There is still room for improvement in the completeness of abstract reporting according to the PRISMA-A checklist: a cross-sectional study on systematic reviews in periodontology

Effect of PRISMA 2009 on reporting quality in systematic reviews and meta-analyses in high-impact dental medicine journals between 1993-2018

INTRODUCTION

The PRISMA guidelines were published in 2009 to address inadequate reporting of key methodological details in systematic reviews and meta-analyses (SRs/MAs). This study sought to assess the impact of PRISMA on the quality of reporting in the full text of dental medicine journals.

METHODS

This study assessed the impact of PRISMA (2009) on thirteen methodological details in SRs/MAs published in the highest-impact dental medicine journals between 1993-2009 (n = 211) and 2012-2018 (n = 618). The study further examined the rate of described use of PRISMA in the abstract or full text of included studies published post- PRISMA and the impact of described use of PRISMA on level of reporting. This study also examined potential effects of inclusion of PRISMA in Instructions for Authors, along with study team characteristics.

RESULTS

The number of items reported in SRs/MAs increased following the publication of PRISMA (pre-PRISMA: M = 7.83, SD = 3.267; post-PRISMA: M = 10.55, SD = 1.4). Post-PRISMA, authors rarely mention PRISMA in abstracts (8.9%) and describe the use of PRISMA in the full text in 59.87% of SRs/MAs. The described use of PRISMA within the full text indicates that its intent (guidance for reporting) is not well understood, with over a third of SRs/MAs (35.6%) describing PRISMA as guiding the conduct of the review. However, any described use of PRISMA was associated with improved reporting. Among author team characteristics examined, only author team size had a positive relationship with improved reporting.

CONCLUSION

Following the 2009 publication of PRISMA, the level of reporting of key methodological details improved for systematic reviews/meta-analyses published in the highest-impact dental medicine journals. The positive relationship between reference to PRISMA in the full text and level of reporting provides further evidence of the impact of PRISMA on improving transparent reporting in dental medicine SRs/MAs.

Cochrane review abstracts are getting longer, but this has no large impact on the reporting quality

OBJECTIVE

To evaluate the reporting of abstracts of Cochrane Reviews according to PRISMA-A and to investigate a possible association with the abstract´s length.

METHODS

This is a retrospective, observational study based on all Cochrane Reviews indexed in Medline (via PubMed) until November 18, 2022. In the second part, a random sample of 440 abstracts was drawn, in which PRISMA-A adherence was assessed by two independent reviewers. Analyses were stratified by the year of publication and the number of words.

RESULTS

Overall, the median number of words of the 15,188 included abstracts was 469 (IQR 389-686 words), steadily increasing from 353 words in 2000 to 838 words in 2022, with less than one percent of the abstracts in 2022 having ≤ 300 words (in 2000: 30.7%). Analyses on PRISMA-A adherence in the random sample showed a mean score of 6.1 out of 12 fully reported items. Stratified by year, PRISMA-A adherence increased, with higher word counts in 2000-2010 and 2011-2015, while there was no difference in PRISMA-A adherence by abstract length in 2016-2022.

CONCLUSION

Over the years, abstracts of Cochrane Reviews have become longer, running up to 1000 words. This conflicts with the Cochrane Handbook, which recommends a maximum length of 400 until it was aligned with MECIR in 2019, which has recommended a length of <700 words since 2012 but allows up to 1000 words. It is debatable whether such long abstracts meet the key goals of abstracts of being informative, accurate, appealing, and concise.

Reporting according to the preferred reporting items for systematic reviews and meta-analyses for abstracts (PRISMA-A) depends on abstract length

OBJECTIVE

To evaluate reporting of abstracts of systematic reviews according to the preferred reporting items for systematic reviews and meta-analyses for abstracts (PRISMA-A) 2013 checklist.

STUDY DESIGN AND SETTING

A random sample of 534 systematic reviews on effectiveness indexed in PubMed between 2000 and 2019 was assessed. Adherence of abstracts to PRISMA-A was analysed using descriptive statistics. Results were stratified by number of words, structure, and year of publication.

RESULT

The mean score of fully reported PRISMA-A items was 5.4 of 12, with adherence varying widely between items (0% to 98.8%). Cochrane reviews received higher mean total scores than non-Cochrane reviews (6.3 vs. 5.2). Adherence to PRISMA-A increased linearly with increasing word count. In non-Cochrane reviews, authors of structured abstracts more often adhered to PRISMA-A than those of unstructured abstracts. No improvements in reporting of abstracts were found after the implementation of PRISMA-A in 2013.

CONCLUSION

Adherence to PRISMA-A shows great potential for improvement. Therefore, authors, editors, and reviewers should be made aware of PRISMA-A by referring to it in the journal submission guidelines. As adherence to PRISMA-A increases with the number of words, journals should consider to increase the word limit to 250-300 words.