Summary of findings for the main comparison. MHRV compared to placebo for asthmatics with sensitivity to house dust mite.
| MHRV compared with placebo for asthmatics with sensitivity to house dust mite | ||||||
| Patient or population: asthmatics with sensitivity to house dust mite Settings: Community Intervention: MHRV Comparison: placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | MHRV | |||||
|
Change in Morning PEF after 12 months (% predicted) Follow‐up: 12 months |
Change of ‐7% on placebo | Change of +6.4% on MHRV | MD 13.59 % (‐2.66 to 29.84) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
|
Change in Evening PEF after 12 months (% predicted) Follow‐up: 12 months |
Change of ‐12% on placebo | Change of +12% on MHRV | MD 24.56 % (8.97 to 40.15) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
|
Change in FEV1 after 12 months (% predicted) Follow‐up: 12 months |
Change of +1.8% on placebo | Change of +1.0% on MHRV | MD 1.32 % (‐2.55 to 5.19) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
|
Quality of life SGRQ Scale from 0 to 100 (0 on the scale is better) Follow‐up: 12 months |
Change of ‐2.1 units on placebo | Change of ‐5.2 units on MHRV |
MD ‐2.83 units (‐7.82 to 2.16) |
100 (1 study) |
⊕⊕⊕⊝ moderate1 | |
| Exacerbations needing oral steroids Follow‐up: 12 months | 362 per 1000 | 228 per 1000 (111 to 413) | OR 0.52 (0.22 to 1.24) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
| Exacerbations needing ED visit Follow‐up: 12 months | 43 per 1000 | 76 per 1000 (14 to 319) | OR 1.84 (0.32 to 10.52) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
| Exacerbations needing hospitalisation Follow‐up: 12 months | 85 per 1000 | 8 per 1000 (0 to 138) | OR 0.09 (0 to 1.72) | 100 (1 study) | ⊕⊕⊕⊝ moderate1 | |
| *The basis for the assumed risk is the mean control group risk. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; OR: Odds ratio; | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1 Single study with wide confidence interval MD: mean difference MHRV: mechanical heat recovery ventilation system OR: odds ratio PEF: peak expiratory flow