Chetta Ngamjarus

A Comparison of Statistical Methods for Identifying Out-of-Date Systematic Reviews

Background Systematic reviews (SRs) can provide accurate and reliable evidence, typically about the effectiveness of health interventions. Evidence is dynamic, and if SRs are out-of-date this information may not be useful; it may even be harmful. This study aimed to compare five statistical methods to identify out-of-date SRs. Methods A retrospective cohort of SRs registered in the Cochrane Pregnancy and Childbirth Group (CPCG), published between 2008 and 2010, were considered for inclusion. For each eligible CPCG review, data were extracted and “3-years previous” meta-analyses were assessed for the need to update, given the data from the most recent 3 years. Each of the five statistical methods was used, with random effects analyses throughout the study. Results Eighty reviews were included in this study; most were in the area of induction of labour. The numbers of reviews identified as being out-of-date using the Ottawa, recursive cumulative meta-analysis (CMA), and Barrowman methods were 34, 7, and 7 respectively. No reviews were identified as being out-of-date using the simulation-based power method, or the CMA for sufficiency and stability method. The overall agreement among the three discriminating statistical methods was slight (Kappa = 0.14; 95% CI 0.05 to 0.23). The recursive cumulative meta-analysis, Ottawa, and Barrowman methods were practical according to the study criteria. Conclusion Our study shows that three practical statistical methods could be applied to examine the need to update SRs.

Supplementary techniques for pain control during root canal treatment of lower posterior teeth with irreversible pulpitis: A systematic review and meta‐analysis

The purpose of this systematic review and meta-analysis was to evaluate utilisation of supplementary techniques for pain control during root canal treatment of lower molars with irreversible pulpitis. The literature was searched using electronic databases up to year 2012. Seventeen studies with 1504 participants were included and each study compared experimental interventions with a standard treatment, i.e. the inferior alveolar nerve block. Changing the injection techniques or supplemental injection had no significant effect on pulp anaesthesia compared to the standard treatment (P = 1.00 or P = 0.14), whereas changing anaesthetic features and increasing anaesthetic volumes resulted in significantly higher rates of anaesthesia than those of the standard treatment (P = 0.03 and P = 0.007, respectively). Premedication with non-steroidal anti-inflammatory drugs (NSAIDs) also significantly increased the success rate of anaesthesia (P = 0.001). Taken together, increased anaesthetic volumes and premedication with NSAIDs provide predictable anaesthesia and more pain control during endodontic treatment of lower molars with irreversible pulpitis.