Chris Sampson’s journal round-up for 6th January 2020

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.

Child sleep and mother labour market outcomes. Journal of Health Economics [PubMed] [RePEc] Published January 2020

It’s pretty clear that sleep is important to almost all aspects of our lives and our well-being. So it is perhaps surprising that economists have paid relatively little attention to the ways in which the quality of sleep influences the ‘economic’ aspects of our lives. Part of the explanation might be that almost anything that you can imagine having an effect on your sleep is also likely to be affected by your sleep. Identifying causality is a challenge. This paper shows us how it’s done.

The study is focussed on the relationship between sleep and labour market outcomes in new mothers. There’s good reason to care about new mothers’ sleep because many new mothers report that lack of sleep is a problem and many suffer from mental and physical health problems that might relate to this. But the major benefit to this study is that the context provides a very nice instrument to help identify causality – children’s sleep. The study uses data from the Avon Longitudinal Study of Parents and Children (ALSPAC), which seems like an impressive data set. The study recruited 14,541 pregnant women with due dates between 1991 and 1993, collecting data on mothers’ and children’s sleep quality and mothers’ labour market activity. The authors demonstrate that children’s sleep (in terms of duration and disturbances) affects the amount of sleep that mothers get. No surprise there. They then demonstrate that the amount of sleep that mothers get affects their labour market outcomes, in terms of their likelihood of being in employment, the number of hours they work, and household income. The authors also demonstrate that children’s sleep quality does not have a direct impact on mothers’ labour market outcomes except through its effect on mothers’ sleep. The causal mechanism seems difficult to refute.

Using a two-stage least squares model with a child’s sleep as an instrument for their mother’s sleep, the authors estimate the effect of mothers’ sleep on labour market outcomes. On average, a 30-minute increase in a mother’s sleep duration increases the number of hours she works by 8.3% and increases household income by 3.1%. But the study goes further (much further) by identifying the potential mechanisms for this effect, with numerous exploratory analyses. Less sleep makes mothers more likely to self-report having problems at work. It also makes mothers less likely to work full-time. Going even further, the authors test the impact of the UK Employment Rights Act 1996, which gave mothers the right to request flexible working. The effect of the Act was to reduce the impact of mothers’ sleep duration on labour market outcomes, with a 6 percentage points lower probability that mothers drop out of the labour force.

My only criticism of this paper is that the copy-editing is pretty poor! There are so many things in this study that are interesting in their own right but also signal need for further research. Unsurprisingly, the study identifies gender inequalities. No wonder men’s wages increase while women’s plateau. Personally, I don’t much care about labour market outcomes except insofar as they affect individuals’ well-being. Thanks to the impressive data set, the study can also show that the impact on women’s labour market outcomes is not simply a response to changing priorities with respect to work, implying that it is actually a problem. The study provides a lot of food for thought for policy-makers.

Health years in total: a new health objective function for cost-effectiveness analysis. Value in Health Published 23rd December 2019

It’s common for me to complain about papers on this blog, usually in relation to one of my (many) pet peeves. This paper is in a different category. It’s dangerous. I’m angry.

The authors introduce the concept of ‘health years in total’. It’s a simple idea that involves separating the QA and the LY parts of the QALY in order to make quality of life and life years additive instead of multiplicative. This creates the possibility of attaching value to life years over and above their value in terms of the quality of life that is experienced in them. ‘Health years’ can be generated at a rate of two per year because each life year is worth 1 and that 1 is added to what the authors call a ‘modified QALY’. This ‘modified QALY’ is based on the supposition that the number of life years in its estimation corresponds to the maximum number of life years available under any treatment scenario being considered. So, if treatment A provides 2 life years and treatment B provides 3 life years, you multiply the quality of life value of treatment A by 3 years and then add the number of actual life years (i.e. 2). On the face of it, this is as stupid as it sounds.

So why do it? Well, some people don’t like QALYs. A cabal of organisations, supposedly representing patients, has sought to undermine the use of cost-effectiveness analysis. For whatever reason, they have decided to pursue the argument that the QALY discriminates against people with disabilities, or anybody else who happens to be unwell. Depending on the scenario this is either untrue or patently desirable. But the authors of this paper seem happy to entertain the cabal. The foundation for the development of the ‘health years in total’ framework is explicitly based in the equity arguments forwarded by these groups. It’s designed to be a more meaningful alternative to the ‘equal value of life’ measure; a measure that has been used in the US context, which adds a value of 1 to life years regardless of their quality.

