Results from the first CHESS study were published in July 2017 (O’Hara et al. Orphanet Journal of Rare Diseases (2017) 12:106). The study investigated the burden of illness (BOI) for haemophilia patients and has been instrumental as a source of health economic evidence in advocating for access for these patients to new genetic advances in treatment.

Important features of the CHESS design included valuable descriptive, point in time analysis that included patient contributed data alongside physician-reported clinical outcome information and physician validated diagnosis. The study is undertaken by a partnership founded on the principle of public and patient involvement and engagement (PPIE) that included The Haemophilia Society, University of Chester (Faculty of Health and Social Care) and HCD Economics Ltd.

A long-term objective with the continuing CHESS research programme is to address the following research objectives.

  • to be able to provide long-term analysis, to enhance current point in time analysis as reported in the CHESS literature to date (eight peer review publications 2017 – 2021, with a number pending publication, currently in peer review)
  • to observe evolutionary characteristics at the patient level
  • to be able to strengthen the evidence base available to  advocacy efforts by investigating  relationships between variables, detect developments or changes in the characteristics of the target population at both the aggregate and the individual level and exploring potential causal links
  • Report findings that may be used to make inference and add to the available resource utilisation and socio-economic evidence base and that links patient outcomes and impact with resource utilisation

The CHESS design partnership is now entering the third and fourth wave of this continuing research programme. The study continues to adhere to its original primary aim to determine the socio-economic burden and Health-related Quality of Life (HRQoL) of male haemophilia adult patients of all severities. By securing consent from a subset of the cross-sectional population, CHESS III and IV will observe 12 months retrospective cost and healthcare utilisation data, offering a longitudinal perspective on this subset of the CHESS population who will be participating in waves II to IV. The design will study this population’s 12 months retrospective socio-economic and clinical outcomes, thus enhancing the cross sectional HRQoL data with patient-important socio-economic evidence.

The Economic and Social Research Council states (on the UCL website*) ‘the value of longitudinal studies increases as each sweep builds on what is already known about the study participants. This means that in the case of CHESS III and IV, the accrued data pool will contain far more detailed information than could be collected through conducting each wave as a one-off survey.

CHESS Longitudinal data collection will allow haemophilia researchers to build up a more accurate and reliably ordered account of the key events and experiences in the life of the haemophilia patient. Understanding the order in which events occur is important in exploring causality.

Many of the advantages of longitudinal studies relate to the analytic questions their data can help address. For example, longitudinal data help with including understanding dynamic rather than static concepts. This is important for understanding how people move from one situation to another. By building up detailed information over time, longitudinal studies are able to paint a rich and accurate picture of participants’ lives. Longitudinal data also allows the haemophilia community to assess the time-related characteristics of particular events or circumstances (that is, their duration, frequency or timing). Finally, the CHESS longitudinal data will be much richer in detail, which allows analysts to take a wide array of background characteristics or control variables into account. This provides additional tools to mitigate the risk of ‘unobserved heterogeneity’ or ‘confounding’.

CHESS III and IV will be seeking to collaborate with the haemophilia research community, including pharmaceutical partners interested in exploring the longitudinal data and participating in publication of results. For further information on the CHESS research programme, please contact Enrico Ferri Grazzi at HCD Economics Ltd.

Enrico Ferri Grazzi, MSc, , M: +44 7496137782