Chris Sampson’s journal round-up for 23rd 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.

The Internet and children’s psychological wellbeing. Journal of Health Economics Published 13th December 2019

Here at the blog, we like the Internet. We couldn’t exist without it. We vie for your attention along with all of the other content factories (or “friends”). But there’s a well-established sense that people – especially children – should moderate their consumption of Internet content. The Internet is pervasive and is now a fundamental part of our day-to-day lives, not simply an information source to which we turn when we need it. Almost all 12-15 year olds in the UK use the Internet. The ubiquity of the Internet makes it difficult to test its effects. But this paper has a good go at it.

This study is based on the idea that broadband speeds are a good proxy for Internet use. In England, a variety of public and private sector initiatives have resulted in a distorted market with quasi-random assigment of broadband speeds. The authors provide a very thorough explanation of children’s wellbeing in relation to the Internet, outlining a range of potential mechanisms.

The analysis combines data from the UK’s pre-eminent household panel survey (Understanding Society) with broadband speed data published by the UK regulator Ofcom. Six wellbeing outcomes are analysed from children’s self-reported responses. The questions ask children how they feel about their lives – measured on a seven-point scale – in relation to school work, appearance, family, friends, school attended, and life as a whole. An unbalanced panel of 6,310 children from 2012-2017 provides 13,938 observations from 3,765 different Lower Layer Super Output Areas (LSOA), with average broadband speeds for each LSOA for each year. Each of the six wellbeing outcomes is modelled with child-, neighbourhood- and time-specific fixed effects. The models’ covariates include a variety of indicators relating to the child, their parents, their household, and their local area.

A variety of models are tested, and the overall finding is that higher broadband speeds are negatively associated with all of the six wellbeing indicators. Wellbeing in relation to appearance shows the strongest effect; a 1% increase in broadband speed reduces happiness with appearance by around 0.6%. The authors explore a variety of potential mechanisms by running pairs of models between broadband speeds and the mechanism and between the mechanism and the outcomes. A key finding is that the data seem to support the ‘crowding out’ hypothesis. Higher broadband speeds are associated with children spending less time on activities such as sports, clubs, and real world social interactions, and these activities are in turn positively associated with wellbeing. The authors also consider different subgroups, finding that the effects are more detrimental for girls.

Where the paper falls down is that it doesn’t do anything to convince us that broadband speeds represent a good proxy for Internet use. It’s also not clear exactly what the proxy is meant to be for – use (e.g. time spent on the Internet) or access (i.e. having the option to use the Internet) – though the authors seem to be interested in the former. If that’s the case, the logic of the proxy is not obvious. If I want to do X on the Internet then higher speeds will enable me to do it in less time, in which case the proxy would capture the inverse of the desired indicator. The other problem I think we have is in the use of self-reported measures in this context. A key supposed mechanism for the effect is through ‘social comparison theory’, which we might reasonably expect to influence the way children respond to questions as well as – or instead of – their underlying wellbeing.

One-way sensitivity analysis for probabilistic cost-effectiveness analysis: conditional expected incremental net benefit. PharmacoEconomics [PubMed] Published 16th December 2019

Here we have one of those very citable papers that clearly specifies a part of cost-effectiveness analysis methodology. A better title for this paper could be Make one-way sensitivity analysis great again. The authors start out by – quite rightly – bashing the tornado diagram, mostly on the basis that it does not intuitively characterise the information that a decision-maker needs. Instead, the authors propose an approach to probabilistic one-way sensitivity analysis (POSA) that is a kind of simplified version of EVPPI (expected value of partially perfect information) analysis. Crucially, this approach does not assume that the various parameters of the analysis are independent.

