Powell 2011.
| Methods | Randomised, parallel, double‐blind controlled trial of FeNO‐guided therapy in 2 antenatal clinics. Expectant mothers were randomised to a FeNO‐guided algorithm for adjusting asthma therapy or a clinical‐guideline algorithm. The randomisation was stratified by maintenance budesonide dose (< 800 ug per day or > 800 ug per day). The participant, research assistant, and investigators were blinded to the randomisation group. There were 17 dropouts, 11 in the FeNO group and 6 in the control group. The women were reviewed monthly until delivery |
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| Participants | 242 women were recruited, of which 220 were randomised. FeNO group N = 111; mean age 28 (range 27 to 29). Control group N = 109; mean age 29 (range 28 to 30). Attending antenatal clinics at 2 hospitals in New South Wales, Australia. Inclusion: Non‐smoking pregnant women (aged > 18 years) with asthma using inhaled therapy and attending the clinic. They were recruited at between 12 and 20 weeks' gestation |
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| Interventions | The women were seen monthly until they delivered. Clinical‐symptom data, ACT score, present treatment, FeNO, and FEV1 were collected at each visit. ACT score, FeNO levels, and current treatment were sent to the algorithm keeper via facsimile for treatment recommendations. FeNO group: Sequential process, first FeNO concentrations used to adjust ICS dose, and second ACT score used to adjust the LABA dose. Clinical group: Based on asthma control using Juniper ACT with cutoff points defined as: well‐controlled asthma (ACT < 0.75), partially controlled asthma (0.75 to 1.50), and uncontrolled asthma (> 1.5) |
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| Outcomes | Primary outcome: Total number of asthma exacerbations (i.e. moderate and severe). Secondary outcomes: QoL, asthma treatment, and fetal outcomes |
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| Notes | Funding: This study was funded by the National Health and Medical Research Council of Australia | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Randomisation was completed in blocks of 4 with an equal treatment allocation ratio |
| Allocation concealment (selection bias) | Low risk | A statistician used computer‐generated random number list for randomisation and stratified by maintenance budesonide dose at visit two ( < 800 ug per day or ≥ 800 ug per day) |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Double blind. The use of an algorithm keeper was not masked but was not directly involved in the care or assessment of the participant |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Assessment of asthma control was made by investigators who were blinded to the participant's randomisation group. The algorithm keeper received the ACT score, FeNO level and current treatment via facsimile and applied the appropriate algorithm and sent the treatment recommendation to the research assistant who informed the participant |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All outcome data presented |
| Selective reporting (reporting bias) | Low risk | All data presented |
| Other bias | Unclear risk | Nil information provided in the published article regarding success in obtaining FeNO on each visit |