Summary of findings 1. Intranasal steroids compared to no intervention for the prevention of persistent post‐COVID‐19 olfactory dysfunction.
| Intranasal steroids compared to no intervention for the prevention of persistent post‐COVID‐19 olfactory dysfunction | ||||||
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Patient or population: adults with olfactory dysfunction for < 4 weeks following COVID‐19 infection Setting: one hospital in Egypt Intervention: intranasal corticosteroid spray Comparison: no intervention | ||||||
| Outcomes | Anticipated absolute effects*(95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with no treatment | Risk with intranasal steroids | |||||
| Self‐rated presence of normal olfactory function Assessed with: score of 10 on a visual analogue scale (rated 0 to 10, where 10 = "completely normal smell sensation")1 Follow‐up: ≤ 4 weeks |
Study population | RR 1.19 (0.85 to 1.68) | 100 (1 RCT) |
⊕⊝⊝⊝ very low2,3 | — | |
| 520 per 1000 | 619 per 1000 (442 to 874) | |||||
| Serious adverse effects | No studies reported on this outcome. | |||||
| Self‐rated change in sense of smell Assessed with: numeric rating scale (0 to 10, higher = better) Follow‐up: ≤ 4 weeks |
Change in sense of smell was not reported, only endpoint data. One study reported a median sense of smell score of 10 (IQR 9 to 10) in those receiving intranasal steroids and a median score of 10 (IQR 5 to 10) in those who did not receive steroids at 3 weeks' follow‐up (P = 0.16). |
— | 100 (1 RCT) | ⊕⊝⊝⊝ very low2,4 | — | |
| Prevalence of parosmia | No studies reported on this outcome. | |||||
| Change in sense of taste | No studies reported on this outcome. | |||||
| Disease‐related quality of life | No studies reported on this outcome. | |||||
| Other adverse effects | No studies reported on this outcome. | |||||
| *The risk in the intervention group (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; IQR: interquartile range; RCT: randomised controlled trial; RR: risk ratio; VAS: visual analogue scale | ||||||
| GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
1We have assumed that individuals who reported a score of 10 on the VAS were included as those who reported "completely normal smell sensation".
2Serious risk of bias as this was an unblinded study, and the outcome was self‐assessed by the participants.
3Very serious imprecision due to the very small sample size, which does not reach the optimal information size (< 400 participants), and the wide confidence intervals, which range from potential harm to potential benefit.
4Very serious imprecision due to the very small sample size, which does not reach the optimal information size (< 400 participants), and because no effect size or confidence interval could be calculated.