The Salford Lung Study in Asthma (SLS Asthma) was a multicentre, randomised, controlled, open-label trial that assessed initiating once-daily, single-inhaler fluticasone furoate/vilanterol (FF/VI) 100 μg/25 μg or 200 μg/25 μg versus continuing usual care. A subgroup (n = 400) from SLS Asthma was enrolled in this exploratory, interview-based follow-up study. Quantitative and qualitative data were collected via questionnaires. The primary objective was to capture patient-centred outcomes (symptom experience, quality of life [QoL], disease management behaviours) and patient experience. Secondary objectives were to assess the correlation of patient-reported outcomes with pre-defined variables from SLS Asthma (Asthma Control Test [ACT] score). The follow-up sample was representative of the SLS Asthma population; half reported asthma improvement during the study. Breathlessness was the most likely symptom to improve (47.8% of patients reported improvement). Most patients reported ‘no change’ in overall QoL (57.5%) and daily life domains (functioning 66.3%, activities 68.3%, relationships 86.8%, psychological 68.5%). Functioning was reported as the most frequently improved domain (29.8% of patients). Perceived improvement in asthma control (42.5%) and confidence (37.3%) was frequent. ACT responders (defined as patients achieving an ACT score ≥20 and/or an increase of ≥3 in ACT score from baseline at Week 52) were more likely to report asthma improvement (88.7% of patients reporting ‘a lot’ of improvement) than non-responders. Patients’ asthma experiences generally improved during SLS Asthma. Clinical improvements were often associated with perceived improvement by patients, particularly among ACT responders.