (participants stating that they ignored the attribute) – which raises some interesting questions!

However, the real highlight for me was the overview of the use of brain imaging techniques to explore choices being made in DCEs. One study highlighted by the authors – which was a DCE about eggs and is now at least #2 on my list of the bizarre preference study topics after this oddly specific one on Iberian ham – predicted choices from an initial ‘passive viewing’ using functional magnetic resonance imaging (fMRI). They found that incorporating changes in blood flow (prompted by changes in attribute levels during ‘passive viewing’) into a random utility model accounted for a lot of the variation in willingness to pay for eggs – pretty amazing stuff.

Whilst I’ve highlighted the more unusual methods here, after reading this overview I have to admit that I’m an even bigger advocate for the ‘think aloud’ technique now. Although it may have some limitations, the amount of insight offered combined with its practicality is hard to beat. Though maybe I’m biased because I know that I won’t get my hands on any eye-tracking or brain imaging devices any time soon. In any case, I highly recommend that any researchers conducting preference studies give this paper a read as it’s really well written and will surely be of interest.

Disentangling public preferences for health gains at end-of-life: further evidence of no support of an end-of-life premium. Social Science & Medicine [PubMed] Published 21st June 2019

The end of life (EOL) policy introduced by NICE in 2009 [PDF] has proven controversial. The policy allows treatments that are not cost-effective within the usual range to be considered for approval, provided that certain criteria are met. Specifically, that the treatment targets patients with a short life expectancy (≤24 months), offers a life extension (of ≥3 months) and is for a ‘small patient population’. One of the biggest issues with this policy is that it is unclear whether the general population actually supports the idea of valuing health gains (specifically life extension) at EOL more than other health gains.

Numerous academic studies, usually involving some form of stated preference exercise, have been conducted to test whether the public might support this EOL premium. A recent review by Koonal Shah and colleagues summarised the existing published studies (up to October 2017), highlighting that evidence is extremely mixed. This recently published Danish study, by Lise Desireé Hansen and Trine Kjær, adds to this literature. The authors conducted an incredibly thorough stated preference exercise to test whether quality of life (QOL) gains and life extension (LE) at EOL are valued differently from other similarly sized health gains. Not only that, but the study also explored the effect of perspective on results (social vs individual), the effect of age (18-35 vs. 65+), and impact of initial severity (25% vs. 40% initial QOL) on results.

Overall, they did not find evidence of support for an EOL premium for QOL gains or for LEs (regardless of perspective) but their results do suggest that QOL gains are preferred over LE. In some scenarios, there was slightly more support for EOL in the social perspective variant, relative to the individual perspective – which seems quite intuitive. Both age and initial severity had an impact on results, with respondents preferring to treat the young and those with worse QOL at baseline. One of the most interesting results for me was within their subgroup analyses, which suggested that women and those with a relation to a terminally ill patient had a significantly positive preference for EOL – but only in the social perspective scenarios.

This is a really well-designed study, which covers a lot of different concepts. This probably doesn’t end the debate on NICE’s use of the EOL criteria – not least because the study wasn’t conducted in England and Wales – but it contributes a lot. I’d consider it a must-read for anyone interested in this area.

How should we capture health state utility in dementia? Comparisons of DEMQOL-Proxy-U and of self- and proxy-completed EQ-5D-5L. Value in Health Published 26th August 2019

Capturing quality of life (QOL) in dementia and obtaining health state utilities is incredibly challenging; which is something that I’ve started to really appreciate recently upon getting involved in a EuroQol-funded ‘bolt-ons’ project. The EQ-5D is not always able to detect meaningful changes in cognitive function and condition-specific preference-based measures (PBMs), such as the DEMQOL, may be preferred as a result. However, this isn’t the only challenge because in many cases patients are not in a position to complete the surveys themselves. This means that proxy-reporting is often required, which could be done by either a professional (formal) carer, or a friend or family member (informal carer). Researchers that want to use a PBM in this population therefore have a lot to consider.

This paper compares the performance of the EQ-5D-5L and the DEMQOL-Proxy when completed by care home residents (EQ-5D-5L only), formal carers and informal carers. The impressive dataset that the authors use contains 1,004 care home residents, across up to three waves, and includes a battery of different cognitive and QOL measures. The overall objective was to compare the performance of the EQ-5D-5L and DEMQOL-Proxy, across the three respondent groups, based on 1) construct validity, 2) criterion validity, and 3) responsiveness.

The authors found that self-reported EQ-5D-5L scores were larger and less responsive to changes in the cognitive measures, but better at capturing residents’ self-reported QOL (based on a non-PBM) relative to proxy-reported scores. It is unclear whether this is a case of adaptation as seen in many other patient groups, or if the residents’ cognitive impairments prevent them from reliably assessing their current status. The proxy-reported EQ-5D-5L scores were generally more responsive to changes in the cognitive measures relative to the DEMQOL-Proxy (irrespective of which type of proxy), which the authors note is probably due to the fact that the DEMQOL-Proxy focuses more on the emotional impact of dementia rather than functional impairment.

