Asthma effects 5.4 million people in the United Kingdom. It is a chronic respiratory condition defined as frequent episodes of breathlessness, chest tightness and wheezing. An asthma attack is the progressive worsening of these symptoms, and can lead to increased healthcare resource use and reduced quality of life. It can be a costly disease, with over £1 billion of direct costs in England and Wales and over £130 million spent in Scotland.
Patient reported outcome measures (PROMs) can be used to measure quality of life, but it is currently not clear which preference-based measures are more appropriate for asthma. In most studies, quality of life is measured by PROMs at particular time points, such as baseline and 12 months, however an asthmatic episode may occur in between these time points due to the unpredictable nature of these events. Therefore, the loss in quality of life associated with an episode may not be fully captured. Alternatively, an event could occur at 12 months. This may result in an underestimation of quality of life, measured by the area under the curve technique.
Consequently, this thesis explored quality of life in acute asthmatics. Firstly, a systematic review explored the cost effectiveness of non-pharmacological asthma management interventions and the methodologies used to estimate costs and outcomes in the included studies. Secondly, a prospective cohort study estimated the loss in quality of life associated with an asthma-related crisis event (A&E attendance or hospital admission) using PROMs. Thirdly, the preference-based measures from the cohort study data set were compared using psychometric techniques.
This thesis has indicated that largest decreases in quality of life occurred during the first four weeks from the crisis event for all PROMs considered. The EQ-5D-5L and the AQL-5D had better psychometric performance compared to the other preference-based measures