The sample size formula can be found in Fleiss et al.16 For paired cohort studies or case-cohort designs, the formulae can be found in Kasiulevičius et al17 and Cai and Zeng.9 When the outcome of interest in a cohort study is continuous (although it is less common), we would like...
We derive an explicit form for power/sample size calculation based on these two tests. A number of simulation studies have been used to illustrate the efficiency of the tests for the case-cohort design. An example is provided on how to use the formula. 展开 关键词:...
The sample size calculation formula for cohort was used based on the prevalence of malaria in the non-exposed group, which was estimated at 28% according to the study of Nyamu [16]. The prevalence of malaria in the exposed group estimated at 6.1% according to the DHIS2 [11]. Beta (10...
In this large study population, we calculated the average number of days undervaccinated (ADU) for each child across 8 vaccines during the first 24 months of life (Table 1). This calculation was based on a metric developed by Luman et al11 that measures the difference between when the vacc...
Using the formula p−=(p0+p1)/2, q−=1−p−, q1=1−p1, with a two-sided test level of α = 0.05 and β = 0.10, the sample size calculation formula for cohort studies (1) was applied. Assuming a 1:1 ratio between the exposed and control groups, 181 ...
(often to multiple exposures) is measured and the cohort is closely examined for the development of disease. As new cases of disease are identified in this study, calculation of incidence rates is possible. Associations between initial exposure and subsequent disease are measured usingrelative risk....
Sample size estimation We determined the sample size for our cohort study using OpenEpi software and the following cohort study sample size formula: (https://www.openepi.com/SampleSize/SSCohort.htm). The sample size was determined in line with the study’s primary objective—to identify the inc...
Sample size calculation The required baseline sample size was calculated to address the most sensitive objective (Aim 2) of this four-year study using standard methods [10]. Sample size was calculated to detect a rate ratio of 0.2 between slopes (considered a small effect size [10]) for expl...
Fig. 1 ARTiCO study sample selection. The diagram shows the sample selection in ARTiCO study from the reference population. SAVR: surgical aortic valve replacement; TAVI: transcathether aortic valve implantation. Full size image The sample size calculation will be based on the main study variable,...
Calculation of TyG index TyG index was calculated using the formula: TyG = Ln [fasting triglycerides (mg/dL) ×fasting glucose (mg/dL)/2]. Herein, we extracted the information of baseline fasting triglycerides and fasting glucose of the participants from the CHNS database to calculate the...