Co-publishing Cochrane Library systematic reviews: journal editor and Cochrane Skin Group author experiences

Citation of updated and co-published Cochrane Methodology Reviews

BACKGROUND

To evaluate the number of citations for Cochrane Methodology Reviews after they have been updated or co-published in another journal, and the effect of co-publishing the review on the co-publishing journal's impact factor (IF).

METHODS

We identified all Cochrane Methodology Reviews published in the Cochrane Database of Systematic Reviews (CDSR) before 2018 and searched for co-published versions in the Web of Science Core Collection database up to 16 August 2022. The included reviews were in two cohorts: those that had been published and updated in CDSR and those that had been published in CDSR and co-published in another journal. The primary outcome measured the citation number to updated and original reviews in the first five years after publication of the updated review, and assessed the citation number of co-published and non-co-published reviews in the first five years after publication of the co-published version. The secondary outcome was the ratio of an adjusted IF and the actual IF of the co-publishing journal.

RESULTS

Eight updated and six original reviews were identified for the updated cohort of reviews, and four co-published reviews were included in the co-published cohort. The original reviews continued to be cited after the update was published but the median for the total number of citations was non-significantly higher for the updated reviews than for their original version[161 (Interquartile range (IQR) 85, 198) versus 113 (IQR 15, 433)]. The median number of total citations [362 (IQR 179, 840) versus 145 (IQR 75, 445)] and the median number of citations to the review in the first five years after co-publication combined and in each of those years was higher in the co-published group than in the non-co-published group. One of the three journals that co-published Reviews in the first year and two journals in the second year had a lower IF after co-publication.

CONCLUSIONS

Earlier versions of Cochrane Methodology Reviews continue to be cited after an update is published, which raises doubts about whether those citing are using the most recent evidence or are aware of the update. Co-publication facilitates broader application and dissemination of Cochrane methodology evidence.

Clinical Efficacy of Stem Cell Therapy for Diabetes Mellitus: A Meta-Analysis

BACKGROUND

Stem cell therapy is a promising therapeutic modality for advanced diabetes mellitus (DM). This study presents a meta-analysis of relevant clinical trials to determine the efficacy of stem cell therapy in DM. We aim to critically evaluate and synthesize clinical evidence on the safety and efficiency of different types of stem cell therapy for both T1DM and T2DM.

METHODS AND FINDINGS

We pooled participant-level data from twenty-two eligible clinical trials that satisfied our inclusion criteria, with a total of 524 patients. There were significant differences in the outcome based on the type and source of the infused cells. Out of all T1DM patients who received CD34+ hematopoietic stem cell (HSC) infusion, 58.9% became insulin independent for a mean period of 16 months, whereas the results were uniformly negative in patients who received umbilical cord blood (UCB). Infusion of umbilical cord mesenchymal stem cells (UC-MSCs) provided significantly beneficial outcome in T1DM, when compared to bone-marrow mesenchymal stem cells (BM-MSCs) (P<0.0001 and P = 0.1557). Administration of stem cell therapy early after DM diagnosis was more effective than intervention at later stages (relative risk = 2.0, P = 0.0008). Adverse effects were observed in only 21.72% of both T1DM and T2DM stem cell recipients with no reported mortality. Out of all poor responders, 79.5% were diagnosed with diabetic ketoacidosis.

CONCLUSIONS

Stem cell transplantation can represent a safe and effective treatment for selected patients with DM. In this cohort of trials, the best therapeutic outcome was achieved with CD34+ HSC therapy for T1DM, while the poorest outcome was observed with HUCB for T1DM. Diabetic ketoacidosis impedes therapeutic efficacy.

Cochrane systematic reviews and co-publication: dissemination of evidence on interventions for ophthalmic conditions

BACKGROUND

Systematic reviews of interventions provide a summary of the evidence available on intervention effectiveness and harm. Cochrane systematic reviews (CSRs) have been published electronically in the Cochrane Database of Systematic Reviews (CDSR) since 1994, and co-publication (publication of a Cochrane review in another journal) has been allowed since that time, as long as the co-publishing journal has agreed to the arrangement. Although standards for co-publication were established in 2008, the frequency of co-publication and adherence to the standards have remained largely unexamined. Our objective was to examine the frequency of co-publication of Cochrane Eyes and Vision Group (CEVG) reviews, adherence to the co-publication policy, the relative numbers of citations of the two modes of publishing, and differences in times cited in CSRs with and without a co-publication.

METHODS

We identified all CEVG reviews published by May 30, 2014 in The Cochrane Library. Using keywords from the title, author names, and "Cochrane Eyes and Vision Group", we searched Google Scholar, Web of Science, Scopus, and PubMed databases to identify possible co-publications. We also emailed contact authors of all identified CEVG reviews to ask them whether they had published their CSR elsewhere. We compared each co-publication to the corresponding CEVG review for adherence to the Cochrane Policy Manual (dated June 10, 2014). We recorded the number of times each CEVG review and each co-publication had been cited by others according to Google Scholar, Web of Science, and Scopus, as of June 11, 2014.

RESULTS

We identified 117 CEVG reviews;19 had been co-published in 22 articles. Adherence to Cochrane policy on co-publication was moderate, with all authors complying with at least one of four requirements we addressed. Co-publications were cited more often than the corresponding CEVG reviews; CEVG reviews with at least one co-publication were cited approximately twice as often as CEVG reviews without a co-publication. The number of citations varied considerably depending on whether the CEVG review had a co-publication or not.

CONCLUSIONS

The findings support encouraging co-publication while maintaining the primacy of the Cochrane systematic review. Support for co-publication may be tempered by other factors such as the possibility that CEVG reviews with a co-publication covered more clinically important and timely topics than those without a co-publication. Assuming that citations are a valid measure of dissemination effectiveness, the 15-year CEVG experience with co-publication of systematic reviews suggests that Cochrane authors should be encouraged to co-publish in traditional medical journals.