OBJECTIVES: To assess the effectiveness of oral or intranasal aspirin desensitisation, as monotherapy or as adjunctive therapy, in adults with NSAID-exacerbated respiratory disease.

SEARCH METHODS: The Cochrane Ear Nose and Throat (ENT) Information Specialist searched the Cochrane ENT and Airways Trials Registers; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; International Clinical Trials Registry Platform and additional sources for published and unpublished trials. The date of the search was 10 February 2023.

SELECTION CRITERIA: Randomised controlled trials that compared ATAD with placebo were eligible. We included studies of adults with NSAID-exacerbated respiratory disease (i.e. intolerance to NSAID established, e.g. by aspirin challenge test), with chronic rhinosinusitis or asthma, or both. Participants had to be followed up for at least three months.

DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. The primary outcomes were health-related quality of life, asthma control, and significant serious and non-serious adverse events. The secondary outcomes were changes in airway assessments, nasal endoscopy score, medication use, symptom scores, and chronic rhinosinusitis and asthma exacerbations (description of exacerbation for which systemic corticosteroid or sinus surgery was needed). We used the GRADE approach to rate the certainty of the evidence.

MAIN RESULTS: We included five studies with a total of 211 participants (146 analysed). All studies compared oral ATAD at different dosages with placebo and were performed in tertiary care centres. All participants had a diagnosis of chronic rhinosinusitis with nasal polyps. In four studies, participants also had a confirmed diagnosis of asthma and two studies reported that participants had previous surgery for nasal polyps. Outcomes were analysed at six and 36 months follow-up. However, only one study reported data for 36 months follow-up. All but one study reported source of funding. Mid-term follow-up (six months, ATAD versus placebo) ATAD may improve health-related quality of life, assessed with Sino-Nasal Outcome Test (SNOT) scores (mean difference (MD) -0.54, 95% confidence interval (CI) -0.76 to -0.31; 3 studies, 85 participants; minimum clinically important difference (MCID) 9.0 points for total score; low-certainty evidence). In this analysis, SNOT-22 scores were divided by 22 and SNOT-20 scores were divided by 20. The mean reduction (11.9 points) in SNOT score (based on SNOT-22) is larger than the MCID. It is uncertain if asthma control may be improved after ATAD. Asthma control was measured using the Asthma Control Test (ACT) in one study and the Asthma Control Questionnaire (ACQ) in another study, so data were not pooled. The MD on the ACQ was -2.00 (total score 0 to 6) (95% CI -4.30 to 0.30; 1 study, 15 participants; MCID 0.5 points; very low-certainty evidence). The MD on the ACT was 5.90 (total score 5 to 25) (95% CI 2.93 to 8.87; 1 study, 30 participants; MCID 3 points; very low-certainty evidence). All but one study reported on adverse events. Seven participants in the active treatment group developed a gastrointestinal disorder and dropped out (129 participants, very low-certainty evidence). We are uncertain of the effect of ATAD on nasal airflow, measured by peak nasal inspiratory flow scores (MD 32.90 L/min, 95% CI -12.44 to 78.24; 1 study, 15 participants; very low-certainty evidence). It is uncertain if the dosage of intranasal or inhaled corticosteroids may be reduced with ATAD (inhaled corticosteroids: -1197.60 µg, 95% CI -1744.93 to -650.27; intranasal corticosteroids: -120.50 µg, 95% CI -206.49 to -34.51; 1 study; 15 participants; very low-certainty evidence). Symptom scores may not differ between ATAD and placebo, but the evidence is very uncertain (sneezing: MD -0.70, 95% CI -1.45 to 0.05; smell: MD -2.20, 95% CI -4.74 to 0.34; nasal blockage: MD -0.90, 95% CI -1.90 to 0.10; 1 study, very low-certainty evidence). No study assessed nasal endoscopy at this time point. Long-term follow-up (36 months, ATAD versus placebo) ATAD may improve quality of life, as measured with the Rhinosinusitis Disability Index (RSDI) score (MD-18.10, 95% CI -32.82 to -3.38; 1 study; 31 participants; low-certainty evidence). ATAD may result in little to no difference in the size of nasal polyps (MD -1.20, 95% CI -2.72 to 0.32; 1 study, 31 participants; very low-certainty evidence). No adverse events were reported in either group over the total study period of 36 months (1 study; 31 participants; very low-certainty evidence). Data on peak nasal inspiratory flow, changes in dosage of inhalation or intranasal corticosteroids and symptom scores were not reported at this time point.