Table 5 Outcome 3: types and categories of spin in abstracts of systematic reviews of orthodontic interventions

Misleading reporting

Category: Not reporting in the abstract on the results of adverse effects found in the review.

n = 2

n = 3

n = 2

n = 5

n = 0

n = 1

n = 11

Prevalence: 32.4% (11/34)

n = 13

Prevalence: 32.5% (13/40)

Misleading reporting

Category: Selective reporting in the abstract on the results of adverse effects found in the review

n = 4

n = 6

n = 4

n = 2

n = 2

n = 5

n = 19

Prevalence: 55.9% (19/34)

n = 23

Prevalence: 57.5% (23/40)

Misleading interpretation

Category:

Claiming in the abstract that the intervention is safe (has no or minimal adverse effects), despite concerning results on adverse effects found in the review

n = 1

n = 1

n = 1

n = 3

Prevalence: 8.8% (3/34)

n = 3

Prevalence: 7.5% (3/40)

Misleading (inappropriate) extrapolation

Category:

Results are extrapolated in the abstract to another population, intervention, outcome or setting than were assessed in the review despite evidence on adverse effects on a different population, intervention, outcome or setting.

n = 1

n = 1

Prevalence: 2.9% (1/34)

n = 1

Prevalence: 2.5% (1/40)