The key quantity created by this analysis is the conditional expected incremental net monetary benefit (cINMB), conditional, that is, on the value of the parameter of interest. There are three steps to creating a plot of the POSA results: 1) rank the costs and outcomes for the sampled values of the parameter – say from the first to the last centile; 2) plug in a cost-effectiveness threshold value to calculate the cINMB at each sampled value; and 3) record the probability of observing each value of the parameter. You could use this information to present a tornado-style diagram, plotting the credible range of the cINMB. But it’s more useful to plot a line graph showing the cINMB at the different values of the parameter of interest, taking into account the probability that the values will actually be observed.

The authors illustrate their method using three different parameters from a previously published cost-effectiveness analysis, in each case simulating 15,000 Monte Carlo ‘inner loops’ for each of the 99 centiles. It took me a little while to get my head around the results that are presented, so there’s still some work to do around explaining the visuals to decision-makers. Nevertheless, this approach has the potential to become standard practice.

A head-on ordinal comparison of the composite time trade-off and the better-than-dead method. Value in Health Published 19th December 2019

For years now, methodologists have been trying to find a reliable way to value health states ‘worse than dead’. The EQ-VT protocol, used to value the EQ-5D-5L, includes the composite time trade-off (cTTO). The cTTO task gives people the opportunity to trade away life years in good health to avoid having to subsequently live in a state that they have identified as being ‘worse than dead’ (i.e. they would prefer to die immediately than to live in it). An alternative approach to this is the better-than-dead method, whereby people simply compare given durations in a health state to being dead. But are these two approaches measuring the same thing? This study sought to find out.

The authors recruited a convenience sample of 200 students and asked them to value seven different EQ-5D-5L health states that were close to zero in the Dutch tariff. Each respondent completed both a cTTO task and a better-than-dead task (the order varied) for each of the seven states. The analysis then looked at the extent to which there was agreement between the two methods in terms of whether states were identified as being better or worse than dead. Agreement was measured using counts and using polychoric correlations. Unsurprisingly, agreement was higher for those states that lay further from zero in the Dutch tariff. Around zero, there was quite a bit of disagreement – only 65% agreed for state 44343. Both approaches performed similarly with respect to consistency and test-retest reliability. Overall, the authors interpret these findings as meaning that the two methods are measuring the same underlying preferences.

I don’t find that very convincing. States were more often identified as worse than dead in the better-than-dead task, with 55% valued as such, compared with 37% in the cTTO. That seems like a big difference. The authors provide a variety of possible explanations for the differences, mostly relating to the way the tasks are framed. Or it might be that the complexity of the worse-than-dead task in the cTTO is so confusing and counterintuitive that respondents (intentionally or otherwise) avoid having to do it. For me, the findings reinforce the futility of trying to value health states in relation to being dead. If a slight change in methodology prevents a group of biomedical students from giving consistent assessments of whether or not a state is worse than being dead, what hope do we have?

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Thesis Thursday: Caroline Chuard

On the third Thursday of every month, we speak to a recent graduate about their thesis and their studies. This month’s guest is Dr Caroline Chuard who has a PhD from the University of Zurich. If you would like to suggest a candidate for an upcoming Thesis Thursday, get in touch.

Title
Three essays on the health effects of family policies
Supervisors
Hannes Schwandt, Josef Zweimüller
Repository link
https://www.zora.uzh.ch/id/eprint/172853/

Is there a strong health economics evidence base on family policies?

The literature on parental leave and family health is relatively young. This literature emphasises that the returns depend on several key features. First, the timing of measurement matters. Therefore, the effects differ according to whether they are measured in the short- versus long-run. Second, the initial level of parental leave and the extent to which parental leave is increased are both key influencing factors. As such, an introduction is more beneficial than an increase at an already generous level of parental leave. Third, the results depend on the targeted group.

But keep in mind that the effects of family policies on health outcomes are just one part of a large literature that studies the effect on other outcomes such as maternal labour market outcomes, fertility, and child cognitive and non-cognitive development (e.g. Ruhm (2000), Lalive and Zweimüller (2009), Baker and Milligan (2008), Dustmann and Schönberg (2012), Lalive et al. (2014), Carneiro et al. (2015), Dahl et al. (2016), Danzer and Lavy (2018), Butikofer et al. (2018) and many more which have recently been reviewed by Olivetti and Petrongolo (2017) and Rossin-Slater (2018)).

