Just Published: Systematic Review of Utility Weights Used in Economic Evaluations of Vaccines for Paediatric Infectious Diseases

This blog reports results of a systematic review of the sources and characteristics of utility weights used in economic evaluations of paediatric vaccines in developed countries.

A new study has recently been published in Value in Health, which reports a systematic review of the sources and characteristics of utility weights used to assess the cost-effectiveness of vaccines for infectious diseases in paediatric populations. The report is authored by OHE’s Mike Herdman, Amanda Cole, and Professor Nancy Devlin, alongside colleagues from Sanofi-Pasteur.

The review looked at studies that elicited or used utility weights in cost-effectiveness analyses of vaccines in paediatric age populations with any of 17 vaccine-preventable infectious diseases. The results are presented following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology.

15 articles were identified which described the elicitation of utility weights intended for use in the populations of interest and 86 articles which employed utility weights in economic modelling studies for vaccines in those populations.

A variety of populations were used to elicit utility weights including parents and carers, the children themselves, or samples of the general population. Expert panels were also used on occasion to estimate utilities.

As regards the methods used to generate utilities, these were also quite variable and included direct measurement of preferences using a variety of preference elicitation techniques such as time trade off (TTO), contingent valuation, and willingness to pay. In other cases, utilities were obtained via the application of preference-based measures such as EQ-5D or the Health Utilities Index (HUI), with values for adult health states being applied to paediatric populations in some cases.

In modelling studies which employed utility weights, the sources of the utilities used were often not clearly described or were poorly reported, and/or based on weak underlying evidence.

Assumptions were often made when constructing the models; for example, in an economic model for influenza vaccine, it was assumed that utility weights for children would be equivalent to those of ‘otherwise healthy adults’.

In some cases, we also noted considerable variation in the utility weights assigned to the same or very similar health states. For example, in models for vaccination in pneumococcal disease, a utility weight of 0.45 was used for deafness in one study compared to a utility decrement of 0.8 used for hearing loss in another study.

We conclude that the scarcity of appropriate utility weights for vaccine-preventable infectious diseases in children and a lack of standardization in their use will hinder accurate cost-effectiveness assessments of interventions to prevent them. We recommend that more effort should be made to standardise economic evaluations in this area.

Access the full paper here.

This is a companion paper to one which was also published recently in Value in Health and which reported on the use of Patient Reported Outcomes (PROs) in Paediatric Populations with Vaccine-Preventable Infectious Diseases. Both papers are the product of the Patient-Reported Outcomes in Children with Infectious Diseases (PROCHID) project.

In recent years, members of OHE have contributed to several studies involving the development and/or use of PRO measures in younger populations, including:

• Development [open access] and validation [open access] of the EQ-5D-Y, the version of EQ-5D for children
• A pilot study of the valuation of EQ-5D-Y, including exploration of the effect of the ‘perspective’ adopted in valuation (currently being prepared for publication)
• Development and validation of a condition-specific measure of HRQOL for use in short stature children [open access]
• Development and use of a widely used, generic measure of children’s HRQOL, the KIDSCREEN [open access]
• Exploration of socioeconomic inequalities in HRQOL in children and adolescents across Europe 

For more information on OHE’s research in this area, please contact Mike Herdman or Nancy Devlin.