A comparison of non-iterative and iterative estimators of heterogeneity variance for the standardized mortality ratio

This paper continues work presented in B\ua8ohning et al. (2002b, Annals of the Institute of Statistical Mathematics 54, 827\u2013839, henceforth BMSRB) where a class of non-iterative estimators of the variance of the heterogeneity distribution for the standardized mortality ratio was discussed. Here, these estimators are further investigated by means of a simulation study. In addition, iterative estimators including the Clayton\u2013Kaldor procedure as well as the pseudo-maximum-likelihood (PML) approach are added in the comparison. Among all candidates, the PML estimator often has the smallest mean square error, followed by the non-iterative estimator where the weights are proportional to the external expected counts. This confirms the theoretical result in BMSRB in which an asymptotic efficiency could be proved for this estimator (in the class of non-iterative estimators considered). Surprisingly, the Clayton\u2013Kaldor iterative estimator (often recommended and used by practitioners) performed poorly with respect to the MSE. Given the widespread use of these estimators in disease mapping, medical surveillance, meta-analysis and other areas of public health, the results of this study might be of considerable interest

Predictors of myocardial reperfusion in patients with ST-elevation myocardial infarction following thrombolytic treatment in rural community

© 2020, Walailak University. All rights reserved. This cross-sectional study aims to examine patient and hospital factors contributing to reperfusion following thrombolysis in patients with ST-segment elevation myocardial infarction (STEMI) in rural hospitals in Thailand. Access to reperfusion therapy for STEMI patients in rural areas is increasing in Thailand, yet clinical outcomes vary between settings and are inferior to recommended guidelines. Ten years after the introduction of thrombolytic treatment for rural patients undergoing STEMI, there is still a limited description of factors influencing the outcomes of thrombolytic treatment. Data were collected from 87 acute STEMI patients who had received thrombolytic treatment in 12 thrombolysis-capable hospitals located in rural areas. Demographic and clinical characteristics included patient response and treatment seeking behavior, witness response to the patient symptoms, waiting time for treatment, severity of illness, guideline adherence, and thrombolytic reperfusion. The results were: only 31 of 87 patients (35.63 %) received thrombolytic treatment within 30 min after arrival at the hospital. A total of 42 patients (48.28 %) had successful myocardial reperfusion following thrombolytic treatment. Logistic regression analysis revealed that guideline adherence (OR: 1.58; 95 % CI: 1.12-2.25), severity of illness (OR: 0.77; 95 % CI: 0.64-0.94), and patient response and treatment seeking behavior (OR: 1.47; 95 % CI: 1.01-2.04) were predictors of thrombolytic reperfusion. In rural areas, healthcare resources and transfer facilities are limited. Therefore, the improvement of patient awareness is needed. The clinical practice guidelines and consideration of pre-hospital factors should be promoted and the number of thrombolysis-capable hospitals should be increased