What policy changes were you able to evaluate in your research?

I exploit two types of family policy changes in two countries. On the one hand, I use three changes in parental leave duration in Austria and, on the other hand, I use cantonal variation in family allowances across Switzerland.

More specifically, Austria increased parental leave by 1 year to 2 years in July 1990. This was partially reversed again in July 1996, by exclusively reserving 6 months to fathers so that maternal leave was essentially reduced to 1.5 years. Finally, in July 2000, there was another large extension in paid parental leave by 1 year to 2.5 years. Enforcement of all these changes was very strict, changing from one day to another depending on giving birth in June or July. This sharp discontinuity allows me to employ a regression discontinuity design.

In the case of Switzerland, I analyse the impact of birth allowances (so-called baby bonuses) on fertility, newborn health and birth scheduling. I exploit a unique quasi-experimental setting of Switzerland’s family allowances system. In this system, cantons are free to choose whether they want to implement birth allowances and how much they want to pay. During the last 50 years, 11 cantons have introduced a baby bonus, all increase the amount paid thereafter, and two cantons even abolished the baby bonus after all. This gives rise to a lot of cantonal variation. Thus, I use a difference-in-differences setting where I can analyse both the introduction and the intensity of the treatment.

What were the key strengths of the data sets that you used?

For all my studies I rely on administrative data. Thus, I can use the universe of observations delivered with high quality, as both Austria and Switzerland have very reliable administrative data.

In the Austrian case, I can even combine several different data sets. Namely, I use the Austrian Social Security Database (ASSD), which covers the complete working history of every worker in Austria. The ASSD covers every birth of employed mothers and their actual duration of parental leave. I can link the ASSD to the Austrian Birth Register (ABR) recording newborn health outcomes and additional individual-level characteristics of the mother. Finally, for a part of Austria, I additionally merge the data to health outcomes recorded in the health insurance data. This data set records every outpatient doctor visit, prescribed medication, and hospital stays including diagnosis code.

All of this, together, gives a huge variety of different variables on an individual basis allowing me to study a broad set of outcomes (such as health outcomes next to the directly targeted labour market outcomes). Furthermore, the detailed level of information allows me to study the impact of labour market behaviour on two margins—the extensive margin of mothers who choose to work or not and the intensive margin of how much mothers choose to work. The richness of the data also makes it possible to analyse heterogeneous effects across mothers and by work environment.

Did the policies achieve what they were designed to achieve?

This is a little hard to tell from looking at my results only. For example, in Austria the initial increase of parental leave duration by 1 year was introduced so that fathers could take up to 6 months of the full duration. This policy reform was a result of parliamentary procedural requests which wanted to introduce paternal leave. Due to the flat benefit structure almost no fathers were taking up parental leave, which essentially resulted in an increase of maternal leave from 1 to 2 years and, ultimately, led to the second policy change by exclusively reserving 6 months out of the total 2 years for fathers.

However, what I want to mention here, note that I explicitly evaluated side effects. All three chapters of my dissertation highlight the importance of studying alternative and indirect outcome measures in addition to the direct measures targeted by policymakers.

For example, in the Swiss study, we only find little fertility effects, the directly targeted outcome measure of birth allowances, but a sizable and significant reduction in the stillbirth rate as well as a positive impact on birth weight. A policymaker, who would now only study fertility, would argue that birth allowances were expensive to implement with little to no result, which, however, does not capture the full story.

Is there heterogeneity in how family policy reforms affect families?

The answer depends on the person affected and the studied outcome. For example, the Austrian parental leave duration reform affects maternal work behaviour during pregnancy regardless of the mother’s socioeconomic background and the industry. This change in prenatal maternal work status doesn’t affect newborn health at all.

