High health gain patients with asthma: a cross-sectional study analysing national Scottish data sets.

Studies have shown that a small proportion of patients have particularly high needs and are responsible for disproportionally high disease burden. Estimates suggest that 2-5% of patients are high users of healthcare for their health gain. Such patients in Scotland are referred to as high health gain (HHG) patients. We wanted to investigate if there were HHG individuals with asthma in Scotland. We analysed data from the Scottish Health Survey (2010-11), and primary and National Health Survey (NHS) secondary healthcare and administrative data sets (2011-12). In all, 1,379,690 (26.0%) and 836,135 (15.8%) people reported to have ever had and currently have symptoms suggestive of asthma, respectively; 369,868 (7.0%) people reported current symptomatic clinician-diagnosed asthma. 310,050 (5.6%) people had clinician-reported-diagnosed asthma; there were 289,120 nurse consultations, 215,610 GP consultations, 9235 accident and emergency visits (0.2% people), 8263 ambulance conveyances (0.2% people), 7744 inpatient episodes (0.1% people), 3600 disability allowance claims (0.1% people), 187 intensive care unit (ICU) episodes and 94 deaths from asthma. From our study a maximum of about 9.4% of asthma patients (n = 29,145), which is 0.5% of the Scottish population, and from the National Review of Asthma Deaths' estimate (10% hospitalised), a minimum of nine people had severe asthma attacks that needed acute hospital attendance/admission. We found that although a high proportion of the Scottish population had symptoms suggestive of asthma and clinician diagnosed asthma, only a small proportion of asthma patients experienced exacerbations that were severe enough to warrant hospital attendance/admission in any given year. Developing risk prediction models to identify these HHG patients has the potential to both improve health outcomes while substantially reducing healthcare expenditure.