Campbell Collaboration Colloquium 2013 Incorporating economic evidence into systematic reviews: an introduction and methods update Ian Shemilt

Economics

Economic evaluation

CEA and CBA Cost Description... Measurement... Valuation... ...of resource use Effect Description... Measurement... Valuation... ...of outcomes $$$ $$$ Cost per unit of outcome (ICER) Incremental net benefit

Economic evaluation of social programs and policies

Economic evaluation of social programs and policies

Economic evaluation of social programs and policies

Economic evaluation of social programs and policies

Economic evaluation of social programs and policies

Economics methods for C2 reviews

When to include economics? Expected incremental effect (Ex ante) incremental cost (Ex ante) Probability economic evidence could change potential adoption decisions? (Ex ante) Priority for incorporating economic perspectives and evidence? Small Low Low Probability Low priority High Probability Medium priority Large Very low priority High High priority Audio commentary: This decision algorithm was developed by The Johns Hopkins University Evidence-based Practice Center as part of work undertaken for the US Agency for Healthcare Research and Quality during 2010 that included an aim to develop a framework for deciding, ex ante, when evidence for resource use, costs and cost-effectiveness is most likely to provide policy-relevant information when included in systematic reviews of clinical outcomes. The algorithm provides three criteria to be used to prioritise reviews for inclusion of economic perspectives and evidence: first, the expected incremental effect of an intervention (compared with alternatives); second, the expected incremental cost of the intervention (compared with alternatives); and third, the likelihood that economic evidence could change potential decisions about use of an intervention. Each of these three criteria are dichotomized for simplicity: large or small incremental effect, high or low incremental cost, and a high or low probability that economic evidence will affect decisions. The size of incremental effects and costs are quantitative measures. Clearly it is difficult to estimate the likely size of incremental effects and costs, even in these broad, dichotomized terms, in advance of conducting the systematic review (so that, in practice, it may be easier to apply when planning updates of already published Cochrane reviews, based on empirical evidence for (for example) incremental effect presented in the published version). However, this is an essential first step in any efficacy, effectiveness or economic evaluation, just as in planning systematic reviews of such studies. Here, the focus should be on primary outcomes for expected incremental effect and on overall cost of interventions (encompassing both ‘up-front’ costs, or resource inputs and ‘downstream costs’, or resource consequences) for expected incremental cost. In considering expected incremental costs, it can be helpful to develop a clinical event pathway description to provide a conceptual diagram of the main pathways of clinical events that have distinct resource implications or health outcomes associated with them, from the point of introduction of the interventions being compared, through subsequent changes in the management of patients, to final health outcomes. Further information on the use of clinical event pathways to help authors conceptualize economic components of reviews is available in Chapter 15 of the Cochrane Handbook for Systematic Reviews of Interventions. Issues of perspectives and time horizons of potential adoption decisions, introduced earlier in this module, are important determinants of the scope of clinical event pathway descriptions and associated ex ante judgments regarding expected incremental costs and effects. Authors are encouraged to contact their Cochrane Review Group for assistance to identify health economists linked to The Cochrane Collaboration who can provide specialist advice to support these ex ante judgments. The ex ante probability that economic evidence could change potential adoption decisions is a largely subjective judgment. This judgment is again difficult to make, given the international audience of end users of Cochrane reviews and the consequent large number of decision-making constituencies that will vary in terms of their use of evidence in the decision making process, but it can be guided by thinking about several factors. For example, what are the different levels at which adoption decisions are likely to be taken? Do potential adoption decisions cluster more towards the local, clinical management, commissioning, single provider or more towards national level and policy makers. A useful rule of thumb may be that, the more the large set of potential decisions cluster towards the local, the greater the limits on resources and the more likely that decision makers will be cognizant of resource limitations and be interested in evidence for resource use, costs and cost-effectiveness. Also, how many alternative management strategies exist for target patient populations? Is there only one alternative or are there multiple effective options? In cases with a single effective intervention, costs are likely to play a less important role in the decision making process. Based on these two factors, a national decision for a new biologic that would be the only effective treatment for a particular type of cancer would be less likely to focus on costs, while a decision at a community health center about a new treatment for hyperlipidemia would likely be heavily influenced by