Systematic reviews and meta-analysis demystified

Systematic reviews and meta-analysis both form essential research in today's scientific world with plethora of primary research in every filed. A systematic review is an overview of primary studies which contains an explicit statement of objectives, materials, and methods and is conducted according to the explicit and reproducible methodology. When systematic reviews provide a quantitative (statistical) estimate of net benefit aggregated over all the included studies, it is termed meta-analysis. In this review important individual components of systematic review and meta-analysis have been discussed for the benefit of our readers.     

Evaluation of cardiac signals using discrete wavelet transform with MATLAB graphical user interface

Aim

To process the electrocardiogram (ECG) signals using MATLAB-based graphical user interface (GUI) and to classify the signals based on heart rate.

Method

The subject condition was identified using R-peak detection based on discrete wavelet transform followed by a Bayes classifier that classifies the ECG signals. The GUI was designed to display the ECG signal plot.

Results

Obtained from MIT database 18 patients had normal heart rate and 9 patients had abnormal heart rate; 14.81% of the patients suffered from tachycardia and 18.52% of the patients have bradycardia.

Conclusion

The proposed GUI display was found useful to analyze the digitized ECG signal by a non-technical user and may help in diagnostics. Further improvement can be done by employing field programmable gate array for the real time processing of cardiac signals.     

ISO 13528稳健统计在常规化学室间质量评价葡萄糖结果分析中的应用

目的用ISO 13528稳健统计、z比分数和Youden图分析统一质控品常规化学室间质量评价质量改进计划中葡萄糖的结果。方法将实验室按照方法进行分组,计算各实验室与本组稳健平均值的百分差值,并以基于生物学变异的适当总误差质量规范计算其合格率。根据公式z=(x-X)/σ计算各实验室的z比分数,分析其分布。以两个批号样品的z比分数为横、纵坐标,绘制Youden图。结果本研究中回报葡萄糖结果的实验室共4 572家,两个批号样品的稳健平均值分别为6.31mmol/L和15.71 mmol/L,稳健标准差为0.23 mmol/L和0.5 mmol/L。按照使用的方法分组计算合格率,己糖激酶法较高,两个批号合格率均为93.6%,葡萄糖氧化酶法较低,为90.2%和90.7%。根据公式计算z比分数,两个批号|z|≤2的比例为91.6%和89.5%。在Youden图中有7.8%的实验室结果位于99%置信椭圆以外,且含有明显系统误差的实验室数多于随机误差实验室数。结论 ISO 13528稳健统计可用于室间质量评价结果分析,参加本研究的实验室葡萄糖项目的检测性能整体较佳。     

应用心电散点图鉴别心房颤动伴宽QRS波群的性质

患者女,75岁,有冠心病、房颤,24h动态心电图检测可见较宽大畸形的QRS波群间歇出现,时限120ms,其后无类代偿间歇,RR间期不等,考虑为间歇性室内阻滞,不排除室性自主心律。经心电散点图分析,该患者部分散点分布在动态房室结功能不应期(AVNFRP)界限与X轴之间,且B线斜率趋近于零,诊断为心房颤动伴室性自主心律。     

Lorenz散点图在慢性心力衰竭患者心率变异性分析中的应用研究

目的 探讨洛伦兹(Lorenz)散点图在慢性心力衰竭患者图心率变异性(HRV)分析中的应用.方法 回顾性分析2017年9月至2020年9月安庆市立医院收治的34例心力衰竭患者的动态心电图检查资料,作为心衰组;选取同期行动态心电图检查的30例非心力衰竭患者作为对照组.比较2组HRV指标,包括时域频域指标:24 h内相邻窦...