Factors affecting patients' decision to adjust treatment; secondary analysis of a randomised trial of treatment optimisation in patients with severe asthma

Why do some patients with severe asthma not follow healthcare provider (HCP) advice to adjust treatment? We explored possible barriers when adjusting asthma treatment in a secondary analysis of data from a randomised, controlled, single-blind (study participant), multi-centre, parallel group 48-week clinical study comparing biomarker directed treatment adjustment to standard care in severe asthma. The main outcome measure was patient choice not to follow HCP advice to adjust asthma treatment. Of 1572 treatment advisories (301 subjects) instructions were followed in 1,377 cases (87.6%). Patients were more likely to follow advice to remain on current treatment (96.7%) than to either reduce (70.3%) or increase (67.1%) their treatment, with 64% of patients following all treatment advice. Multivariate analysis showed belonging to an ethnic minority group (OR: 3.10; 95% CI: 1.68, 5.73) and prior study medication change (≥2 OR: 2.77, 95% CI: 1.51, 5.10) were associated with failure to follow treatment advice. Emergency room attendance (<1yr) (OR: 0.54, 95% CI: 0.32, 0.92) was associated with following treatment advice. The largest effect was seen with transition onto or off oral corticosteroids (OR: 29.28; 95% CI: 16.07, 53.36) vs. those requested to maintain treatment. Study centre was also an important determinant. Factors such as minority ethnic group and different patient behaviour in specialist clinical centres will require further focussed studies to explore the underlying mechanisms. These findings have implications for generalisability for models of care in severe asthma.