Exploring patient, practitioner and general population preferences towards diagnostic tests for cancer (PhD)

Introduction

Availability of diagnostic tests within GP surgeries may be one way to triage patients and expediate early cancer diganosis, but it is unclear to what extent such diagnostic strategies are preferable to those currently available. Diagnostic procedures use different health system resources and incur different risks such as diagnostic accuracy and potential complications, leading to differences in costs and patient burden. These differences suggest decisions between diagnostic tests require a trade-off between the harms and benefits of each procedure.

This project will develop a set of choice based experiments to explore the preferences of patients, practitioners and the general public towards different diagnostic test strategies and assess the risk-benefit trade-offs.

Aims & objectives

• To critically appraise the current evidence relating to the use of discrete choice experiments (DCE) to estimate preferences in the field of cancer
• To identify any potential attributes of a diagnostic test that may affect preferences towards different tests through qualitative research
• To assess the relative weights and willingness to make trade-offs between benefits and harms of different diagnostic tests across three different populations: general population, patients, GPs
• To explore some of the methodological challenges related to the elicitation of preferences for the risks associated with diagnostic tests for cancer

Methodology

The early stages of this project will combine systematic reviews with qualitative research in order to critically analyse existing research on preferences towards cancer testing and design the survey used to elicit preferences in the later stages of the project.

The primary method used will be a series of discrete choice experiments (DCEs). DCEs are a quantitative method commonly used in health economics to elicit individual preferences and trade-offs between the perceived risks and benefits of interventions.

Outputs & impact

The primary outcomes of this project will be the relative importance of common characteristics of diagnostic tests and estimations of demand for different diagnostic tests currently available in primary and secondary care. Considering the willingness to trade between the risks and benefits of diagnostic tests by key stakeholders is important when making decisions about service delivery. Understanding the preferences towards diagnostics tests may be use to guide future practice and guidelines, for example, public preferences regarding key diagnostic issues such as over-diagnosis, false-positives and procedural complications may have important implications for investigative thresholds and earlier access to diagnostic testing.

Next steps

In the upcoming months, a series of focus groups with a sample from the target populations will be run in order to identify any potential attributes of a diagnostic test that may affect preferences. This information will be elicited using best-worst scaling and will be used to design the survey instrument used in the discrete choice experiment.

Publications

• Hall R, Medina-Lara A, Hamilton W, Spencer A. Attributes Used for Cancer Screening Discrete Choice Experiments: A Systematic Review. Patient (2021). doi: 10.1007/s40271-021-00559-3
• Hall R, Medina-Lara A, Hamilton W, Spencer A. Correction to: Attributes Used for Cancer Screening Discrete Choice Experiments: A Systematic Review. Patient (2021). doi: 10.1007/s40271-021-00562-8
• Hall R, Medina-Lara A, Hamilton W, Spencer A. Women’s priorities towards ovarian cancer testing: a best–worst scaling study. BMJ Open (2022); 12:e061625. doi: 10.1136/bmjopen-2022-061625