However, when I study the same reforms with respect to maternal health, there is substantial heterogeneity. The initial increase in leave length is especially good for low-wage and unmarried mothers. Reducing leave duration harms mothers with unhealthy babies, proxied by a preterm birth or low birth weight baby. Substantially increasing leave duration is, though, especially bad for maternal health of those mothers who already suffered from mental diseases pre-birth. Also, for the paper on the Swiss baby bonus, we find a more beneficial impact in the decline of stillbirths for low socioeconomic status mothers.

Based on your research, how would you design parental leave policies?

With my research, I tried to give a more complete picture on the impact of family policies by taking into account health outcomes which have vastly been neglected so far. Nevertheless, for a policy recommendation it is crucial to take the findings from the previous literature into account.

Firstly, introducing parental leave has generally been shown to be very beneficial for the cognitive development of children (Carneiro et al., 2015). Secondly, these returns are, however, quickly declining (Butikofer et al., 2018). In combination with my findings of no impact of working during pregnancy on child health and a negative impact of too long parental leave policies for maternal health (Chuard, 2018), I would clearly put the focus on mandatory leave in the first months of a newborn’s life. While this might seem obvious for many European countries, this is still not the case in the US. And even Europe might face the risk on the other end of the parental leave duration scale. Many European countries tend to expand leave rather generously both pre- and post-natal, which seems from my research not necessary (always keep in mind, these policies are extremely expensive) and could potentially even be harmful in the long-run.

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

MCDA-based deliberation to value health states: lessons learned from a pilot study. Health and Quality of Life Outcomes [PubMed] Published 1st July 2019

The rejection of the EQ-5D-5L value set for England indicates something of a crisis in health state valuation. Evidently, there is a lack of trust in the quantitative data and methods used. This is despite decades of methodological development. Perhaps we need a completely different approach. Could we instead develop a value set using qualitative methods?

A value set based on qualitative research aligns with an idea forwarded by Daniel Hausman, who has argued for the use of deliberative approaches. This could circumvent the problems associated with asking people to give instant (and possibly ill-thought-out) responses to preference elicitation surveys. The authors of this study report on the first ever (pilot) attempt to develop a consensus value set using methods of multi-criteria decision analysis (MCDA) and deliberation. The study attempts to identify a German value set for the SF-6D.

The study included 34 students in a one-day conference setting. A two-step process was followed for the MCDA using MACBETH (the Measuring Attractiveness by a Categorical Based Evaluation Technique), which uses pairwise comparisons to derive numerical scales without quantitative assessments. First, a scoring procedure was conducted for each of the six dimensions. Second, a weighting was identified for each dimension. After an introductory session, participants were allocated into groups of five or six and each group was tasked with scoring one SF-6D dimension. Within each group, consensus was achieved. After these group sessions, all participants were brought together to present and validate the results. In this deliberation process, consensus was achieved for all domains except pain. Then the weighting session took place, but resulted in no consensus. Subsequent to the one-day conference, a series of semi-structured interviews were conducted with moderators. All the sessions and interviews were recorded, transcribed, and analysed qualitatively.

In short, the study failed. A consensus value set could not be identified. Part of the problem was probably in the SF-6D descriptive system, particularly in relation to pain, which was interpreted differently by different people. But the main issue was that people had different opinions and didn’t seem willing to move towards consensus with a societal perspective in mind. Participants broadly fell into three groups – one in favour of prioritising pain and mental health, one opposed to trading-off SF-6D dimensions and favouring equal weights, and another group that was not willing to accept any trade-offs.

Despite its apparent failure, this seems like an extremely useful and important study. The authors provide a huge amount of detail regarding what they did, what went well, and what might be done differently next time. I’m not sure it will ever be possible to get a group of people to reach a consensus on a value set. The whole point of preference-based measures is surely that different people have different priorities, and they should be expected to disagree. But I think we should expect that the future of health state valuation lies in mixed methods. There might be more success in a qualitative and deliberative approach to scoring combined with a quantitative approach to weighting, or perhaps a qualitative approach informed by quantitative data that demands trade-offs. Whatever the future holds, this study will be a valuable guide.

