Candidate variables for prediction of risk of asthma exacerbation based on Box2-2B of the GINA 2014 report and their operationalisation* for the predictor analysis
| Risk factor for exacerbations (GINA 2014) | Operationalisation in ACCURATE database | |
|---|---|---|
| 1 | Uncontrolled asthma symptoms | Asthma Control Questionnaire (ACQ-5; continuous) |
| 2 | High SABA use | ≥1 puff a day during the last 7 days before baseline |
| 3 | Inadequate ICS: not prescribed | No ICS prescribed at baseline |
| 4 | Inadequate ICS: poor adherence | Medication Adherence Rating Scale (continuous) |
| Inadequate ICS: incorrect inhalation technique | Not available | |
| 5 | Low FEV1 | Prebronchodilator FEV1% predicted (continuous) |
| 6 | Major psychological problems | Self-reported use of antidepressants |
| 7 | Major socioeconomic problems | Income (ordinal) |
| 8 | Exposures: smoking | Current smoking |
| 9 | Exposures: allergen exposure if sensitised | Positive-specific IgE titres to house dust mite and/or grass and/or birch pollens† and/or IgE positivity to cat or dog combined with ownership |
| 10 | Co-morbidities: obesity | Body mass index (continuous) |
| 11 | Co-morbidities: rhinosinusitis | Self-reported complaints of chronic sinusitis |
| 12 | Co-morbidities: confirmed food allergy | Self-reported food allergy |
| Pregnancy | Not available | |
| Sputum/blood eosinophilia | Not available | |
| 13 | Ever intubated or intensive care | Self-reported hospitalisation (ever) for asthma |
| 14 | ≥1 severe exacerbation in last 12 months | Self-reported steroid burst/hospital admission for asthma in the previous year |
*Operationalisation of some variables differed from the GINA report; FeNO was also assessed in one of the models (values were analysed as dichotomous variables unless stated otherwise).
†Exposure to each of these allergens can be assumed in the Netherlands.
ACCURATE, Asthma Control Cost-Utility RAndomized Trial Evaluation; ICS, inhaled corticosteroids; SABA, short-acting β2-agonist.