Health State Utility Data in Cystic Fibrosis: A Systematic Review

Abstract

Introduction Cystic fibrosis (CF) is a life-limiting, hereditable condition, with the highest prevalence in Europe. CF treatments have led to improvements in clinical symptoms, disease management and decelerated disease progression. However, little is known about the health state utility (HSU) associated with CF disease states, adverse events, and changes in disease severity. Although HSU data have contributed to existing health economic modelling studies, a lack of such data have been highlighted. This systematic review aims to provide a summary of HSU-related research in CF and highlight related research gaps. Methods Online searches were performed in six databases and studies in any of the following categories were included: (1) estimation of HSUs in CF; (2) mapping studies between patient-reported outcome measures (PROMs) and HSUs; (3) economic evaluations on the management of CF that report primary HSU data; and (4) any CF clinical trial that reported HSU as an outcome. Results A total of 17 studies were reviewed, of which 12 provided HSU values for specific CF populations. The remaining five articles provided HSU data that were broken down by CF relevant health states, including lung transplantations, pulmonary exacerbation (PEx) events and forced expiratory volume in 1 s (FEV 1). Conclusion Current HSU data in CF are limited and there is considerable scope for further research, both in providing HSU values for CF and in investigating methods for HSU elicitation/evaluation in CF populations.

‘Mapping’ Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

“…Another systematic review on cystic fibrosis [67] identified only one study mapping from the CFQ-R onto EQ-5D-3L [15], which was consistent with our findings, and encouraged the development of future mapping studies to inform health economic modelling in this rare condition. Lastly, two systematic reviews [10,68] were identified in Cushing's syndrome and included the same two mapping studies [31,41] captured by our review.…”

A model-based economic analysis of the CFHealthHub intervention to support adherence to inhaled medications for people with cystic fibrosis in the UK

“…; (3) FEV 1 < 40% pred. ; (4) post-transplant; and; (5) death (Figure 1). During each model cycle, patients may remain in their current health state, transition to an improved or worsened health state or die.…”

“…Total QALYs are calculated as the sojourn time in each state weighted by state-specific utility scores, minus any IV-related QALY losses. The model includes costs associated with: (1) the CFHH adherence intervention; (2) health state resource use; (3) IV treatments (including inpatient stays, IV drugs, and consumables); (4) nebulizer devices; (5) nebulized therapies, and (6) transplantation.

Figure 1. Model structure. Note: Reproduced with permission from Wildman et al (11). Published by NIHR Journals Library.

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“…Whilst CF is a multisystem disorder, the upper and lower airways and digestive system are most commonly affected (2). Amongst other problems, people with CF are susceptible to bacterial lung infections and reduced lung function, which adversely impact on survival and health-related quality of life (HRQoL) (3;4). People with CF require ongoing preventative medications which are intended to preserve lung function and reduce the incidence of pulmonary exacerbations (5).…”

Future therapies for cystic fibrosis

“…Health technology appraisals by government bodies assess cost-effectiveness of new drugs, often using a cost per quality-adjusted life-year (QALY) in their deliberations. These economic evaluations require the use of health state utility values and the evidence for these in CF is sparse 29 . What monetary cost should be given to a longer or better-quality life is where controversy can arise, particularly when a new drug is not approved to be prescribed within a nation’s health care system.…”