Overall, this is a really interesting paper, which highlights the challenges well and illustrates that there is value in collecting these data from both patients and proxies. In terms of the PBM comparison, whilst the authors do not explicitly state it, it does seem that the EQ-5D-5L may have a slight upper hand due to its responsiveness, as well as for pragmatic reasons (the DEMQOL-Proxy has >30 questions). Perhaps a cognition ‘bolt-on’ to the EQ-5D-5L might help to improve the situation in future?

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Meeting round-up: iHEA Congress 2019

Missed iHEA 2019? Or were you there but could not make it to all of the amazing sessions? Stay tuned for my conference highlights!

iHEA started on Saturday 13th with pre-congress sessions on fascinating research as well as more prosaic topics, such as early-career networking sessions with senior health economists. All attendees got a super useful plastic bottle – great idea iHEA team!

The conference proper launched on Sunday evening with the brilliant plenary session by Raj Chetty from Harvard University.

Monday morning started bright and early with the thought-provoking session on validation of CE models. It was chaired and discussed by Stefan Lhachimi and featured presentations by Isaac Corro Ramos, Talitha Feenstra and Salah Ghabri. I’m pleased to see that validation is coming to the forefront of current topics! Clearly, we need to do better in validating our models and documenting code, but we’re on the right track and engaged in making this happen.

Next up, the superb session on the societal perspective for cost-effectiveness analysis. It was an all-star cast with Mark Sculpher, Simon Walker, Susan Griffin, Peter Neumann, Lisa Robinson, and Werner Brouwer. I’ve live-tweeted it here.

The case was expertly made that taking a single sector perspective can be misleading when evaluating policies with cross-sectoral effects, hence the impact inventory by Simon and colleagues is a useful tool to guide the choice of sectors to include. At the same time, we should be mindful of the requirements of the decision-maker for whom CEA is intended. This was a compelling session, which will definitely set the scene for much more research to come.

After a tasty lunch (well done catering team!), I headed to the session on evaluations using non-randomised data. The presenters included Maninie Molatseli, Fernando Antonio Postali, James Love-Koh and Taufik Hidayat, on case studies from South Africa, Brazil and Indonesia. Marc Suhrcke chaired. I really enjoyed hearing about the practicalities of applying econometric methods to estimate treatment effects of system wide policies. And James’s presentation was a great application of distributional cost-effectiveness analysis.

I was on the presenter’s chair next, discussing the challenges in implementing policies in the southwest quadrant of the CE plane. This session was chaired by Anna Vassall and discussed by Gesine Meyer-Rath. Jack Dowie started by convincingly arguing that the decision rule should be the same regardless of where in the CE plane the policy falls. David Bath and Sergio Torres-Rueda presented fascinating case studies of south west policies. And I argued that the barrier was essentially a problem of communication (presentation available here). An energetic discussion followed and showed that, even in our field, the matter is far from settled.

The day finished with the memorial session for the wonderful Alan Maynard and Uwe Reinhardt, both of whom did so much for health economics. It was a beautiful session, where people got together to share incredible stories from these health economics heroes. And if you’d like to know more, both Alan and Uwe have published books here and here.

Tuesday started with the session on precision medicine, chaired by Dean Regier, and featuring Rosalie Viney, Chris McCabe and Stuart Peacock. Rather than slides, the screen was filled with a video of a cosy fireplace, inviting the audience to take part in the discussion.

Under debate was whether precision medicine is a completely different type of technology, with added benefits over and above improvement to health, and needing a different CE framework. The panellists were absolutely outstanding in debating the issues! Although I understand the benefits beyond health that these technologies can offer, I side with the view that, like with other technologies, value is about whether the added benefits are worth the losses given the opportunity cost.

My final session of the day was by the great Mike Drummond, comparing how HTA has influenced the uptake of new anticancer drugs in Spain versus England (summary in thread below). Mike and colleagues found that positive recommendations do increase utilisation, but the magnitude of change differs by country and region. The work is ongoing in checking that utilisation has been picked up accurately in the routine data sources.

The conference dinner was at the Markthalle, with plenty of drinks and loads of international food to choose from. I had to have an early night given that I was presenting at 8:30 the next morning. Others, though, enjoyed the party until the early hours!

Indeed, Wednesday started with my session on cost-effectiveness analysis of diagnostic tests. Alison Smith presented on her remarkable work on measurement uncertainty while Hayley Jones gave a masterclass on her new method for meta-analysis of test accuracy across multiple thresholds. I presented on the CEA of test sequences (available here). Simon Walker and James Buchanan added insightful points as discussants. We had a fantastically engaged audience, with great questions and comments. It shows that the CEA of diagnostic tests is becoming a hugely important topic.

Sadly, some other morning sessions were not as well attended. One session, also on CEA, was even cancelled due to lack of audience! For future conferences, I’d suggest scheduling the sessions on the day after the conference dinner a bit later, as well as having fewer sessions to choose from.

Next up on my agenda was the exceptional session on equity, chaired by Paula Lorgelly, and with presentations by Richard Cookson, Susan Griffin and Ijeoma Edoka. I was unable to attend, but I have watched it at home via YouTube (from 1:57:10)! That’s right, some sessions were live streamed and are still available via the iHEA website. Do have a look!

