Syk 2013.
| Methods | Multicentred, open‐label, parallel RCT comparing a FeNO‐guided strategy versus usual care to adjust anti‐inflammatory treatment to improve asthma‐related QoL and asthma symptoms whilst reducing asthma exacerbations in atopic participants with asthma in primary care | |
| Participants | 165 participants completed the study from 187 randomised. FeNO group N = 87, mean age 40.9 (SD 11.8), 48 males, 39 females. Control group N = 78, mean age 41.1 (SD 12.9), 46 males, 32 females. They attended 1 of 17 primary healthcare centres in 7 different autonomous healthcare regions in Sweden. Inclusion criteria: aged 18 to 64 years, physician's diagnosis of asthma, prescribed ICS for > 6 months, confirmed IgE sensitisation to ≥ 1 major airborne perennial allergen (dog, cat, or mite). Exclusion criteria: pregnancy or breastfeeding, participation in another study, unstable asthma, smokers, solely on montelukast or in combination with budesonide equivalent dose 0 to 400 mcg |
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| Interventions | Participants were seen at enrolment, baseline (2 to 4 weeks later), month 2, month 4, month 8, and month 12 (final visit). FeNO, ACT, and registration of exacerbations were undertaken at each visit. mAQLQ and GQLI were attended at baseline, month 4, and month 12 only. FeNO group: Treatment was adjusted according to a FeNO algorithm and 6 fixed treatment steps. Control group: Treatment was adjusted according to usual care including patient‐reported symptoms, SABA use, physical examination, and lung functions results. |
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| Outcomes | Primary outcome: change in mAQLQ score during the study. Secondary outcome: changes in ACT score, exacerbation frequency, lung function, generic QoL score, and overall medication use |
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| Notes | Funding: This study was funded by the Stockholm county council (PickUP), Centre for Allergy Research, Karolinska Institute, and the Research Foundation of the Swedish Asthma and Allergy Association. Support was also received from Aerocrine AB (NIOX MINO instruments), Phadia AB (ImmunoCAP Rapid), Meda AB (Buventol Easyhaler), and MSD Sweden (small grant) | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Prepared by the study coordinator outside the primary health care centre. However, unclear how sequence was generated |
| Allocation concealment (selection bias) | Low risk | Envelopes used in lottery randomisation |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Open label. FeNO analyser screen was covered for control group, therefore study staff member nor participant knew the result. However, the FeNO analyser screen was not covered in FeNO group |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | Regarding FeNO as the FeNO group was not blinded to FeNO results which could influence their symptom scores |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All outcome data reported |
| Selective reporting (reporting bias) | Low risk | The named outcomes were well reported in the paper and the study protocol was prospectively registered. Additional data were provided by study authors |
| Other bias | Unclear risk | One of the authors (Alving K) was an employee and stock holder of Aerocrine (manufacturer of FeNO analysers) |
ACT: Asthma Control Test AQLQ: Asthma Quality of Life Questionnaire ATS: American Thoracic Society BBA: biomarker‐based adjustment FeNO: fractional exhaled nitric oxide FEV1: forced expiratory volume in 1 second GINA: Global Initiative for Asthma GQLI: Göteborg Quality of Life Instrument ICS: inhaled corticosteroids IgE: immunoglobulin E ITT: intention‐to‐treat LABA: long‐acting beta‐agonist mAQLQ: mini‐Asthma Quality of Life Questionnaire QoL: quality of life PABA: physician assessment‐based adjustment PEFR: peak expiratory flow rate RCT: randomised controlled trial SABA: short‐acting beta‐agonist SBA: symptom‐based adjustment SD: standard deviation