Table 2 Level of evidence summary

Success 1st attempt

No data

No data

1+, 96-100% [23],[17],[14]

1+, 93-100% [19],[13]

Success Overall

3, 80-100% [20], [15]

3, 80-100% [20], [15]

1+, 96-100% [23],[17],[18],[14],[21],[16]

1+, 89-100% [22],[19],[90],[13]

% C&L 1 of glottis

3, 85- 100% [20], [15]

3, 89-100% [20], [15]

1+, Improvement, 90-95% [21],[18],[14]

1+, Improvement, 90-95% [19],[13]

Time to success

No data

No data

1+, No [16],[18],[23],[21]

1+, No [13],[22]

Success 1st attempt

3, 88% [27]

3, 88% [27]

1-, 88% [29]

3, 89% [30]

3, 88% [27]

Success Overall

3, 96% [27]

3, 96% [27]

1-, 82% [29]

1-, 86-98% [30],[25],[28],[24]

3, 96% [27]

% C&L 1 of glottis

No data

No data

1-, Improvement, 82% [29])

No data

Time to success

No data

No data

1-, No [29]

1-, No [28]

Success 1st attempt

No data

3, 89% [32]

1-, 86% [34]

1-, 92% [28]

3, 89% [32]

Success Overall

No data

3, 98% [32]

1-, 85-100% OA [34],[32],[33]

1-, 92% OA [28]

3, 98% [32]

% C&L 1 of glottis

No data

No data

No data

1-, Improvement, 92% [28]

Time to success

No data

No data

No data

1-, Yes [28]

Success 1st attempt

No data

No data

1-, 84-93% [48],[49],[36],[40],[17]

1-, 67-100% [44],[91],[39],[37],[45],[43],[46],[41]

Success Overall

3, 100% [38]

3, 95.8% [47]

1-, 90-100% [48],[18],[49],[42],[36],[40],[17]

1-, 93-100% [44],[91],[39],[37],[45],[43],[46],[41],[50]

% C&L 1 of glottis

3, 100% [38]

3, 95.8% [47]

1-, Improvement, 30-98% [41],[48],[42],[36],[49]

1-, Improvement, 28-93% [39],[46],[41],[50],[44],[91],[45],[37],[43]

Time to success

No data

No data

1-, No [36],[18],[48]

1-, No [43]

Success 1st attempt

No data

3, 90% [63]

1+ 16-93% [65],[64],[66],[54],[74],[59]

1-, 78-98% [73],[55],[56],[53],[58],[60],[44],[68],[35],[19], [71]

Success Overall

3, 94% [74]

3, 98-100% [62, 63]

1+, 89-100% [65],[64],[66],[54],[74],[72],[59],[61],[62]

1-, 71-100% [52],[55],[56],[53],[58],[60],[92],[67],[51],[44], [68],[35],[19],[71],[93]

% C&L 1 of glottis

No data

3, Improvement, 8% [62]

1+, Improvement, 33-88% [4],[72],[64],[61],[54],[59],[66]

1-, Improvement, 62-100% ([73],[67],[58],[56],[35],[53],[68],[94],[55],[60], [19],[44]

Time to success

No data

3, No [62]

1+, No [59],[72]

1-,No [71]

Success 1st attempt

No data

No data

No data

1-, 93-95% [75],[77]

Success Overall

3, Improvement, 83-95% [76],[79]

No data

No data

1-, 98-100% [75],[77]

% C&L 1 of glottis

3, Improvement, 77--87% [76],[79]

No data

No data

No data

Time to success

No data

No data

No data

1-, No [77]

Success 1st attempt

3, 94% [84])

3, 94% [84]

1+, 72-97% [59],[48],[95]^,[64]

1+, 87-96% [80],[83]^,[96],[85],[68],[35]

Success Overall

3, 99% [84]

3, 99% [84]

1+, 97-100% [59],[48],[95],[64],[81]

1+, 99-100% [80],[83],[96],[85],[68],[35]

% C&L 1 of glottis

3, Improvement, 96% [84]

3, Improvement, 96% [84]

1+, Improvement, 97-100% [59],[64],[48],[81],[66]

1+, Improvement, 97-99% [68],[35],[83]

Time to success

No data

No data

1+, No [81],[59],[95]

1+, Yes [85],[35]

Success 1st attempt

No data

No data

1+, 64% [65]

1-, 87-93% [87],[68]

Success Overall

No data

No data

1+, 98-100% [87],[65],[72],[88]

1-, 99-100% [87],[68],[89]

% C&L 1 of glottis

No data

No data

1+, Improvement, 31-45% [72],[88]

1-, Improvement, 43-100% [89],[86],[35],[87]

Time to success

No data

No data

1+, No [72]

1-, No [35]