1.The application of sequential analysis for continuous post-market vaccine safety surveillance
Zixuan LU ; Musu LI ; Jiahe PAN ; Yiwen WU ; Huilin LI ; Er YU ; Hongmei WO ; Shaowen TANG ; Yang ZHAO ; Juncheng DAI ; Honggang YI
Chinese Journal of Epidemiology 2025;46(3):514-518
To explore the application of sequential analysis in post-market safety dynamic surveillance of vaccines. Under the dynamic monitoring data of vaccines post-market approval, this research introduces the fundamental principles of maximizing sequential probability ratio test (MaxSPRT) and Bayesian sequential analysis, employing R software. Through an example of dynamic safety monitoring data of vaccines post-market approval, we analyze using the MaxSPRT and Bayesian sequential analysis. The MaxSPRT identified a safety signal in week 4 ( P<0.05), while Bayesian sequential analysis indicated that the 95% highest density interval for the RR value at week 4 is 1.13-3.27, suggesting the first appearance of a safety signal at week 4. The MaxSPRT and Bayesian sequential analysis effectively leverage continuously accumulating dynamic monitoring data, thereby serving as a valuable method for post-market safety surveillance of vaccines.
2.Application of the Bayesian mixture model based on a principal stra-tum strategy in clinical trials
Yiwen WU ; Yue SUN ; Zixuan LU ; Jiahe PAN ; Er YU ; Hongmei WO ; Shaowen TANG ; Yang ZHAO ; Juncheng DAI ; Honggang YI
Chinese Journal of Clinical Pharmacology and Therapeutics 2025;30(7):942-949
AIM:To evaluate the application effec-tiveness of a Bayesian mixture model based on the principal stratum strategy for estimating the com-plier average causal effect(CACE)in clinical trials with non-compliance.METHODS:Using a non-infe-riority randomized controlled trial investigating a novel drug for primary type 2 diabetes mellitus(non-inferiority margin:-0.4)as a case study,the primary analysis applied a Bayesian mixture model under the monotonicity assumption to estimate CACE of between-group differences in glycated he-moglobin(HbA1c)changes within the compliant stratum,followed by non-inferiority testing.Sensi-tivity analyses included a Bayesian mixture model relaxing the monotonicity assumption and compar-ing results with per-protocol set(PPS)analysis.RE-SULTS:In the primary analysis,the posterior mean of CACE for HbA1c change in the compliant stratum was 0.081%,with a one-sided 97.5%credible inter-val lower bound of-0.124,exceeding the non-infe-riority margin(-0.4%),supporting the non-inferiori-ty efficacy of the novel drug in the compliant stra-tum(P(H1|Data)=1).Consistent findings were ob-served in PPS analyses(estimated effect:0.136%;one-sided 97.5%credible interval lower bound:-0.069%),further validating methodological robust-ness.CONCLUSION:In clinical trials with noncom-pliance as an intercurrent event,the Bayesian mix-ture model under the principal stratum strategy ef-fectively adjusts for compliance-related bias and yields conservative,robust estimates of causal ef-fects,supporting its value in efficacy evaluation un-der complex compliance scenarios.
3.The application of sequential analysis for continuous post-market vaccine safety surveillance
Zixuan LU ; Musu LI ; Jiahe PAN ; Yiwen WU ; Huilin LI ; Er YU ; Hongmei WO ; Shaowen TANG ; Yang ZHAO ; Juncheng DAI ; Honggang YI
Chinese Journal of Epidemiology 2025;46(3):514-518
To explore the application of sequential analysis in post-market safety dynamic surveillance of vaccines. Under the dynamic monitoring data of vaccines post-market approval, this research introduces the fundamental principles of maximizing sequential probability ratio test (MaxSPRT) and Bayesian sequential analysis, employing R software. Through an example of dynamic safety monitoring data of vaccines post-market approval, we analyze using the MaxSPRT and Bayesian sequential analysis. The MaxSPRT identified a safety signal in week 4 ( P<0.05), while Bayesian sequential analysis indicated that the 95% highest density interval for the RR value at week 4 is 1.13-3.27, suggesting the first appearance of a safety signal at week 4. The MaxSPRT and Bayesian sequential analysis effectively leverage continuously accumulating dynamic monitoring data, thereby serving as a valuable method for post-market safety surveillance of vaccines.