The paper does a nice job of illustrating the ‘health years in total’ approach compared with the QALY approach and the ‘equal value of life’ approach. There’s merit in considering alternatives to the QALY model, and there may be value in an ‘additive’ approach that in some way separates the valuation of life years from the valuation of health states. There may even be some ethical justification for the ‘health years in total’ framework. But, if there is, it isn’t provided by this paper. To frame the QALY as discriminatory in the way that the authors do, describing this feature as a ‘limitation’ of the QALY approach, and to present an alternative with no basis in ethics is, at best, foolish. In practice, the ‘health years in total’ calculation would favour life-extending treatments over those that improve health. There are some organisations with vested interests in this. Expect to see ‘health years in total’ obscuring decision-making in the United States in the near future.

The causal effect of education on chronic health conditions in the UK. Journal of Health Economics Published 23rd December 2019

Since the dawn of health economics, researchers have been interested in the ways in which education and health outcomes depend on one another. People with more education tend to be healthier. But identifying causal relationships in this context is almost impossible. Some studies have claimed that education has a positive (causal) effect on both general and specific health outcomes. But there are just as many studies that show no impact. This study attempts to solve the problem by throwing a lot of data at it.

The authors analyse the impact of two sets of reforms in the UK. First, the raising of the school leaving age in 1972, from 15 to 16 years. Second, the broader set of reforms that were implemented in the 1990s that resulted in a major increase in the number of people entering higher education. The study’s weapon is the Quarterly Labour Force Survey (QLFS), which includes over 5 million observations from 1.5 million people. Part of the challenge of identifying the impact of education on health outcomes is that the effects can be expected to be observed over the long-term and can therefore be obscured by other long-term trends. To address this, the authors limit their analyses to people in narrow age ranges in correspondence with the times of the reforms. Thanks to the size of the data set, they still have more than 350,000 observations for each reform. The QLFS asks people to self-report having any of a set of 17 different chronic health conditions. These can be grouped in a variety of ways, or looked at individually. The analysis uses a regression discontinuity framework to test the impact of raising the school leaving age, with birth date acting as an instrument for the number of years spent in education. The analysis of the second reform is less precise, as there is no single discontinuity, so the model identifies variation between the relevant cohorts over the period. The models are used to test a variety of combinations of the chronic condition indicators.

In short, the study finds that education does not seem to have a causal effect on health, in terms of the number of chronic conditions or the probability of having any chronic condition. But, even with their massive data set, the authors cannot exclude the possibility that education does have an effect on health (whether positive or negative). This non-finding is consistent across both reforms and is robust to various specifications. There is one potentially important exception to this. Diabetes. Looking at the school leaving age reform, an additional year of schooling reduces the likelihood of having diabetes by 3.6 percentage points. Given the potential for diabetes to depend heavily on an individual’s behaviour and choices, this seems to make sense. Kids, stay in school. Just don’t do it for the good of your health.

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Shilpi Swami’s journal round-up for 9th December 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.

Performance of UK National Health Service compared with other high-income countries: observational study. BMJ [PubMed] Published 27th November 2019

Efficiencies and inefficiencies of the NHS in the UK have been debated in recent years. This new study reveals the performance of the NHS compared to other high-income countries, based on observational data, and has already caught a bunch of attention (almost 3,000 tweets and 6 news appearances, since publication)!

The authors presented a descriptive analysis of the UK (England, Scotland, Northern Ireland, and Wales) compared to nine other countries (US, Canada, Germany, Australia, Sweden, France, Denmark, the Netherlands, and Switzerland) based on aggregated recent data from a range of sources (such as OECD, World Bank, the Institute for Health Metrics Evaluation, and Eurostat). Good things first; access to care – a lower proportion of people felt unmet needs owing to costs. The waiting times were comparable across other countries, except for specialist care. The UK performed slightly better on the metric of patient safety. The main challenge, however, is that NHS healthcare spending is lower and has been growing more slowly. This means fewer doctors and nurses, and doctors spending less time with patients. The authors vividly suggest that

“Policy makers should consider how recent changes to nursing bursaries, the weakened pound, and uncertainty about the status of immigrant workers in the light of the Brexit referendum result have influenced these numbers and how to respond to these challenges in the future.”

Understandably comparing healthcare systems across the world is difficult. Including the US in the study, and not including other countries like Spain and Japan, may need more justification or could be a scope of future research.

To be fair, the article is a not-to-miss read. It is an eye-opener for those who think it’s only a (too much) demand-side problem the the NHS is facing and confirms the perspective of those who think it’s a (not enough) supply-side problem. Kudos to the hardworking doctors and nurses who are currently delivering efficiently in the stretched situation! For sustainability, the NHS needs to consider increasing its spending to increase labour supply and long-term care.

