This is a real-life pragmatic non-randomised study to explore the impact of mepolizumab on the emotional and affective outcomes of patients with severe eosinophilic asthma and their partners. It will be conducted in two quantitative stages (Phases 1 and 2) with an additional third qualitative component (Phase 3).

This longitudinal observational study will investigate the relationship between patients' asthma control and emotional states and quality of life in patients and their partners where patients have severe eosinophilic asthma. The study will consist of three phases.

Phase 1 In order to extend our pilot study findings and help inform the second stage, investigators will gather Geneva Emotional Wheel (GEW) data from 30 patients currently treated and benefitting from mepolizumab (Nucala®). This data will be compared to the GEW data investigators have already gathered from patients with severe asthma not receiving treatment with mepolizumab (Nucala®). This will provide timely data to support a publication on the GEW findings in severe asthma and allow the description of the impact of mepolizumab (Nucala®). In addition, it will help provide power calculations for a prospective study. Parallel assessment of quality of life (SGRQ and SAQ) and anxiety and depression (HADS) will be made to evaluate the relationship between GEW, SGRQ, SAQ and HADS scores.

Phase 2 In the second stage, investigators will conduct a prospective study of 45 patients newly prescribed mepolizumab (Nucala®) and their partners measuring participants' emotional composition before and 6 and 12 months after starting treatment. The choice of 60 has been based on likely power requirements but was adjusted to 45 based in Phase 1 results. Investigators will also compare the outcomes from the GEW with other standard outcome measures (HADS, ACQ, SGRQ, SAQ, BIPQ), to establish relationship between changes in these measures and changes in GEW scores, to evaluate the utility of the GEW. This will help determine if the GEW reflects changes in asthma control or whether it is reflecting improvements that the current established instruments do not recognise and allow us to quantify the magnitude of that effect. As these patients will receive mepolizumab as part of their clinical care for a year, whilst assessment of clinical efficacy is being established, investigators will gather data on oral steroid dependent exacerbations (severe exacerbations) during this year and relate to their historic exacerbation history in the year before. Evaluation will be made as to whether the 6-month improvement in GEW scores predicts impact of mepolizumab on exacerbation reduction over the first year of administration. In addition, improvements in the GEW will be explored in relationship to systemic inflammatory impact, with measures of blood eosinophils and serum inflammatory biomarkers (Olink inflammatory panel) at baseline, 6 months and 1 year.

Phase 3 Finally, in addition, investigators will conduct qualitative research in the form of semi-structured interviews with a sub-set of couples (20 couples or less if no new information emerges from the interviews) to gain a more detailed insight and identify common key aspects in their subjective experiences, quality of life and emotional processes before starting treatment and after being on treatment with mepolizumab for 6 months.

Inclusion Criteria:

Phase 1:

• Age 18 or over
• Having a diagnosis of severe eosinophilic asthma
• Currently on mepolizumab (Nucala®) treatment
• At least basic command of English
• Giving written informed consent

Phase 2 Patient eligibility Inclusion criteria

• Age 18 or over
• Having a diagnosis of severe eosinophilic asthma
• Scheduled to start mepolizumab (Nucala®) treatment
• At least basic command of English (for sub-study: conversational level of English that does not require a translator)
• Giving written informed consent
• Co-habiting with an intimate partner who is willing to participate in the study

Exclusion criteria

• Participated in Phase 1
• Currently on mepolizumab (Nucala®) treatment
• Major psychiatric disorder currently under treatment
• History of any major psychiatric disorder in the last 5 years, excluding depressive and anxiety disorders that can be included if treatment or change of treatment (including change in dose of medication) has not started within the last 6 months
• Any diagnosed severe comorbid chronic condition that, in the opinion of the patient's asthma physician, might impact on the patient's or partner's affective state (e.g. cancer, diabetes, heart failure, chronic liver disease, chronic kidney disease, autoimmune or neuro-degenerative disease).
• Partners only: diagnosis of severe eosinophilic asthma
• Death of spouse, main informal carer or first-degree family member within the last 3 months
• Current oral corticosteroid maintenance treatment

Partner eligibility Inclusion criteria

• Age 18 or over
• At least basic command of English (for sub-study: conversational level of English that does not require a translator)
• Giving written informed consent
• Partners: Co-habiting with an intimate partner who has severe eosinophilic asthma and is willing to participate in the study

Exclusion criteria

• Participated in Phase 1
• Major psychiatric disorder currently under treatment
• Participant self-reported history of any major psychiatric disorder in the last 5 years, excluding depressive and anxiety disorders that can be included if treatment or change of treatment (including change in dose of medication) has not started within the last 6 months.
• Participant self-reported any diagnosed severe comorbid chronic condition that, in the opinion of the patient's asthma physician, might impact on the patient's or partner's affective state (e.g. cancer, diabetes, heart failure, chronic liver disease, chronic kidney disease, autoimmune or neuro-degenerative disease).
• Diagnosis of severe eosinophilic asthma
• Death of spouse, main informal carer or first-degree family member within the last 3 months
• Current oral corticosteroid maintenance treatment

Phase 3:

Phase 3 is a qualitative study on a sample of couples from Phase 2 therefore the same exclusion criteria will apply as in Phase 2.

Patients with severe eosinophilic asthma on mepolizumab treatment (Phase 1) Patients with sereve eosinophilic asthma who are to start mepolizumab treatment and their partners ( Phase 2 and 3)

Only anonymised and aggregate data will be shared