Preference-based health-related quality of life outcomes associated with preterm birth: a systematic review and meta-analysis. PharmacoEconomics [PubMed] Published 9th December 2019

Premature and low birth weight babies can experience a whole host of negative health outcomes. Most studies in this context look at short-term biomedical assessments or behavioural and neurodevelopmental indicators. But some studies have sought to identify the long-term consequences on health-related quality of life by identifying health state utility values. This study provides us with a review and meta-analysis of such values.

The authors screened 2,139 articles from their search and included 20 in the review. Lots of data were extracted from the articles, which is helpfully tabulated in the paper. The majority of the studies included adolescents and focussed on children born very preterm or at very low birth weight.

For the meta-analysis, the authors employed a linear mixed-effects meta-regression, which is an increasingly routine approach in this context. The models were used to estimate the decrement in utility values associated with preterm birth or low birth weight, compared with matched controls. Conveniently, all but one of the studies used a measure other than the HUI2 or HUI3, so the analysis was restricted to these two measures. Preterm birth was associated with an average decrement of 0.066 and extremely low birth weight with a decrement of 0.068. The mean estimated utility scores for the study groups was 0.838, compared with 0.919 for the control groups.

Reviews of utility values are valuable as they provide modellers with a catalogue of potential parameters that can be selected in a meaningful and transparent way. Even though this is a thorough and well-reported study, it’s a bit harder to see how its findings will be used. Most reviews of utility values relate to a particular disease, which might be prevented or ameliorated by treatment, and the value of this treatment depends on the utility values selected. But how will these utility values be used? The avoidance of preterm or low-weight birth is not the subject of most evaluations in the neonatal setting. Even if it was, how valuable are estimates from a single point in adolescence? The authors suggest that future research should seek to identify a trajectory of utility values over the life course. But, even if we could achieve this, it’s not clear to me how this should complement utility values identified in relation to the specific health problems experienced by these people.

The new and non-transparent Cancer Drugs Fund. PharmacoEconomics [PubMed] Published 12th December 2019

Not many (any?) health economists liked the Cancer Drugs Fund (CDF). It was set-up to give special treatment to cancer drugs, which weren’t assessed on the same basis as other drugs being assessed by NICE. In 2016, the CDF was brought within NICE’s remit, with medicines available through the CDF requiring a managed access agreement. This includes agreements on data collection and on payments by the NHS during the period. In this article, the authors contend that the new CDF process is not sufficiently transparent.

Three main issued are raised: i) lack of transparency relating to the value of CDF drugs, ii) lack of transparency relating to the cost of CDF drugs, and iii) the amount of time that medicines remain on the CDF. The authors tabulate the reporting of ICERs according to the decisions made, showing that the majority of treatment comparisons do not report ICERs. Similarly, the time in the CDF is tabulated, with many indications being in the CDF for an unknown amount of time. In short, we don’t know much about medicines going through the CDF, except that they’re probably costing a lot.

I’m a fan of transparency, in almost all contexts. I think it is inherently valuable to share information widely. It seems that the authors of this paper do too. A lack of transparency in NICE decision-making is a broader problem that arises from the need to protect commercially sensitive pricing agreements. But what this paper doesn’t manage to do is to articulate why anybody who doesn’t support transparency in principle should care about the CDF in particular. Part of the authors’ argument is that the lack of transparency prevents independent scrutiny. But surely NICE is the independent scrutiny? The authors argue that it is a problem that commissioners and the public cannot assess the value of the medicines, but it isn’t clear why that should be a problem if they are not the arbiters of value. The CDF has quite rightly faced criticism over the years, but I’m not convinced that its lack of transparency is its main problem.

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