A systematic review of methods to predict weight trajectories in health economic models of behavioral weight management programs: the potential role of psychosocial factors. Medical Decision Making [PubMed] Published 2nd December 2019

In economic modelling, assumptions are often made about the long-term impact of interventions, and it’s important that these assumptions are based on sound evidence and/or tested in sensitivity analysis, as these could affect the cost-effectiveness results.

The authors explored assumptions about weight trajectories to inform economic modelling of behavioural weight management programmes. Also, they checked their evidence sources, and whether these assumptions were based on any psychosocial variables (such as self-regulation, motivation, self-efficacy, and habit), as these are known to be associated with weight-loss trajectories.

The authors conducted a systematic literature review of economic models of weight management interventions that aimed at reducing weight. In the 38 studies included, they found 6 types of assumptions of weight trajectories beyond trial duration (weight loss maintained, weight loss regained immediately, linear weight regain, subgroup-specific trajectories, exponential decay of effect, maintenance followed by regain), with only 15 of the studies reporting sources for these assumptions. The authors also elaborated on the assumptions and graphically represented them. Psychosocial variables were, in fact, measured in evidence sources of some of the included studies. However, the authors found that none of the studies estimated their weight trajectory assumptions based on these! Though the article also reports on how the assumptions were tested in sensitivity analyses and their impact on results in the studies (if reported within these studies), it would have been interesting to see more insights into this. The authors feel that there’s a need to investigate how psychosocial variables measured in trials can be used within health economic models to calculate weight trajectories and, thus, to improve the validity of cost-effectiveness estimates.

To me, given that only around half of included studies reported sources of assumptions on long-term effects of the interventions and performed sensitivity analysis on these assumptions, it raises the bigger long-debated question on the quality of economic evaluations! To conclude, the review is comprehensive and insightful. It is an interesting read and will be especially useful for those interested in modelling long-term impacts of behavioural support programs.

The societal monetary value of a QALY associated with EQ‐5D‐3L health gains. The European Journal of Health Economics [PubMed] Published 28th November 2019

Finding an estimate of the societal monetary value of a QALY (MVQALY) is mostly performed to inform a range of thresholds for accurately guiding cost-effectiveness decisions.

This study explores the degree of variation in the societal MVQALY based on a large sample of the population in Spain. It uses a discrete choice experiment and a time trade-off exercise to derive a value set for utilities, followed by a willingness to pay questionnaire. The study reveals that the societal values for a QALY, corresponding to different EQ-5D-3L health gains, vary approximately between €10,000 and €30,000. Ironically, the MVQALY associated with larger improvements on QoL was found to be lower than with moderate QoL gains, meaning that WTP is less than proportional to the size of the QoL improvement. The authors further explored whether budgetary restrictions could be a reason for this by analysing responses of individuals with higher income and found out that it may somewhat explain this, but not fully. As this, at face value, implies there should be a lower cost per QALY threshold for interventions with largest improvement of health than with moderate improvements, it raises a lot of questions and forces you to interpret the findings with caution. The authors suggest that the diminishing MVQALY is, at least partly, produced by the lack of sensitivity of WTP responses.

Though I think that the article does not provide a clear take-home message, it makes the readers re-think the very underlying norms of estimating monetary values of QALYs. The study eventually raises more questions than providing answers but could be useful to further explore areas of utility research.

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Are QALYs #ableist?

As many of us who have had to review submitted journal articles, thesis defenses, grant applications, white papers, and even published literature know, providing feedback on something that is poorly conceived is much harder than providing feedback on something well done.

This is going to be hard.

Who is ValueOurHealth?

The video above comes from the website of “ValueOurHealth.org”; I would tell you more about them, but there is no “About Us” menu item on the website. However, the website indicates that they are a group of patient organizations concerned about:

“The use of flawed, discriminatory value assessments [that] could threaten access to care for patients with chronic illnesses and people with disabilities.”

In particular, who find issue with value assessments that

“place a value on the life of a human based on their health status and assume every patient will respond the same way to treatments.”

QALYs, according to these concerned patient groups, assign a value to human beings. People with lower values (like Jessica, in the video above), then, will be denied coverage because their life is “valued less than someone in perfect health” which means “less value is also placed on treating” them. (Many will be quick to notice that health states and QALYs are used interchangeably here. I try to explain why below.)

It’s not like this is a well-intended rogue group who simply misunderstands the concept of a QALY, requires someone to send them a polite email, and then we can all move on. Other groups have also asserted that QALYs unfairly discriminate against the aged and disabled, and include AimedAlliance, Alliance for Patient Access, Institute for Patient Access, Alliance for Aging Research, and Global Liver Institute. There are likely many more patient groups that abhor QALYs (and definite articles/determiners, it seems) out there, and are justifiably concerned about patient access to therapy. But these are all the ones I could find through a quick search and sitting from my perch in Canada.

