A comparison of quality of abstracts of systematic reviews including meta-analysis of randomized controlled trials in high-impact general medicine journals before and after the publication of PRISMA extension for abstracts: a systematic review and meta-analysis

Table 5 Factors associated with a better reporting of items of PRISMA for abstracts published in 2014

	Overall reporting quality		Methods reporting quality		Results reporting quality
	Adjusted incidence rate ratios (95 % confidence interval)^a	p	Adjusted incidence rate ratios (95 % confidence interval)^a	p	Adjusted incidence rate ratios (95 % confidence interval)^a	p
Abstract word count
<300 (ref)	1		1
≥300	0.83 (0.74; 0.92)	<0.001	0.70 (0.58; 0.86)	<0.001	1.02 (0.78; 1.33)	0.878
Abstract format
IMRAD (ref)	1
8-headings	1.26 (1.02; 1.56)	0.036	1.40 (0.94; 2.10)	0.099	1.41 (0.91; 2.20)	0.126
Publication on behalf of a group
No (ref)
Yes	1.01 (0.88; 1.15)	0.911	0.85 (0.52; 1.38)	0.497	0.99 (0.62; 1.58)	0.965
Number of authors
≤6 (ref)	1
>6	1.02 (0.91; 1.14)	0.761	0.89 (0.73; 1.08)	0.242	1.05 (0.78; 1.41)	0.743

Ref reference for mean difference calculation, PRISMA preferred reporting items for systematic review and meta-analysis, IMRAD introduction, methods, results, and discussion
^aGeneralized estimation equations with journal as grouping variable. PRISMA endorser variable was excluded from model because it was redundant

ISSN: 2046-4053