TY - JOUR A1 - Hackenbroich, Samantha A1 - Kranke, Peter A1 - Meybohm, Patrick A1 - Weibel, Stephanie T1 - Include or not to include conference abstracts in systematic reviews? Lessons learned from a large Cochrane network meta-analysis including 585 trials JF - Systematic Reviews N2 - Background Systematic reviews attempt to gather all available evidence. Controversy exists regarding effort and benefit of including study results presented at conferences only. We recently published a Cochrane network meta-analysis (NMA) including 585 randomized controlled trials comparing drugs for prevention of postoperative nausea and vomiting (PONV). Studies published as conference abstracts only were excluded. This study aimed to include all eligible studies published as abstracts only, assessing their added value regarding reporting quality and effect on the review’s interpretation. Methods Conference abstracts were searched in the review’s excluded studies and conference proceedings of anaesthesiologic societies. We assessed their reporting quality regarding review’s eligibility criteria, Cochrane ‘risk of bias’ assessment tool 1.0, and adherence to CONSORT (Consolidated Standards of Reporting Trials) for abstracts. Abstracts were included in sensitivity NMA, and impact on the NMA structure was investigated. Results We identified 90 abstracts. A total of 14% (13/90) were eligible. A total of 86% (77/90) are awaiting classification due to insufficient reporting of review’s eligibility criteria. In abstracts awaiting classification, sufficient information was missing on standardization of anaesthesia in 71% (55/77), age of participants in 56% (43/77), and outcome details in 46% (36/77). A total of 73% (66/90) of abstracts lacked sufficient information on 15/25 data extraction items. Reported study characteristics of abstracts were comparable to included studies of the review. A total of 62% (56/90) of abstract trials were assessed as overall high risk of bias due to poor reporting. Median adherence to CONSORT for abstracts was 24% (IQR, 18 to 29%). Six of the 13 eligible abstracts reported relevant outcome data in sufficient detail for NMA on seven outcomes of the Cochrane review. Inclusion of abstracts did not substantially change the network structure, network effect estimates, ranking of treatments, or the conclusion. Certainty of evidence for headache on palonosetron use was upgraded from very low to low. Conclusions Most conference abstracts on PONV were insufficiently reported regarding review’s narrow inclusion criteria and could not be included in NMA. The resource-intensive search and evaluation of abstracts did not substantially extent the full-text evidence base of the review, given the few adequately reported abstracts. Conferences should oblige authors to adhere to CONSORT for abstracts. KW - systemic reviews KW - conference abstracts KW - meta-analysis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299660 VL - 11 IS - 1 ER - TY - THES A1 - Hackenbroich, Samantha T1 - Effekt der Inklusion von Abstraktpublikationen in die Netzwerk-Metaanalyse zur Prävention von postoperativer Übelkeit und Erbrechen und Analyse der Berichterstattungsqualität T1 - Effect of inclusion of abstract publications in the network meta-analysis on prevention of postoperative nausea and vomiting and assessment of reporting quality N2 - Systematische Übersichtsarbeiten und Metaanalysen zielen darauf ab, die gesamte verfügbare Evidenz zu einer Fragestellung zu erfassen. Die aktuelle Cochrane Netzwerk-Metaanalyse (NMA) verglich Antiemetika zur Prävention von postoperativer Übelkeit und Erbrechen. Die vorliegende Untersuchung ergänzte den Studienpool retrospektiv um die ursprünglich exkludierten Kongressabstracts und analysierte deren Mehrwert hinsichtlich Berichterstattungsqualität und Auswirkung auf die NMA. Kongressabstracts wurden bezüglich Studiencharakteristika, Biasrisiko und Berichter-stattung analysiert. Die Auswirkung des Einschlusses von Abstracts wurde mittels Sensitivitäts-Netzwerk-Metaanalysen analysiert. Anhand CONSORT (Consolidated Standards of Reporting Trials) für Abstracts wurde ein Beispielabstract verfasst. Von 90 identifizierten Abstracts waren 14 % (13/90) inkludierbar und bei 86 % (77/90) ist die Klassifikation im Hinblick