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The role of qualitative research in informing health economic evaluations

The role of qualitative research in informing health economic evaluations

01 February 2021

Damilola Olajide, Senior Adviser in Health Economics, RDS East Midlands

As RDS advisers, we often advise researchers how to incorporate different methodologies in order to best address their research questions and to satisfy the requirements of funders. At times, this can involve using different approaches and combinations that may be new to research teams. A recent example of this is the role qualitative research can play in informing health economic evaluations.

It is not always possible to undertake a full-fledged health economic evaluation alongside clinical trials. Trials have limited number of comparisons, and often have short follow-up time. These constrain their ability to collect all the evidence relevant to undertake a detailed economic evaluation. Trials only collect intervention-specific intermediate effects, rather than effects on health-related quality of life or survival that offers comparison across interventions.

Also, not all health care interventions can be subjected to trials. Yet, many high-quality NIHR funding applications face potential rejection for inability to demonstrate value for money through a detailed health economic component. It becomes more difficult for applications that are largely qualitative or mixed-method in design.

Model based health economic evaluations

Model-based health economic evaluations help to understand the effectiveness of new and existing interventions based on evidence accumulated from knowledge and real-life experience. These models integrate multiple factors into a single decision analytical framework to inform decision making. In application, they are structured around natural history of the health event under study. Such natural history is based on patient experience to describe the risks, different health states and progressions overtime.

The source of inputs to populate the models is often an issue for discussion. Outputs from quantitative research have been traditionally used to populate model-based economic evaluations. For example, using a unique administratively linked health care data, outputs from microeconometric modelling and analysis of the relationship between a broad range of socioeconomic, environmental, behavioural and biological risk factors, and health outcome (including mortality) have been used to populate models for cost-effectiveness analyses for number of diseases, including obesity and type II diabetes. These analyses provide evidence-based support for interventions to reduce health inequalities.  The role of qualitative research in informing model-based health economic evaluations is largely unknown.

Towards qualitative model-based health economic evaluations

Exclusive use of outputs from quantitative research to populate model-based economic evaluations have its limitations. A qualitative model-based health economic evaluation is one in which outputs from qualitative research form the inputs to populate the model.

Mixed method designs show that traditions of qualitative analytical methods are as rich as those of quantitative methods. There are rigorous and widely accepted procedures for study design, sampling, data collection and data analysis in qualitative research which may permit their adaptation to a health economic modelling framework.

Specifically, qualitative research has methods to tap from, including interviews and focus groups to explore individual knowledge and experiences, and ethnographic to observe and interact study participants in their real-life environment. They also include site visits to observe the socioeconomic and environmental factors, and review of records and other documents. Analytic techniques such as content analysis, thematic analysis, and in-depth case studies are used to analyse qualitative data.

Moreover, issues such as sampling is adequately considered in qualitative research. Sampling entails the process of selecting a portion of documents, manuscripts, archives, etc, to represent the entire population of interest. The sample size is less of a serious problem in as much the sample is adequate and appropriate. The qualitative researcher knows when data saturation is reached.

Rigorous application of qualitative methods to inform health economic evaluation models provides richer information and in-depth understanding of findings than applying only the traditional quantitative methods. A qualitative model-based economic evaluation is in line with the mixed-method approach often emphasised by funding streams. It is compatible with the patient public involvement in health care and social care research. More broadly, the approach will strengthen the capacity of research teams as well as collaborative efforts amongst RDS advisers, thereby improving quality of applications submitted for funding.

Despite these strengths, it is not suggested that qualitative research replace quantitative methods in economic evaluations. Where relevant, teams may consider research designs around mixed-method that incorporate qualitative health economic evaluation component. How to put this approach into practice is a subject for further discussion.

If you are preparing an application to NIHR or any other nationally competitive, peer-reviewed health and social care funder, do get in touch with your local RDS. We have experts in a range of different methodologies and approaches and will work with you to perfect your research design and your funding application, whatever the topic or design you may require.

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