In cost utility analyses, health outcomes are measured using Quality Adjusted Life Years (QALYs) which combine quality of life with length of life. The quality of life (QoL) component of the QALY is measured using a single index value, a Health State Utility (HSU) ranging from 0 (equivalent to death) to 1 (full health).
This HSU value is an important part of determining the cost effectiveness of a drug and in turn influences the decision making process of many Health Technology Agency (HTA) bodies, including National Institute of Health and Care Excellence (NICE). NICE assess the benefit of interventions in terms of cost to the NHS per QALY gained from a new intervention (i.e. the number of additional QALYs gained from the new intervention and the extra cost in £GBP).
The 2016 report from the Measurement Of Health State Utility Values For Economic Models In Clinical Studies ISPOR task force outlines a variety of options for the collection of HSU estimates for economic models. Although the report focuses on the collection of HSU data in clinical trials, the authors recognise that the design of a trial can influence the quality and usefulness of the data. They give the example that particular data for health states required for the model can be difficult to capture in a clinical trial setting, for example rare adverse events or long term treatment outcomes.
In the event that HSU data cannot be captured in a clinical trial setting, the ISPOR task force report outlines other possible methodologies: observational ('Real World') studies, review of published estimates, early access schemes and vignette studies.
pH Associates have a long history of including patient reported outcome measurement in Real World studies, including QoL assessment for HSU calculation. These studies typically begin with a review of the published literature to identify any HSU values which may already be published, in line with the recommendations from the ISPOR task force.
The two Real World study types outlined in the ISPOR task force report mirror those commonly conducted by the pH Associates team to collect QoL data; cross-sectional surveys and prospective observational studies at clinical sites. The authors discuss the advantages of cross-sectional surveys: they are quick and cost-effective to run, more discreet for collecting sensitive data and can use a variety of methodologies to recruit patients (including the examples given in the task force report: patient advocacy groups, social media and recruitment panels).
These alternative recruitment methodologies offer greater flexibility when recruitment through clinical sites is not appropriate or feasible. The authors note the main limitation of this methodology is the potential lack of accurate and verified reporting of clinical variables which enable patients to be categorised into health states. Although a relevant concern, pH Associates, have addressed this issue in previous studies by gaining patient consent to obtain the required clinical data directly from their clinician. In turn, prospective observational studies offer the potential advantage of enabling the collection of complex clinical data directly from patient medical records alongside HSU data.
The authors of the ISPOR task force report highlight some of the difficulties with the running of Real World studies, including a possible lack of engagement from clinical sites resulting in slow data collection.
The authors suggest that this can be overcome through careful site selection and engagement with medical specialists; in pH Associates' experience these two factors along with the design of a clear and concise protocol contribute to the success of a patient-reported observational study.
The ISPOR task force report concludes that "The quality of HSU estimates is critical to the decisions being made by HTA, pricing, and reimbursement authorities that affect patients' access to new treatments, physicians' ability to use them, and the return that manufacturers are able to realise on their investment in developing new products1". pH Associates' expertise in rigorous real world study design ensures the highest quality observational data, including quality of life and healthcare resource use data, which ultimately benefits patients through having access to the most appropriate medicines.
- National Institute for Health are Care Excellence (NICE). The guidelines manual. November 2012. Accessed: https://www.nice.org.uk/guidance/pmg6/resources/the-guidelines-manual-pdf-2007970804933
- Wolowacz SE, Briggs A, Belozeroff V, et al. Estimating health-state utility for economic models in clinical studies: an ISPOR good research practices task force report. Value in Health. 2016; 19(6):704-719. Accessed: https://www.ispor.org/Estimating-Health-State-Utility-Economic-Models-Clinical-Studies-guidelines.pdf
pH Associates are experts in the design and delivery of Real World data projects, including the collection of patient reported outcome data and HSUs in the Real World. For more information on collecting HSU data in the real world, or to discuss your data needs, please contact:
Catherine Bottomley, Associate Director at pH Associates via email: CatherineBottomley@phassociates.com
Angela Rylands, Patient Centred Outcomes Consultant at pH Associates via email AngelaRylands@phassociates.com