4.Application of the Bayesian mixture model based on a principal stra-tum strategy in clinical trials
Yiwen WU ; Yue SUN ; Zixuan LU ; Jiahe PAN ; Er YU ; Hongmei WO ; Shaowen TANG ; Yang ZHAO ; Juncheng DAI ; Honggang YI
Chinese Journal of Clinical Pharmacology and Therapeutics 2025;30(7):942-949
AIM:To evaluate the application effec-tiveness of a Bayesian mixture model based on the principal stratum strategy for estimating the com-plier average causal effect(CACE)in clinical trials with non-compliance.METHODS:Using a non-infe-riority randomized controlled trial investigating a novel drug for primary type 2 diabetes mellitus(non-inferiority margin:-0.4)as a case study,the primary analysis applied a Bayesian mixture model under the monotonicity assumption to estimate CACE of between-group differences in glycated he-moglobin(HbA1c)changes within the compliant stratum,followed by non-inferiority testing.Sensi-tivity analyses included a Bayesian mixture model relaxing the monotonicity assumption and compar-ing results with per-protocol set(PPS)analysis.RE-SULTS:In the primary analysis,the posterior mean of CACE for HbA1c change in the compliant stratum was 0.081%,with a one-sided 97.5%credible inter-val lower bound of-0.124,exceeding the non-infe-riority margin(-0.4%),supporting the non-inferiori-ty efficacy of the novel drug in the compliant stra-tum(P(H1|Data)=1).Consistent findings were ob-served in PPS analyses(estimated effect:0.136%;one-sided 97.5%credible interval lower bound:-0.069%),further validating methodological robust-ness.CONCLUSION:In clinical trials with noncom-pliance as an intercurrent event,the Bayesian mix-ture model under the principal stratum strategy ef-fectively adjusts for compliance-related bias and yields conservative,robust estimates of causal ef-fects,supporting its value in efficacy evaluation un-der complex compliance scenarios.
5.Measurement and calculation of X-ray small fields' data for Varian accelerator
Xuetao WANG ; Shaowen CHEN ; Zhenhui DAI ; Lin ZHU ; Xiaowei LIU
Chinese Journal of Radiation Oncology 2012;(6):557-559
Objective The beam data is compared with those obtained from Monte Carlo (MC)simulation and measurement to investigate their feasibility and reliability for X-ray small fields.MethodsThe beam data,including the total scatter factor (Scp),percentage depth dose (PDD) was acquired byneasurement and calculation with the field size ranging from 0.5 cm × 0.5 cm to 10 cm x 10 cm.The resultswere compared and analyzed.Results All the data is most consistent for the fields size of ≥3.5 cmx 3.5cm,but they are obvious different for the fields size of ≤ 3.0 cm × 3.0 cm.The measurements seem toreliable using the chambers of CC04 and CC13 for the fields size of ≥2.0 cm x 2.0 cm.Conclusions It isdemonstrated that the accurate measurements and calculations of Scp and PDD can be obtained for the fieldssize of ≥2.0 cm ×2.0 cm,but they needed morc rcscarchcs for thc smaller fields.
6.Management of the non-vital teeth with open apices using mineral trioxide aggregate
Journal of Practical Stomatology 1995;0(04):-
Objective:To describe the procedures for management of the non-vital teeth with open apices using mineral trioxide aggregate(MTA). Methods:Six non-vital teeth with open apices in 6 patients aged 10~20 years old were treated with MTA. After a rubber dam was applied, a large access was made for debridement of the canal. Calcium hydroxide paste was placed in the canal for 1 week for disinfection. After the calcium hydroxide was rinsed from the canal at the subsequent appointment, a mixture of MTA powder with sterile water was carried into the canal with an amalgam carrier. The mix was condensed to the apical extent using pluggers to create a 3-4 mm apical plug. To ensure proper setting of MTA, a moist cotton pellet was placed in the canal over the material and the tooth was temporized, The remainder of the canal was obturated with gutta-percha and sealer or bonded composite resin was placed in the access cavity at next visit. Results:The patients had no abnormal symptoms and signs after apical plug. Radiograph demonstrated all open apices healing 6 months after obturation. Conclusion:MTA is effective and convenient in the management of non-vital teeth with open apices.

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