The importance of full text screening when judging eligibility criteria in a systematic review
a systematic survey
DOI:
https://doi.org/10.35699/2178-1990.2022.37521Keywords:
Review, Publication bias, Observational studies as topic, Dental cariesAbstract
Aim: To evaluate if statistically significant results are more likely to be reported in title/abstracts compared to non-significant outcomes.
Methods: In this methodological survey, we reanalyzed 59 observational studies from a previous systematic review. The PECO question was: Patient (P): children with primary teeth; Exposure (E): low birth weight and/or preterm; Comparison (C): normal birth weight and/or full-term; Outcome (O): dental caries. We analyzed the presence of key terms in the titles and abstracts, such as gestational age, preterm, full-term, birth weight, low/normal birth weight. Full texts were analyzed for “positive outcomes” (statistically significant association, p < 0.05 or 95% CI not crossing the null effect line) related to the association between the outcome and the exposure; and “negative outcomes” (when the outcome had statistically similar occurrence between the exposure and the comparison group). The odds ratio (OR) was calculated between the presence of key terms in titles/abstracts and the type of outcome (positive or negative).
Results: Of 59 studies, 66% cited the key terms in titles/abstracts, and 75% reported negative outcomes. Studies with positive outcomes were more likely to report key terms in the titles/abstracts compared to studies with negative outcomes (OR: 4.5; 95% CI: 0.9-22.4; Chi-square test: p = 0.06). Studies with statistically significant outcomes, favoring the exposure or the comparison, were more likely to report these data in the titles/abstracts.
Conclusion: When conducting a systematic review, the final decision related to the inclusion of a study must be based on a full-text level.
References
Kirkham JJ, Dwan KM, Altman DG, Gamble C, Dodd S, Smyth R, et al. The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews. BMJ. 2010;340:c365.
Lefebvre C, Glanville J, Briscoe S, Littlewood A, Marshall C, Metzendorf M, et al. Chapter 4: Searching for and selecting studies. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, et al. (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.1 (updated September 2020). Cochrane, 2020. Available from: www.training.cochrane.org/handbook.
Occhi-Alexandre IGP, Cruz PV, Bendo CB, Paiva SM, Pordeus IA, Martins CC. Prevalence of dental caries in preschool children born preterm and/or with low birth weight: a systematic review with meta-analysis of prevalence data. Int J Paediatr Dent. 2020;30:265-75.
Page MJ, McKenzie JE, Kirkham J, Dwan K, Kramer S, Green S, et al. Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions. Cochrane Database Syst Rev. 2014;10:MR000035.
Twetman S, Boustedt K, Roswall J, Dahlgren J. Systematic review suggests a relationship between moderate to late preterm birth and early childhood caries. Acta Paediatr. 2020;109(12):2472-8.
