ObjectivesTo explore the statistical performance of different methods for meta-analysis of single rates with zero events so as to provide evidence for selecting meta-analysis methods in evidence-based research.MethodsThrough Monte-Carlo simulations, we evaluated the performance of various transformation and correction methods for meta-analysis of single rates with zero events, considering the point estimate bias, confidence interval coverage and width.ResultsWhen the overall event rate was above 30%, all methods showed good statistical performance. As the event rate dropped, log, logit, and arcsine transformations could still maintain good performance. However, when the event rate was less than 5%, only Freeman-Tukey transformation showed excellent performance.ConclusionsThe meta-analysis of single rate based on Freeman-Tukey transformation is robust, and should be recommended as the preferable choice of meta-analysis of single rate with zero events.
ObjectiveTo analyze the current status of the application of randomization methods in randomized controlled trials (RCTs) which have been published in New England Journal of Medicine (NEJM).MethodsRCTs published by NEJM in 2018 were searched and collected. The characteristics of clinical trial design elements and the application status of randomization methods were comprehensively analyzed to distinguish blind trial and non-blind trial, and characteristics of application of randomization methods and selection of allocation concealment mechanisms of non-blind trials were summarized.ResultsA total of 151 RCTs were published in NEJM in 2018, in which blinded trials and non-blinded trials accounted for 75 (49.67%) and 76 (50.33%), respectively. 34 (22.52%) RCTs did not report specific randomization methods, and the remaining 117 (77.48%) reported. Among the latter, stratified block randomization accounted for the main body (72.65%), followed by block randomization (11.11%), minimization method (9.40%), simple randomization method (4.27%) and the others. There was no significant difference in the proportion of reporting or using randomization methods between blind and non-blind trials (P>0.05). In 76 non-blind trials, 38 (50.00%) clearly reported the concealment method of random allocation, among which 37 used the central randomization (97.37%) and 1 used envelope method (2.63%).ConclusionsThe current RCTs published in NEJM still have problems in the selection of randomization methods to be optimized and the transparency of randomization reporting to be improved.
Objective To investigate the current situation of self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes mellitus (T2DM) in Sichuan province, and to analyze the influencing factors of SMBG, so as to provide evidence for improving the level of SMBG. Methods By the convenience sampling method, 410 patients with T2DM for more than 1 year were selected from 17 hospitals and community health service centers in 7 cities across Sichuan province, and their SMBG was investigated with a questionnaire. Results Among 410 eligible patients, the average frequency of SMBG was 7.3 times per month. There were 268 patients (65.4%) performed SMBG less than 4 times per month, 94 (22.9%) performed 4-15 times per month, 29 (7.1%) performed 6-29 times per month, and 19 (4.6%) performed over 30 times per month. Just 234 patients (57.1%) monitored the HbA1c in the past 6 months. FPG, 2-hour PPG and HbA1c were negatively correlated with the frequency of SMBG. The influencing factors of SMBG were insulin treatment and education. Conlusion The SMBG status in D2TM patients is relatively poor in Sichuan province, and the compliance of SMBG is expected to be improved by enhancing diabetic education.