Rachel Houten’s journal round-up for 11th November 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.

A comparison of national guidelines for network meta-analysis. Value in Health [PubMed] Published October 2019

The evolving treatment landscape results in a greater dependence on indirect treatment comparisons to generate estimates of clinical effectiveness, where the current practice has not been compared to the proposed new intervention in a head-to-head trial. This paper is a review of the guidelines of reimbursement bodies for conducting network meta-analyses. Reassuringly, the authors find that it is possible to meet the needs of multiple agencies with one analysis.

The authors assign three categories to the criteria; “assessment and analysis to test assumptions required for a network meta-analysis, presentation and reporting of results, and justification of modelling choices”, with heterogeneity of the included studies highlighted as one of the key elements to be sure to include if prioritisation of the criteria is necessary. I think this is a simple way of thinking about what needs to be presented but the ‘justification’ category, in my experience, is often given less weight than the other two.

This paper is a useful resource for companies submitting to multiple HTA agencies with the requirements of each national body displayed in tables that are easy to navigate. It meets a practical need but doesn’t really go far enough for me. They do signpost to the PRISMA criteria, but I think it would have been really good to think about the purpose of the submission guidelines; to encourage a logical and coherent summary of the approaches taken so the evidence can be evaluated by decision-makers.

Variation in responsiveness to warranted behaviour change among NHS clinicians: novel implementation of change detection methods in longitudinal prescribing data. BMJ [PubMed] Published 2nd October 2019

I really like this paper. Such a lot of work, from all sectors, is devoted to the production of relevant and timely evidence to inform practice, but if the guidance does not become embedded into the real world then its usefulness is limited.

The authors have managed to utilize a HUGE amount of data to identify the real reaction to two pieces of guidance recommending a change in practice in England. The authors used “trend indicator saturation”, which I’m not ashamed to admit I knew nothing about beforehand, but it is explained nicely. Their thoughtful use of the information available to them results in three indicators of response (in this case the deprescribing of two drugs) around when the change occurs, how quickly it occurs, and how much change occurs.

The authors discover variation in response to the recommendations but suggest an application of their methods could be used to generate feedback to clinicians and therefore drive further response. As some primary care practices took a while to embed the guidance change into their prescribing, the paper raises interesting questions as to where the barriers to the adoption of guidance have occurred.

What is next for patient preferences in health technology assessment? A systematic review of the challenges. Value in Health Published November 2019

It may be that patient preferences have a role to play in the uptake of guideline recommendations, as proposed by the authors of my final paper this week. This systematic review, of the literature around embedding patient preferences into HTA decision-making, groups the discussion in the academic literature into five broad areas; conceptual, normative, procedural, methodological, and practical. The authors state that their purpose was not to formulate their own views, merely to present the available literature, but they do a good job of indicating where to find more opinionated literature on this topic.

Methodological issues were the biggest group, with aspects such as the sample selection, internal and external validity of the preferences generated, and the generalisability of the preferences collected from a sample to the entire population. However, in general, the number of topics covered in the literature is vast and varied.

It’s a great summary of the challenges that are faced, and a ranking based on frequency of topic being mentioned in the literature drives the authors proposed next steps. They recommend further research into the incorporation of preferences within or beyond the QALY and the use of multiple-criteria decision analysis as a method of integrating patient preferences into decision-making. I support the need for “a scientifically and valid manner” to integrate patient preferences into HTA decision-making but wonder if we can first learn of what works well and hasn’t worked so well from the attempts of HTA agencies thus far.

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Rachel Houten’s journal round-up for 8th July 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.

Adjusting for inflation and currency changes within health economic studies. Value in Health Published 13th June 2019

The purpose of the paper is to highlight the need for transparency in the reporting of methods of currency conversions and adjustments to costs to take inflation into account, in economic evaluations. It chimes with other recent literature which is less prescriptive in terms of providing methods guidelines and more about advocating the “tell us what you did and why” approach. It reminds me of my very first science lesson in high school where we were eager to get our hands on the experiments yet the teacher (met by much eye-rolling) insisted on the importance of describing the methods of any ‘study’. With space at a premium in academic writing, I know, and I’m likely guilty of, some transparency in assumptions being culled, but papers such as this highlight their necessity.

The authors discuss which inflation measure to base the adjustments on, whether to convert local currencies to US or International dollars, three methods of adjusting for inflation, and what to do when costs from other settings are part of the analysis. With a focus on low- and middle-income countries, and using a hypothetical example, the authors demonstrate that employing three different methods of adjusting for inflation can result in a large range in the final estimates.

The authors acknowledge that it is not a one-size-fits-all approach but favour a ‘mixed approach’ where micro-costing is possible and items can be classified as tradable and non-tradable, as they say this is likely to produce the most accurate estimates. However, a study reliant on previously published costing information would need to follow an alternative approach, of which there are two others detailed in the paper.

