ObjectiveTo assess the cosmetic outcomes and adverse events of MammoSite balloon brachytherapy for Accelerated Partial Breast Irradiation following breast-conserving surgery for patients with early stage breast cancer. MethodsWe searched PubMed, EMbase, Chinese Biomedical Database, Chinese Studies Online, China Journal Full-text Database up to March 2016, to collect clinical trials about MammoSite balloon brachytherapy following breast-conserving surgery for early stage breast cancer. And meta-analyses were performed by OpenMeta and Stata softwares. ResultsTwenty trials involving 3 796 patients were enrolled. The single arm meta-analysis results showed that:the cosmetic results were rated as excellent to good in 93% (95%CI 0.91 to 0.96), and the 5-year incidence of ipsilateral breast tumor recurrence (IBTR) was 3% (95%CI 0.020 to 0.040). ConclusionTo carry out the conclusion above, we still need controlled trials, especially randomized controlled trials (RCTs) to prompt further verification.
ObjectiveTo explore the parameter selection of different sample size estimation methods and the differences in estimation results in single-group target value clinical trials with rate as the outcome evaluation index. MethodsWe conducted a literature review to assess the method of target value selection for single-group target value clinical trials. Then, different values of target value (P0), clinical expected value (P1), and class II error level (β) were set through numerical simulation. Sample size results estimated using different sample size estimation methods were obtained using PASS software. The coefficient of variation, range/mean, analysis of variance and other methods were used to compare the differences between different methods. ResultsAnalysis of the data simulation results showed: when the expected value P1 was fixed, the sample size first decreased rapidly and then decreased slowly along with the increase or decrease of the targeted value P0 on both sides of the sample size limit value. When the difference between P0 and P1 was within 0.15, the ratio before and after correction could be controlled within 0.9. When the difference between P0 and P1 was more than 0.6, the ratio before and after correction approached 0.5. When P0+P1≈1, the ratio of different standard error choices (Sp0 or Sp1) to the estimated sample size was close to 1. When 0.65<P0+P1<1.35, the ratio of different standard error choices (Sp0 or Sp1) to the estimated sample size was about 3:1. When the confidence was 0.8, P0 and P1 were between 0.25 and 0.75 and between 0.20 and 0.80, respectively. We found little difference among the sample sizes estimated using these five methods (CV<0.10, range/mean<0.2). ConclusionThere are some differences among different sample size estimation methods, however, when P0 and P1 values are around 0.5, the differences between different methods are small, suggesting that appropriate methods should be selected for sample size estimation.
Objective To understand the feasibility of application of objective performance criteria single arm trial in clinical efficacy evaluation of traditional Chinese medicine, and put forward theoretical countermeasures for the difficulties in application, so as to provide references for promoting the application of objective performance criteria single arm trial in clinical efficacy evaluation of traditional Chinese medicine in the future. Methods Semi-structured qualitative interviews were conducted among clinical experts and methodologists who were involved in objective performance criteria single arm trials using purposive sampling combined with snowball sampling and a preset interview outline. To explore the application situations, influencing factors and difficulties in the application process of objective performance criteria single arm trial in the clinical efficacy evaluation of traditional Chinese medicine, and put forward theoretical countermeasures. Results A total of 12 respondents were interviewed, including 7 clinical experts and 5 methodologists. The interview content was summarized and formed into 216 codes. After category analysis, 5 categories were formed, including the applicable situations, advantages, limitations, difficulties in the application process and theoretical countermeasures. The respondents believed that objective performance criteria single arm trial could be used as an alternative plan when controlled trials could not be carried out, or as a preliminary exploration or evidence supplement. It had the advantages of reducing sample size, good patient compliance, saving resource input, and relatively rigorous design. However, its application was limited due to low awareness and unclear level of evidence. The application difficulties included the setting of objective performance criteria, sample size calculation, quality control and statistical analysis. It was suggested to form a standard to promote its application in the efficacy evaluation of traditional Chinese medicine. Conclusion The design of objective performance criteria single arm trial is consistent with the characteristics of clinical research of traditional Chinese medicine. However, because there is no control group, the validity of objective performance criteria single arm trial is challenged, which hinders its further application in the clinical efficacy evaluation of traditional Chinese medicine. By standardizing the selection of objective performance criteria, calculation of sample size, statistical analysis methods and research implementation steps, the strength of its demonstration and the recognition can be improved to a certain extent, but attention should be paid to avoid its misuse. In the future, the objective performance criteria single arm trial may be used as a basis to further explore the new direction of scientific research methods for clinical efficacy evaluation of traditional Chinese medicine.