My last session of the conference was on end-of-life care, with Charles Normand chairing, discussed by Helen Mason, Eric Finkelstein, and Mendwas Dzingina, and presentations by Koonal Shah, Bridget Johnson and Nikki McCaffrey. It was a really thought-provoking session, raising questions on the value of interventions at the end-of-life compared to at other stages of the life course.

Lastly, the outstanding plenary session by Lise Rochaix and Joseph Kutzin on how to translate health economics research into policy. Lise and Joseph had pragmatic suggestions and insightful comments on the communication of health economics research to policy makers. Superb! Also available on the live stream here (from 06:09:44).

iHEA 2019 was truly an amazing conference. Expertly organised, well thought-out and with lots of interesting sessions to choose from. iHEA 2021 in Cape Town is firmly in my diary!

Chris Sampson’s journal round-up for 11th 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.

End-of-life healthcare expenditure: testing economic explanations using a discrete choice experiment. Journal of Health Economics Published 7th June 2018

People incur a lot of health care costs at the end of life, despite the fact that – by definition – they aren’t going to get much value from it (so long as we’re using QALYs, anyway). In a 2007 paper, Gary Becker and colleagues put forward a theory for the high value of life and high expenditure on health care at the end of life. This article sets out to test a set of hypotheses derived from this theory, namely: i) higher willingness-to-pay (WTP) for health care with proximity to death, ii) higher WTP with greater chance of survival, iii) societal WTP exceeds individual WTP due to altruism, and iv) societal WTP may exceed individual WTP due to an aversion to restricting access to new end-of-life care. A further set of hypotheses relating to the ‘pain of risk-bearing’ is also tested. The authors conducted an online discrete choice experiment (DCE) with 1,529 Swiss residents, which asked respondents to suppose that they had terminal cancer and was designed to elicit WTP for a life-prolonging novel cancer drug. Attributes in the DCE included survival, quality of life, and ‘hope’ (chance of being cured). Individual WTP – using out-of-pocket costs – and societal WTP – based on social health insurance – were both estimated. The overall finding is that the hypotheses are on the whole true, at least in part. But the fact is that different people have different preferences – the authors note that “preferences with regard to end-of-life treatment are very heterogeneous”. The findings provide evidence to explain the prevailing high level of expenditure in end of life (cancer) care. But the questions remain of what we can or should do about it, if anything.

Valuation of preference-based measures: can existing preference data be used to generate better estimates? Health and Quality of Life Outcomes [PubMed] Published 5th June 2018

The EuroQol website lists EQ-5D-3L valuation studies for 27 countries. As the EQ-5D-5L comes into use, we’re going to see a lot of new valuation studies in the pipeline. But what if we could use data from one country’s valuation to inform another’s? The idea is that a valuation study in one country may be able to ‘borrow strength’ from another country’s valuation data. The author of this article has developed a Bayesian non-parametric model to achieve this and has previously applied it to UK and US EQ-5D valuations. But what about situations in which few data are available in the country of interest, and where the country’s cultural characteristics are substantially different. This study reports on an analysis to generate an SF-6D value set for Hong Kong, firstly using the Hong Kong values only, and secondly using the UK value set as a prior. As expected, the model which uses the UK data provided better predictions. And some of the differences in the valuation of health states are quite substantial (i.e. more than 0.1). Clearly, this could be a useful methodology, especially for small countries. But more research is needed into the implications of adopting the approach more widely.

Can a smoking ban save your heart? Health Economics [PubMed] Published 4th June 2018

Here we have another Swiss study, relating to the country’s public-place smoking bans. Exposure to tobacco smoke can have an acute and rapid impact on health to the extent that we would expect an immediate reduction in the risk of acute myocardial infarction (AMI) if a smoking ban reduces the number of people exposed. Studies have already looked at this effect, and found it to be large, but mostly with simple pre-/post- designs that don’t consider important confounding factors or prevailing trends. This study tests the hypothesis in a quasi-experimental setting, taking advantage of the fact that the 26 Swiss cantons implemented smoking bans at different times between 2007 and 2010. The authors analyse individual-level data from Swiss hospitals, estimating the impact of the smoking ban on AMI incidence, with area and time fixed effects, area-specific time trends, and unemployment. The findings show a large and robust effect of the smoking ban(s) for men, with a reduction in AMI incidence of about 11%. For women, the effect is weaker, with an average reduction of around 2%. The evidence also shows that men in low-education regions experienced the greatest benefit. What makes this an especially nice paper is that the authors bring in other data sources to help explain their findings. Panel survey data are used to demonstrate that non-smokers are likely to be the group benefitting most from smoking bans and that people working in public places and people with less education are most exposed to environmental tobacco smoke. These findings might not be generalisable to other settings. Other countries implemented more gradual policy changes and Switzerland had a particularly high baseline smoking rate. But the findings suggest that smoking bans are associated with population health benefits (and the associated cost savings) and could also help tackle health inequalities.

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