In terms of working with data from low- and middle-income countries, I can’t say it is my forté. However, the paper summarises the pros and cons of each of their proposed approaches in a straightforward way. The authors include a table that I think would provide an excellent reference point for anyone considering the best approach for their specific set of circumstances.

An updated systematic review of studies mapping (or cross‑walking) measures of health‑related quality of life to generic preference‑based measures to generate utility value. Applied Health Economics and Health Policy [PubMed] [RePEc] Published 3rd April 2019

This is an update of a review of studies published before 2007, which found 30 studies mapping to generic preference-based measures. This latest paper cites 180 included studies with a total of 233 mapping functions reported. The majority of the mapping functions were to the EQ-5D (147 mapping functions) with the second largest group mapping to the SF-6D (45 mapping functions).

Along with an increase in volume of mapping studies since the last review, there has been a marked increase in the different types of regression methods used, which signals a greater consideration of the distribution of the underlying utility data. Reporting on how well the mapping algorithms predict utility in different sub-groups has also increased.

The authors highlight that although mapping can fill an evidence gap, the uncertainty in the estimates is greater than directly measuring health-related quality of life in prospective studies. The authors signpost to ISPOR guidelines for the reporting of mapping studies and emphasise the need to include measurements of error as well as a plot of predicted versus observed values, to enable the user to understand and incorporate the accuracy of the mapping in their economic evaluations.

As stated by the authors, the results of this review provides a useful resource in terms of a catalogue of mapping studies, however it lacks any quality assessment of the studies (also made clear by the authors), so the choice of which mapping algorithm to use is still ours, and takes some thought.  The supplementary Excel file is a great resource to aid the choice as it includes some information about the populations used in the mapping studies alongside the methods, but more studies comparing mapping functions with the same aim against each other would be welcomed.

Investigating the relationship between formal and informal care: an application using panel data for people living together. Health Economics [PubMed] Published 7th June 2019

This paper adds to the literature on informal care by considering co-resident informal care in a UK setting using data from the British Household Panel Survey (BHPS). There has been an increase in the proportion of people receiving non-state provided care in recent years in the UK, and the BHPS also enables the impact of informal care on the use of each of these types of formal care to be explored.

The authors used an instrument for informal care to try to prevent bias due to correlations with other variables such as health. The instrument used for the availability of informal care was the number of adult daughters as it was found to be the most predictive (oh dear, I’ve two sons!). The authors then estimated the impact of informal care on home help, health visitor use, GP visits, and hospital stays.

In this study, informal care was a substitute for both state and non-state home help (with the impact greater for state home help) and complimentary to health visitor use, GP visits, and hospital stays. The authors suggest this may be due to the tasks completed by these different types of service providers and how household tasks are more likely to be undertaken by informal care givers than those more medical in nature. The fact this study considers co-residential care from any household member may explain the stronger substitution effect in this study compared to previous studies looking at informal caregivers living elsewhere as it could be assumed the caregiver residing with the care recipient is more able to provide care.

I find the make-up of households and how that impacts on the need for healthcare resources really interesting, especially as it is generally considered that informal care and the work of charities bolsters the NHS. The results of this study suggest that increases in informal care could generate savings in terms of the need for home help, but an increase in formal care resource use. The reasons for the complimentary relationship between informal care and health visitor, GP, and hospital visits need further exploration.

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Rachel Houten’s journal round-up for 22nd April 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.

To HTA or not to HTA: identifying the factors influencing the rapid review outcome in Ireland. Value in Health [PubMed] Published 6th March 2019

National health services are constantly under pressure to provide access to new medicines as soon as marketing authorisation is granted. The NCPE in the Republic of Ireland has a rapid review process for selecting medicines that require a full health technology assessment (HTA), and the rest, approximately 45%, are able to be reimbursed without such an in-depth analysis.

Formal criteria do not exist. However, it has previously been suggested that the robustness of clinical evidence of at least equivalence; a drug that costs the same or less; an annual (or estimated) budget impact of less than €0.75 million to €1 million; and the ability of the current health systems to restrict usage are some of what is considered when making the decision.

The authors of this paper used the allocation over the past eight years to explore the factors that drive the decision to embark on a full HTA. They found, unsurprisingly, that first-in-class medicines are more likely to require an HTA as too are those with orphan status. Interestingly, the clinical area influenced the requirement for a full HTA, but the authors consider all of these factors to indicate that high-cost drugs are more likely to require a full assessment. Drug cost information is not publicly available and so the authors used the data available on the Scottish Medicine Consortium website as a surrogate for costs in Ireland. In doing so, they were able to establish a relationship between the cost per person for each drug and the likelihood of the drug having a full HTA, further supporting the idea that more expensive drugs are more likely to require HTA. On the face of it, this seems eminently sensible. However, my concern is that, in a system that is designed to deliberately measure cost per unit of health care (usually QALYs), there is the potential for lower-cost but ineffective drugs to become commonplace while more expensive medicines are subject to more rigor.

