Hira and Singh [46] | 2009 | n=51 Patients referred to tertiary centre for treatment-refractory asthma | Cross-sectional | 24% had VCD Age 32.9±12.4 years 58% female IOS-positive in 58% of cases and 15% of controls
| Only considers glottic ILO diagnosed at rest |
Røksund et al. [2] | 2009 | n=151 cases and n=20 controls Patients with exertional dyspnoea consecutively referred to a tertiary clinic
| Cross-sectional | 75% had EILO Age 16.3±7.3 years 72% female Detailed description of laryngoscopic presentations
| Highly selected population |
Christensen et al. [21] | 2011 | n=98 (n=556 invited to participate) General population | Cross-sectional | 43% had EILO Age 19 (14–24) years Female/male odds ratio of having EILO was 3.41 79% supraglottic, 14% glottic, 7% mixed glottic and supraglottic 70% had verified airway hyperresponsiveness to methacholine Estimated prevalence of EILO in the general population: 7.6%
| Selection bias from 2-day work-up |
Nielsen et al. [6] | 2013 | n=88 Athletes referred to CLE in a tertiary asthma clinic | Case series | 35% had EILO Median (IQR) age 18 (11) years 77% female 43% had verified asthma
| Retrospective design Highly selected population |
Tilles et al. [103] | 2013 | n=143 Patients with EILO confirmed by post-exercise laryngoscopy | Case series | All EILO-positive (by design) n=83 glottic (84% female); age 14±2.6 years n=60 supraglottic (77% female); age 14±2.3 years
| Retrospective design Highly selected population Post-exercise laryngoscopy |
Marcinow et al. [104] | 2014 | n=46 Elite athletes and age- and sex-matched non-athletes, both with verified PVFMD
| Case–control | All PVFMD-positive (by design) Age 21 (18–69) years 70% female 39% had verified asthma
| Retrospective design Highly selected population Only glottic component considered |
Hanks et al. [105] | 2012 | n=148 Athletes referred to a tertiary asthma clinic for evaluation of exertional dyspnoea | Cross-sectional | 70% of tested (n=82) had VCD Median age 19 years 73% female 31% of VCD-positive subjects had verified EIB 6% had verified asthma
| Retrospective design Diagnosis by videolaryngostroboscopy |
Johansson et al. [3] | 2015 | n=125 (n=2309 screened) General population with exertional dyspnoea | Cross-sectional | 11% of cases and 4% of controls had EILO Mean (range) age 14.2 (13–15) years Estimated prevalence of EILO in the general population: 5.7% (equal for male and female) 44% of EILO-positive subjects had verified EIB | Well-designed Did not report details on glottic/supraglottic components |
Hilland et al. [58] | 2016 | n=20 (cases) Patients with a history of childhood laryngomalacia requiring hospital admission | Case–control | 70% EILO-positive Age 12.7±2.7 years 35% female 70% supraglottic 45% of EILO-positive subjects had anomalies at rest
| Highly selected population |
Walsted et al. [7] | 2016 | n=37 Patients with suspected asthma and exertional dyspnoea referred to a tertiary asthma clinic | Cross-sectional | 22% EILO-positive Median (IQR) age 22.5 (12) years 100% female 88% supraglottic 14% of EILO-positive had verified asthma Inspiratory flow in mannitol and methacholine tests were poor predictors of EILO | Selected population |