Table 3.

Univariable and multivariable negative binomial regression results

	Univariable			Multivariable
Journal	IRR	P value	95% CI	IRR	P value	95% CI
AO	1.26	0.36	0.76, 2.09	Reference
AJODO	1.15	0.56	0.72, 1.85	1.10	0.46	0.85, 1.43
OCR	1.10	0.76	0.58, 2.11	1.10	0.65	0.73, 1.67
EJO	1.86	0.02	1.12, 3.10	1.18	0.25	0.89, 1.58
PIOR	1.65	0.09	0.93, 2.91	1.17	0.35	0.84, 1.64
KJO	Reference			1.05	0.82	0.72, 1.53
Study type	IRR	P value	95% CI
RCT	0.73	0.26	0.42, 1.27
Prospective observational	0.79	0.31	0.51, 1.24
Retrospective observational	0.62	0.05	0.38, 1.00
Narrative or systematic review, meta-analysis	0.83	0.52	0.48, 1.45
Survey	0.61	0.27	0.25, 1.49
Case report	Reference
Topic	IRR	P value	95% CI
OHRQOL/esthetics/practice management/socio-demographics	1.79	0.20	0.74, 4.32
Biomaterials	1.15	0.36	0.60, 3.96
Diagnosis	1.67	0.25	0.70, 3.95
Treatment	1.77	0.19	0.76, 4.14
Growth	2.09	0.10	0.86, 5.07
New technologies	1.27	0.61	0.50, 3.20
Periodontics/caries prevention	1.53	0.42	0.55, 4.25
Side effects	1.23	0.68	0.46, 3.29
Other	Reference
Number of authors	IRR	P value	95% CI
1–3	1.17	0.34	0.85, 1.61
4–5	1.09	0.56	0.82, 1.45
> 5	Reference
Rank	IRR	P value	95% CI
First	1.06	0.59	0.86, 1.32
Last	Reference
Origin	IRR	P value	95% CI	IRR	P value	95% CI
Asia	Reference			Reference
Europe	1.63	0.00	1.28, 2.08	1.62	< 0.001	1.25, 2.11
North America	1.34	0.06	0.99, 1.82	1.34	0.06	0.99, 1.82
South America	1.06	0.75	0.74, 1.53	1.15	0.46	0.79, 1.67
Other/combination	1.41	0.02	1.05, 1.88	1.41	0.03	1.04, 1.90
Gender	IRR	P value	95% CI	IRR	P value	95% CI
Female	Reference			Reference
Male	1.31	0.01	1.06, 1.62	1.36	< 0.01	1.10, 1.68

IRR incidence rate ratio