The paper provides some insight into what drives a decision to undertake a full HTA in Ireland. The NICE fast-track appraisal system operates as an opt-in system where manufacturers can ask to follow this shorter appraisal route if their drug is likely to produce an ICER of £10,000 or less. As my day job is for an Evidence Review Group (opinions my own), how things are done elsewhere – unsurprisingly – captured my attention. The desire to speed up the HTA process is obvious but the most appropriate mechanisms in which to do so are far from it. Whether or not the same decision is ultimately made is what concerns me.

NHS joint working with industry is out of public sight. BMJ [PubMed] Published 27th March 2019

This paper suggests that ‘joint working arrangements’ – a government-supported initiative between pharmaceutical companies and the NHS – are not being implemented according to guidelines on transparency. These arrangements are designed to promote collaborative research between the NHS and industry and help advance NHS provision of services.

The authors used freedom of information requests to obtain details on how many trusts were involved in joint working arrangements in 2016 and 2017. The declarations of payments made by drug companies are disclosed but the corresponding information from trusts is less readily accessible, and in some cases access to any details was prevented. Theoretically, the joint working arrangements are supposed to be void of any commercial influence on what is prescribed, but my thoughts are echoed in this paper when it asks “what’s in it for the private sector?” The sheer fact that some NHS trusts were unwilling to provide the BMJ with the information requested due to ‘commercial interest’ rings huge alarm bells.

I’m not completely cynical of these arrangements in principle, though, and the paper cites a couple of projects that involved building new facilities for age-related macular generation, which likely offer benefits to patients, and possibly much faster than could have been achieved with NHS funding alone. Some of the arrangements intend to push the implementation of national guidance, which, as a small cog in the guidance generation machine, I unashamedly (and predictably) think is a good thing.

Does it matter to us? As economists, it means that any work based on national practice and costs is likely to be unrepresentative of what actually happens. This, however, has always been the case to some extent, with variations in local service provision and the negotiation power of trusts with large volumes of patients. A national register of the arrangements would have the potential to feed into economic analysis, even if just as a statement of awareness.

Can the NHS survive without getting into bed with industry? Probably not. I think the paper does a good job of presenting the arguments on all sides and pushing for increasing availability of what is happening.

Estimating joint health condition utility values. Value in Health [PubMed] Published 22nd February 2019

I’m really interested in how this area is developing. Multi-morbidity is the norm, especially as we age. Single condition models are criticised for their lack of representation of patients in the real world. Appropriately estimating the quality of life of people with several chronic conditions, when only individual condition data are available, is incredibly difficult.

In this paper, parametric and non-parametric methods were tested on a dataset from a large primary care patient survey in the UK. The multiplicative approach was the best performing for two conditions. When more than two conditions were considered, the linear index (which incorporates additive, multiplicative, and minimum models with the use of linear regression and parameter weights derived from the underlying data) achieved the best results.

Including long-term mental health within the co-morbidities for which utility was estimated produced biased estimates. The authors discuss some possible explanations for this, including the fact that the anxiety and depression question in the EQ-5D is the only one which directly maps to an individual condition, and that mental health may have a causal effect on physical health. This is a fascinating finding, which has left me somewhat scratching my head as to how this oddity could be addressed and if separate methods of estimation will need to be used for any population with multi-morbidity including mental health conditions.

It did make me wonder if more precise EQ-5D data could be helpful to uncover the true interrelationships between joint health conditions and quality of life. The EQ-5D asks patients to think about their health state ‘today’. Although the primary care dataset used includes 16 chronic health conditions, it doesn’t, as far as I know, contain any information on the symptoms apparent on the day of quality of life assessment, which could be flaring or absent at any given time. This is a common problem with the EQ-5D and I don’t think a readily available data source of this type exists, so it’s a thought on ideals. Unsurprisingly, the more joint health conditions to be considered, the larger the error in terms of estimation from individual conditions. This may be due to the increasing likelihood of overlap in the symptoms experienced across conditions and thus a violation of the assumption that quality of life for an individual condition is independent of any other condition.

Whether the methodology remains robust for populations outside of the UK or for other measures of utility would need to be tested, and the authors are keen to highlight the need for caution before running away and using the methods verbatim. The paper does present a nice summary of the evidence to date in this area, what the authors did, and what it adds to the topic, so worth a read.

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