auf Ein- oder Ausschlussfähigkeit aufgrund insuffizienter Berichterstattung der engen Einschlusskriterien der NMA ausstehend. Dabei fehlten bei 71 % (55/77) der Abstracts Informationen zur Standardisierung der Anästhesie, bei 56 % (43/77) zum Alter der Teilnehmer und bei 46 % (36/77) zu den Endpunktdetails. In 73 % (66/90) der Abstracts fehlten suffiziente Informationen zu 15 von 25 Datenextraktions-merkmalen. Die berichteten Studiencharakteristika der Abstracts waren vergleichbar mit den inkludierten Studien der NMA. 62 % (56/90) der Abstractstudien hatten aufgrund mangelhafter Berichterstattung ein hohes Gesamt-Biasrisiko. Die Adhärenz zu CONSORT für Abstracts betrug im Median 24 % (IQR: 18 % - 29 %). Eine Verbesserung der Berichterstattung nach der Publikation von CONSORT für Abstracts war nicht zu beobachten. Nur sechs der inkludierbaren Abstracts berichteten relevante Endpunktdaten suffizient und konnten in Sensitivitäts-NMAs inkludiert werden. Deren Inklusion führte weder zu einer relevanten Änderung der Netzwerkstruktur oder Effektschätzungen noch des Rankings der Wirksamkeit der Antiemetika bzw. der klinischen Konklusion. Eine Empfehlung für zukünftige Abstracts mit Vorlage entsprechend der Kriterien der Fachgesellschaften sowie CONSORT für Abstracts konnte entwickelt werden. Die Mehrheit der identifizierten Abstracts waren insuffizient berichtet und konnten daher nicht eingeschlossen werden. Kongressorganisatoren sollten ihre Autoren zur Umsetzung von CONSORT für Abstracts verpflichten. Die ressourcenintensive Einbeziehung von Abstracts brachte keinen relevanten Evidenzgewinn. Somit kann die Inklusion von Kongressabstracts in systematische Übersichtsarbeiten mit engen Inklusionskriterien und solider Volltext-Evidenzbasis nicht empfohlen werden. N2 - Systematic reviews attempt to gather all available evidence. The current Cochrane network meta-analysis (NMA) compared antiemetics for prevention of postoperative nausea and vomiting. Studies published as conference abstracts only were excluded. This study retrospectively aimed to include studies published as conference abstracts only assessing their added value regarding reporting quality and effect on the review. Conference abstracts were analysed regarding study characteristics, risk of bias and reporting quality. Sensitivity network meta-analyses were conducted to assess the effect of the inclusion of the abstracts on the review. Using CONSORT (Consolidated Standards of Reporting Trials) an example abstracts was created. Of 90 abstracts identified, 14% (13/90) were eligible and 86% (77/90) are awaiting classification due to insufficient reporting of the NMA's narrow eligibility criteria. Among these, 71% (55/77) lacked information on standardisation of anaesthesia, 56% (43/77) lacked information on participant age, and 46% (36/77) lacked information on endpoint details. Sufficient information was missing on 15 of 25 data extraction items in 73% (66/90) of abstracts. The reported study characteristics of the abstracts were comparable to the included studies in the NMA. 62% (56/90) of abstract studies were assessed as overall high risk of bias due to poor reporting. Median adherence to CONSORT for abstracts was 24% (IQR: 18 to 29%). There was no improvement in reporting after publication of CONSORT for abstracts. Only six of the eligible abstracts reported relevant outcome data in sufficient detail to be included in sensitivity NMAs. Inclusion of abstracts did not substantially alter network structure, network effect estimates, nor the ranking of treatments or the conclusion. A recommendation for future abstracts according to criteria of societies in anaesthesiology and CONSORT for abstracts was developed. Most abstracts identified were insufficiently reported and therefore could not be included in NMA. Conferences should oblige their authors to adhere to CONSORT for abstracts. Resource-intensive inclusion of abstracts did not yield relevant evidence gains. Thus, inclusion of conference abstracts in systematic reviews with narrow inclusion criteria and solid full-text evidence base cannot be recommended. KW - Berichterstattung KW - Systematische Übersichtsarbeit KW - postoperative Übelkeit KW - Erbrechen Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-321669 ER -