Statistical primer: sample size and power calculations—why, when and how?†

Hickey, Graeme L.; Grant, Stuart W; Dunning, Joel; Siepe, Matthias

doi:10.1093/ejcts/ezy169

Cited by 108 publications

(69 citation statements)

References 25 publications

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“…All analyses were evaluated with SPSS version 20.0 (SPSS 20.0, IBM, USA). A power analysis was conducted with PASS 19.0 to calculate the number of subjects needed in this study; PASS (https ://www.ncss.com/softw are/pass) is a professional software used to calculate sample size [42]. We found that the incidence of increased CIMT in patients with T2DM was 23.5% in a study conducted in a Chinese population [27].…”

Section: Discussionmentioning

confidence: 99%

Analysis of risk factors for carotid intima-media thickness in patients with type 2 diabetes mellitus in Western China assessed by logistic regression combined with a decision tree model

Zhou

Qiu

Yang

et al. 2020

Diabetol Metab Syndr

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Background: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with type 2 diabetes (T2DM). Carotid intima-media thickness (CIMT) is considered a preclinical stage of atherosclerosis. Therefore, it is necessary to identify the related risk factors for CIMT to facilitate the early prevention of CVD. Previous studies have shown that visceral fat area (VFA) is a risk factor for T2DM and CVD. However, few studies have focused on the effects of VFA on CIMT associated with T2DM. Moreover, considering that the body fat distribution shows regional and racial heterogeneity, the purpose of this study was to investigate the predictive value of VFA and other risk factors for CIMT associated with T2DM in Western China. Methods: In a cross-sectional study, a total of 1372 patients with T2DM were divided into the CIMT (−) group (n = 965) and the CIMT (+) group (n = 407) based on CIMT values. In addition to the univariate analyses, logistic regression analysis and a decision tree model were simultaneously performed to establish a correlation factor model for CIMT. Results: Univariate analyses showed that sex, smoking status, age, heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), height, weight, body mass index (BMI), waist circumference, hip circumference, waist-hip ratio, VFA, subcutaneous fat area, and the levels of 2-h C-peptide, serum creatinine, urea nitrogen and uric acid were significantly different between the two groups (all p < 0.05). Smoking, increased VFA, female sex and increased BMI were risk factors in the logistic regression analyses (OR = 5.759, OR = 1.364, OR = 2.239, OR = 1.186, respectively). In the decision tree model, smoking was the root node, followed by sex, waist circumference, VFA and chronic kidney disease (CKD) in order of importance. Conclusions: In addition to smoking, sex and BMI, VFA has a significant effect on CIMT associated with T2DM in the Chinese Han population in Western China. In addition, the decision tree model could help clinicians make more effective decisions, with its simplicity and intuitiveness, making it worth promoting in future medical research.

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Section: Discussionmentioning

confidence: 99%

Analysis of risk factors for carotid intima-media thickness in patients with type 2 diabetes mellitus in Western China assessed by logistic regression combined with a decision tree model

Zhou

Qiu

Yang

et al. 2020

Diabetol Metab Syndr

View full text Add to dashboard Cite

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“…The clinical characteristics, the proportion of severe patients and the mortality of patients with COVID-19 are different according to different individual publications. The main reason for the differences in different studies is that the sample size of each study is small with limited statistical power [30].…”