costs. Part of the consideration is whether the intervention fits within the budget of the decision makers. Consideration of whether economic evidence could change potential adoption decisions can also be a function of the politics of the decision context. For example, in some cases, such as the only treatment for an otherwise fatal condition, evidence for costs and cost-effectiveness is less likely to make a difference in treatment decisions made by clinicians (although, such considerations may limit the freedom of action of clinicians). This decision algorithm excludes situations in which the intervention is expected to be associated with negative incremental cost and a positive incremental effect relative to the current standard practice (and vice versa); in other words situations in which decisions to adopt or reject are expected to be straightforward because the intervention dominates, or is dominated by, current standard practice; situations represented by the lower right hand and upper left hand squares in the 3 x 3 permutation matrix shown earlier. Perhaps more controversially, it also excludes situations in which the intervention is expected to be both less effective and less costly than current standard practice (one of the situations in which further judgment is required, represented by the lower left hand square in the 3 x 3 permutation matrix shown earlier. Rather the algorithm focuses on a set of situations in which the intervention is expected to be both more effective and more costly than current standard practice - this is another set of situations in which further judgment is required, because decision makers need to decide whether the health gain justifies the level of extra cost that would be incurred; the set of situations represented by the upper right hand square in the 3 x 3 permutation matrix shown earlier. There are two rows in the table for which the decision is relatively “obvious.” The first is the case of a large incremental beneficial effect, a low incremental cost, and a low probability of the economic evidence changing the decision. In that case, there is a very low priority placed on the incorporation of economic perspectives and evidence into the Cochrane intervention review. This is because with a large beneficial effect on health (which is likely to translate into lower subsequent use of health services and lower associated health care costs) and small input costs, the intervention is ex ante very likely to be cost-saving overall. This observation can be made in commentary within the discussion section, without the need to go much further by seeking to incorporate detailed analysis of economic evidence into the review. Conversely, if the expected incremental beneficial effect is small, the expected incremental costs are high, and the economic evidence has a high probability of changing the decision, then there is a high priority placed on the incorporation of economic perspectives and evidence. The other rows represent six further situations that fall between these two extremes. For example, the fifth row represents a situation in which the incremental beneficial effect is small, the incremental cost is high, and the probability of changing the decision is low, in which case it might be more important but not an absolute priority to incorporate economic perspectives and evidence. The second row represents a situation in which the incremental beneficial effect is small, the incremental cost is low, and the economic evidence has a high probability of changing the decision. This scenario may occur when, although the expected cost impact is small, the health condition targeted by the intervention has high prevalence, such that the cumulative impact of small changes in costs across a large number of treated patients adds up to a large overall change in costs. It is important to understand that if the ex ante judgment is that it is a low (or very low) priority to incorporate economic perspectives and evidence, this does not imply that including economic perspectives in the review would provide little (or very little) relevant or useful information for decision makers. Rather it implies that it is a low (or very low) priority to incorporate economic evidence into all sections of the review, or to subject economic evidence to the full Cochrane review process, from the stages of question formulation and searching for studies, through to the analysis, presentation and interpretation of results. We will elaborate this distinction between economic perspectives and economic evidence in a few moments, when we introduce the currently proposed framework for incorporating such perspectives and evidence into Cochrane intervention reviews. Overall and in general, it is likely to prove most useful to consider incorporating economic evidence into reviews when the total change in resource use or costs expected to occur as a result of the intervention is large.

c-cemg.org

Tension C2 reviews have a global audience Resource use and costs vary between settings and over time Focus on key economic trade-offs Place in context of evidence for effectiveness

Chapter 3 – Explanatory framework

No economic evaluations?

Resource use data coding tool Covers six categories of resource inputs: Personnel time – program delivery Personnel time – program specific training Personnel time – supervision, monitoring, and feedback Equipment, supplies, and materials Buildings and facilities Overheads

CCEMG-EPPI Cost Converter

Campbell Collaboration Colloquium 2013 Incorporating economic evidence into systematic reviews: an introduction and methods update Ian Shemilt