Why do they hate QALYs?

One can infer pretty quickly that ValueOurHealth and their illustrative message is largely motivated by another very active organization, the “Partnership to Improve Patient Care” (PIPC). The video, and the arguments about “assigning QALYs” to people, seem to stem from a white paper produced by the PIPC, which in turn cites a very nicely written paper by Franco Sassi (of Imperial College London), that explains QALY and DALY calculations for researchers and policymakers.

The PIPC white paper, in fact, uses the very same calculation provided by Prof. Sassi to illustrate the impact of preventing a case of tuberculosis. However, unlike Prof. Sassi’s illustrative example, the PIPC fails to quantify the QALYs gained by the intervention. Instead they simply focus on the QALYs an individual who has tuberculosis for 6 months will experience. (0.36, versus 0.50, for those keeping score). After some further discussion about problems with measuring health states, the PIPC white paper then skips ahead to ethical problems with QALYs central to their position, citing a Value in Health paper by Erik Nord and colleagues. One of the key problems with the QALY according to the PIPC and argued in the Nord paper goes as follows:

“Valuing health gains in terms of QALYs means that life-years gained in full health—through, for instance, prevention of fatal accidents in people in normal health—are counted as more valuable than life-years gained by those who are chronically ill or disabled—for instance, by averting fatal episodes in people with asthma, heart disease, or mental illness.”

It seems the PIPC assume the lower number of QALYs experienced by those who are sick equates with the value of lives to payers. Even more interestingly, Prof. Nord’s analysis says nothing about costs. While those who are older have fewer QALYs to potentially gain, they also incur fewer costs. This is why, contrary to the assertion of preventing accidents in healthy people, preventive measures may offer a similar value to treatments when both QALYS and costs are considered.

It is also why an ICER review showed that alemtuzumab is good value in individuals requiring second-line treatment for relapse-remitting multiple sclerosis (1.34 QALYs can be gained compared to the next best alternative and at a lower cost then comparators), while a policy of annual mammography screening of similarly aged (i.e., >40) healthy women is of poor economic value (0.036 QALYs can be gained compared to no screening at an additional cost of $5,500 for every woman). Mammography provides better value in older individuals. It is not unlike fracture prevention and a myriad of other interventions in healthy, asymptomatic people in this regard. Quite contrary to the assertion of these misinformed groups, many interventions represent increasingly better value in frail, disabled, and older patients. Relative risks create larger yields when baseline risks are high.

None of this is to say that QALYs (and incremental cost-effectiveness ratios) do not have problems. And the PIPC, at the very least, should be commended for trying to advance alternative metrics, something that very few critics have offered. Instead, the PIPC and like-minded organizations are likely trapped in a filter bubble. They know there are problems with QALYs, and they see expensive and rare disease treatments being valued harshly. So, ergo, blame the QALY. (Note to PIPC: it is because the drugs are expensive, relative to other life-saving things, not because of your concerns about the QALY.) They then see that others feel the same way, which means their concerns are likely justified. A critique of QALYs issued by the Pioneer Institute identifies many of these same arguments. One Twitterer, a disabled Massachusetts lawyer “alive because of Medicaid” has offered further instruction for the QALY-naive.

What to do about it?

As a friend recently told me, not everyone is concerned with the QALY. Some don’t like what they see as a rationing approach promoted by the Institute for Clinical and Economic Review (ICER) assessments. Some hate the QALY. Some hate both. Last year, Joshua T. Cohen, Dan Ollendorf, and Peter Neumann published their own blog entry on the effervescing criticism of ICER, even allowing the PIPC head to have a say about QALYs. They then tried to set the record straight with these thoughts:

While we applaud the call for novel measures and to work with patient and disability advocates to understand attributes important to them, there are three problems with PIPC’s position.

First, simply coming up with that list of key attributes does not address how society should allocate finite resources, or how to price a drug given individual or group preferences.

Second, the diminished weight QALYs assign to life with disability does not represent discrimination. Instead, diminished weight represents recognition that treatments mitigating disability confer value by restoring quality of life to levels typical among most of the population.

Finally, all value measures that inform allocation of finite resources trade off benefits important to some patients against benefits potentially important to others. PIPC itself notes that life years not weighted for disability (e.g., the equal value life-year gained, or evLYG, introduced by ICER for sensitivity analysis purposes) do not award value for improved quality of life. Indeed, any measure that does not “discriminate” against patients with disability cannot award treatments credit for improving their quality of life. Failing to award that credit would adversely affect this population by ruling out spending on such improvements.

Certainly a lot more can be said here.

But for now, I am more curious what others have to say…