Section: Discussionmentioning

confidence: 99%

A Meta-analysis of Clinical Characteristics and Mortality COVID-19 Pneumonia

Jiang

Lou

et al. 2020

Preprint

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Objective To investigate the Corona Virus Disease 2019(COVID-19) clinical characteristics and mortality risk by pooling the open published data.Methods Studies relevant to COVID-19 published in Pubmed, China Wanfang database, ChinaXiv and medRxiv were systematic screened by using the text word of “COVID-19”, 2019-nCoV, “SARS-CoV-2”, “NCP”. The mortality and clinical characteristic of the COVID-19 cases such as male/female ratio, mechanical ventilation ratio and top clinical symptom rate of the COVID-19 cases were pooled.ResultsTen clinical studies relevant to COVID-19 were identified by electronic searching the related databases. The combined mortality was 0.03(95%CI: 0.01-0.04) for COVID-19 cases by random effect model. The pooled female ratio of the COVID-19 cases from 10 published data was 0.41(95%CI:0.37-0.46). The pooled invasive and non-invasive ventilation ratio were 0.03(95%CI:0.01-0.05) and 0.06(95%CI:0.02-0.09) respectively for patients with COVID-19 pneumonia. The pooled clinical symptom rate of fever, cough, headache and fatigue were 0.80(95%CI:0.60-1.01), 0.12(95%CI:0.08-0.17), 0.68(95%CI:0.57-0.73) and 0.51(95%CI:0.36-0.67) respectively under random effect model.Conclusion According to the present published data, male was more cline to susceptible to COVID-19 compared to female. The fever, cough and fatigue were the most common symptom of COVID-19 cases. About 10% of patients received invasive or noninvasive mechanical ventilation with the overall crude mortality of 3%.

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“…The sample size was calculated with a significance between treatment and placebo groups at P = .05 and a power of 80% using the result of body fat mass and percentage reported by Nosaka et al 24 The required number of subjects was determined using a power calculation according to published guidelines for human dietary intervention studies. 25,26 The Sinetrol-XPur and placebo tablets were provided by the investigators every 6 weeks, and compliance was assessed at every follow-up. Compliance was monitored through a trained researcher by calculating remnant tablet strips from the participants at the third and fourth visits.…”

Section: Methodsmentioning

confidence: 99%

Efficacy and Safety of Sinetrol-XPur on Weight and Body Fat Reduction in Overweight or Obese Adults: A 12-Week, Randomized, Double-Blind, Parallel, Placebo-Controlled Trial

Park

Sharma

Bae

et al. 2020

Journal of Medicinal Food

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This study investigated the effect of Sinetrol-XPur on weight and body fat reduction in overweight or obese Korean participants. Among 100 overweight or obese participants enrolled in a 12-week randomized, double-blinded, controlled study, 86 participants completed the trial. Participants took either two Sinetrol-XPur tablets (450 mg per tablet) or two placebo tablets once a day. Bodyweight, body fat percentage, body mass index (BMI), body fat mass, waist circumference, and various safety parameters were measured. After the 12-week intervention, a significant reduction was observed in the body fat mass (P = .030) by dual-energy X-ray absorptiometry (DEXA), body weight (P = .002), and BMI (P = .002) compared to the placebo. Body fat percentage (P = .007) by DEXA showed a significant reduction in the Sinetrol-XPur group, but no difference compared to the control group. Abdominal metabolic risks by computed tomography and blood biochemistry analysis were significantly decreased in the Sinetrol-XPur group, but there were no differences between the Sinetrol-XPur and placebo groups. Safety profiles were not different between the two groups. These results suggested that Sinetrol-XPur significantly reduced body weight, body fat mass, and BMI in obese Korean subjects, which confirms the antiobesity effect of Sinetrol-XPur in the Korean population.

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Statistical primer: sample size and power calculations—why, when and how?†

Cited by 108 publications

References 25 publications

Analysis of risk factors for carotid intima-media thickness in patients with type 2 diabetes mellitus in Western China assessed by logistic regression combined with a decision tree model

Analysis of risk factors for carotid intima-media thickness in patients with type 2 diabetes mellitus in Western China assessed by logistic regression combined with a decision tree model

A Meta-analysis of Clinical Characteristics and Mortality COVID-19 Pneumonia

Efficacy and Safety of Sinetrol-XPur on Weight and Body Fat Reduction in Overweight or Obese Adults: A 12-Week, Randomized, Double-Blind, Parallel, Placebo-Controlled Trial

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