Comparison of 7 methods for sample size determination based on confidence interval estimation for a single proportion / 南方医科大学学报

OBJECTIVE@#To compare different methods for calculating sample size based on confidence interval estimation for a single proportion with different event incidences and precisions.@*METHODS@#We compared 7 methods, namely Wald, AgrestiCoull add z2, Agresti-Coull add 4, Wilson Score, Clopper-Pearson, Mid-p, and Jefferys, for confidence interval estimation for a single proportion. The sample size was calculated using the search method with different parameter settings (proportion of specified events and half width of the confidence interval [ω=0.05, 0.1]). With Monte Carlo simulation, the estimated sample size was used to simulate and compare the width of the confidence interval, the coverage of the confidence interval and the ratio of the noncoverage probability.@*RESULTS@#For a high accuracy requirement (ω =0.05), the Mid-p method and Clopper Pearson method performed better when the incidence of events was low (P < 0.15). In other settings, the performance of the 7 methods did not differ significantly except for a poor symmetry of the Wald method. In the setting of ω=0.1 with a very low p (0.01-0.05), failure of iteration occurred with nearly all the methods except for the Clopper-Pearson method.@*CONCLUSION@#Different sample size determination methods based on confidence interval estimation should be selected for single proportions with different parameter settings.

The Awareness,Treatment and Control of Hypertension and Its Determinants in the Elderly Hypertensive Patients of Dean Nationality:A Multilevel Model Analysis / 昆明医科大学学报

Objective To determine the awareness, treatment and control of hypertension and its determinants in the elderly hypertensive patients of Dean nationality so as to explore the associated determinants. Methods This was a cross-sectional, population-based survey. A total of 939 persons aged 60 years and older sampled by stratified sampling method from the elderly population of Dean nationality were examined from July to September 2016. Meanwhile, the data of medical history and examination were collected. Results There were 353 elderly patients with hypertension in the 939 subjects. The awareness, treatment and control of hypertension in the elderly hypertensive patients (EHP), which was 47.3％, 36.5％and 22.1％respectively, were higher than the results of previous national study and had the upward trends with the increasing age (<0.05) . In comparison with the reference group, EHP living in middle economic level area had the higher awareness, treatment and control of hypertension (<0.05) . The results of covariate-adjusted multilevel logistic regression model indicated that there was a cross-level interaction effect between middle economic level area and dyslipidemia on the awareness and treatment of hypertension respectively, and a cross-level interaction effect between middle economic level area and low fat diet on the control of hypertension ( <0.05) . The individual level covariates, age (OR=1.3412, 1.3144, 95％ CI 1.0217-1.7609, 1.0030-1.7225) and diabetes ( OR=2.6735, 2.3078, 95％ CI 1.0721-6.6672, 1.0240-5.2007), had the positive association with the awareness and treatment of hypertension;age (OR=1.4740, 95％CI 1.0034-2.1654), non-drinking (OR=3.2056, 95％CI 1.5554-6.6066) and low salt diet (OR=3.6969, 95％CI 1.7996-7.5946) had the positive association with the control of hypertension. Conclusion The awareness, treatment and control of hypertension in the EHP of Dean nationality were higher than those of the national level, and the dominant factors were economic level, age, dyslipidemia, diabetes, non-drinking, low fat diet and low salt diet, etc.

Primary Plasma Cell Leukaemia

Plasma cell leukaemia (PCL) is a rare form of malignant plasma cell dyscrasia. It can occur as a primary form without prior evidence of multiple myeloma or as a secondary form which is a terminal event in multiple myeloma. It is characterised by a proliferation of plasma cells in blood and the bone marrow. The outcome of plasma cell leukemia is poor with conventional therapy. Here we illustrate a case of primary plasma cell leukemia complicated by para plegia. The patient initially responded to combination chemotherapy but succumbed to the disease two months after presentation