Thesis Thursday: Olivia Ernstsson

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 Olivia Ernstsson who has a PhD from the Karolinska Institute. If you would like to suggest a candidate for an upcoming Thesis Thursday, get in touch.

Making use of patient-reported outcome measures in health care: the case of EQ-5D in the Swedish national quality registries
Niklas Zethraeus, Emelie Heintz
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Are PROMs used widely in routine care in Sweden?

I would like to say both yes and no. We used a specific case in this thesis – the case of the Swedish national quality registries (NQRs) – to better understand the use of PROMs in routine health care. Therefore, the findings are restricted to the specific target populations and interventions covered by the NQRs.

From an international perspective, the case of the Swedish NQRs is one of relatively few real-world examples of EQ-5D or other PROMs being widely implemented across different patient populations in routine health care. At the same time, at the start of this project we did not know to what extent the collected PROMs data were actually being used to improve health care or patient health. The first study included in this thesis largely contributed to our understanding of the use of EQ-5D, and to some extent also other PROMs, routinely collected in the Swedish NQRs. We found that EQ-5D data were used for assessing interventions, health economic studies, benchmarking, quality improvement, in quality indicators, and for consultations with individual patients. Still, a relatively large share of the NQRs (19/41) reported that the EQ-5D data were not used, or that they were unaware of whether data were used for these purposes. Overall, there is potential to make more use of PROMs data collected in routine health care in Sweden.

What data sets and methods did you use for your research?

The four studies differed with regard to the specific research question, design, population, data and materials, and methods used for analysis.

In the first study, we conducted an overview of how EQ-5D data are collected in the Swedish NQRs, and how the collected data are made available and used for follow-up, quality improvement, and decision-making. Information was collected through documents and through personal communication with representatives from the 41 registries.

In the second study, we used qualitative research methods to better understand how individuals think and reason when reporting and valuing their own current health, using EQ-5D-5L, EQ VAS, and an experience-based time trade-off (TTO) question. We recruited patients with type 1 diabetes to participate in individual think aloud interviews, and the interview data were analysed using qualitative thematic analysis.

The third and fourth studies were based on data from two Swedish NQRs: the Swedish Amputation and Prosthetics Registry (SwedeAmp) and the Swedish National Quality Registry for electroconvulsive therapy (Q-ECT). In the third study, we examined and compared the measurement properties of EQ-5D-3L and EQ-5D-5L in patients with a major lower limb amputation. We studied the feasibility (i.e., analysing missing data), distributional characteristics (e.g., ceiling and informativity), and convergent and known-group validity. Finally, in the fourth study, EQ-5D was applied as an outcome measure to assess a specific intervention. We examined the relationship between pulse width (i.e. a treatment modality) and health-related quality of life after ECT in patients with unipolar or bipolar major depression.

Is the EQ-5D a valid PROM in the specific conditions that you studied?

This is a very important question to address and a prerequisite for making use of PROMs data. We found that EQ-5D data were collected across more than 40 different patient populations. Although the research literature on the measurement properties of EQ-5D cover various populations, there is still a need to further explore the performance of the instrument in certain populations.

In one of the studies included in the thesis, our objective was to examine and compare the measurement properties of EQ-5D-3L and EQ-5D-5L in patients with a major lower limb amputation. In the SwedeAmp registry, EQ-5D and several disease-specific PROMs are collected and used in routine rehabilitation settings. The registry had changed from EQ-5D-3L to -5L, with the expectation that the increased number of severity levels and the changes made to the mobility dimension in EQ-5D-5L would improve the measurement of health in this population. From our analyses of the measurement properties, we found that the change from EQ-5D-3L to -5L was beneficial, as the 5-level version showed improved informativity and validity.

Did your qualitative work on the EQ-5D reveal anything unexpected?

Yes. First of all, I believe that the qualitative work, focusing on the patient perspective, was a very important piece for the thesis and for understanding the use of PROMs.

I asked the participants to complete the EQ-5D-5L descriptive system, EQ VAS, and an experience-based TTO question during the think-aloud interviews. Before, I expected the EQ-5D responses to be rather straightforward, and the TTO valuations to be more complex. However, the thoughts expressed by the interview participants showed that it can be challenging for the respondent to interpret questions and to report one’s own health. One interesting finding was the impact of wording in the questionnaires. For example, some participants expressed that health questionnaires often make them think more about their problems than they normally do.

It was interesting to see the wide variety of interpretations and operationalisations of questions. The common pattern I observed was that participants expressed the ways in which the experienced problems stopped them from doing the things they wanted to do. I think one of the most interesting findings was the way participants considered different aspects when completing the different assessments, for example by considering specific problems experienced in everyday life when completing the EQ-5D-5L descriptive system, and by considering the impact on others in the TTO assessment.

Additionally, one finding regarding the TTO assessment was that participants showed stronger reactions towards imagining being in ‘full health’ than imagining having only a few years left to live. Some interview participants expressed that the ‘full health scenario’ described in the TTO question was unrealistic.

How would you like to see PROMs used in the future, in Sweden and beyond?

The PROMs data collected in clinical registries and quality registries could play an important role in real-world evidence studies and for policy-making.

I would like to see use of PROMs data that are directly beneficial for those who take their time to report and register PROMs data in routine health care – patients and health care professionals. There are many potential benefits of using PROMs, both in the patient-clinician encounter and when being used for aggregate-level analyses. In addition, I think the purpose of measurement should be clearly communicated when data are collected in routine health care – in what ways will this information be useful for me or for others?

Although the overview showed several examples of use of EQ-5D data, we also found that a large share of the collected data is not being used for follow-up, quality improvement, or decision-making. There are different possible explanations for the limited use of data, and future studies could explore prerequisites and facilitators for making use of PROMs data collected in routine health care. I think it is important to consider all phases of the implementation; that the purpose of measurement should be clear from the start, and that the collection, analysis, visualisation, and use of data are in line with the specific purpose.

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  • Founder of the Academic Health Economists' Blog. Principal Economist at the Office of Health Economics. ORCID: 0000-0001-9470-2369

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