Power and Sample Size Calculations for Studies Involving Linear Regression

Dupont, William D.; Plummer, W. Dale

doi:10.1016/s0197-2456(98)00037-3

Cited by 911 publications

(628 citation statements)

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“…P values were calculated using two-sided chi-square test. The power (a = 0.05) was calculated using the power and sample size calculation software PS version 2.1.31 (http://www.mc.vanderbilt.edu/prev med/ps/index.htm) [39]. SNPs linked with all the 10 SNPs (Table 1) with r 2 C 0.8 and block definition were identified using HaploView version 3.32 (http://www.broad.mit.edu/ mpg/haploview).…”

Section: Discussionmentioning

confidence: 99%

A genetic variant in the pre-miR-27a oncogene is associated with a reduced familial breast cancer risk

Yang

Schlehe

Hemminki

et al. 2009

Breast Cancer Res Treat

113

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International audienceMicroRNAs (miRNAs) regulate pathways involved in cell differentiation, proliferation, development, and apoptosis by degradation of target mRNAs and/or repression of their translation. Although the single nucleotide polymorphisms (SNPs) in miRNAs target sites have been studied, the effects of SNPs in miRNAs are largely unknown. In our study, we first systematically sequenced miRNA genes reported to be involved in breast cancer to identify/verify SNPs. We analyzed four SNPs, one located in the pre-miRNA and the other three located in miRNA flanking regions, for a putative association with breast cancer risk. The SNP rs895819, located in the terminal loop of pre-miRNA-27a, showed a protective effect. In a large familial breast cancer study cohort, the rare [G] allele of rs895819 was found to be less frequent in the cases than in the controls, indicating a reduced familial breast cancer risk ([G] vs. [A]: OR = 0.88, 95% CI 0.78-0.99, = 0.0287). Furthermore, age stratification revealed that the protective effect was mainly observed in the age group < 50 years of age ([G] vs. [A]: OR = 0.83, 95% CI 0.70-0.98, = 0.0314), whereas no significant effect was observed in the age group ≥ 50 years of age, indicating a possible hormone-related effect. It has been shown that artificial mutations in the terminal loop of miR-27a can block the maturation process of the miRNA. We hypothesize that the G-variant of rs895819 might impair the maturation of the oncogenic miR-27a and thus, is associated with familial breast cancer risk

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Section: Discussionmentioning

confidence: 99%

A genetic variant in the pre-miR-27a oncogene is associated with a reduced familial breast cancer risk

Yang

Schlehe

Hemminki

et al. 2009

Breast Cancer Res Treat

113

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“…All statistical procedures were performed using SPSS® statistical package (SPSS Inc., Chicago, IL, USA), version 13.0 for Windows ® except for sample size calculation which was performed using PS Power and Sample Size Calculations Program ® , version 2.1.31 (Copyright © 1997 by WD Dupont and WD Plummer). 10 Results are presented as mean ± SD, unless otherwise indicated, and statistical significance was defined as P < 0.05.…”

Section: Discussionmentioning

confidence: 99%

Intravenous acetaminophenvs oral ibuprofen in combination with morphine PCIA after Cesarean delivery

Alhashemi

Alotaibi

Mashaat

et al. 2006

Can J Anesth/J Can Anesth

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Purpose:To compare the effects of iv acetaminophen with those of oral ibuprofen with respect to postoperative pain control and morphine requirements in patients receiving morphine patient-controlled iv analgesia (PCIA) after Cesarean delivery.Methods: Forty-five term patients scheduled for Cesarean delivery were randomized to receive acetaminophen 1 g iv every six hours plus oral placebo (group A) or ibuprofen 400 mg po every six hours plus iv placebo (group I); the first dose of study drug was given 30 min preoperatively. Postoperatively, all patients received PCIA for 48 hr using morphine bolus dose 2 mg iv, lockout interval ten minutes, and no basal infusion. Visual analogue scale (VAS; 0 to 10) at rest and morphine requirements were recorded every hour for four hours then every four hours for a total of 48 hr postoperatively. Patient satisfaction was recorded on a ten-point scale (from 1 to 10) 48 hr postoperatively.Results: Visual analogue scale scores decreased similarly in both groups over time, however, there were no differences between groups at any time during the study period (estimated marginal means: 1.4 ± SEM 0.2 vs 1.9 ± SEM 0.2 for groups A and I, respectively, P = 0.124). Cumulative doses of postoperative morphine were 98 ± 37 vs 93 ± 33 mg for groups A and I, respectively (P = 0.628). Patient satisfaction with analgesia was high in both groups (9 ± 1 vs 9 ± 1, P = 0.93). Conclusion:Intravenous acetaminophen is a reasonable alternative to oral ibuprofen as an adjunct to morphine patient-controlled analgesia after Cesarean delivery. Objectif

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“…Five mice per group was determined to detect a 25% reduction in tumor size, with a statistical power (b) of .8 and a ¼ .05 (PS Power and Sample Size Calculations software 24 ). To account for variability of the orthotopic tumor model and early mortality, we used 10 mice/group.…”

Section: Sample Sizementioning

confidence: 99%

Thrombin induces osteosarcoma growth, a function inhibited by low molecular weight heparin in vitro and in vivo

Ichikawa

Cole

Magnussen

et al. 2011

Cancer

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BACKGROUND: Procoagulant states, leading to activation of the coagulation protease thrombin, are common in cancer and portend a poor clinical outcome. Although procoagulant states in osteosarcoma patients have been described, studies exploring osteosarcoma cells' ability to directly contribute to procoagulant activity have not been reported. This study explores the hypothesis that osteosarcoma can regulate thrombin generation and proliferate in response to thrombin, and that attenuating thrombin generation with anticoagulants can slow tumor growth. METHODS: Pathologic analysis of osteosarcoma with adjacent venous thrombus was performed. In vitro proliferation assays, cell-based coagulant activity assays, and quantification of coagulation cofactor expression were performed on human and murine osteosarcoma cell lines with varying aggressiveness. The efficacy of low molecular weight heparin (LMWH) attenuation of tumor-dependent thrombin generation and growth in vitro and in vivo was determined. RESULTS: Venous thrombi adjacent to osteosarcoma were found to harbor tumor surrounded by fibrin expressing coagulation cofactors, a finding associated with poor clinical outcome. More aggressive osteosarcoma cell lines had greater surface expression of procoagulant factors and generated more thrombin than less aggressive cell lines and were found to proliferate in response to thrombin. Treatment with LMWH reduced in vitro osteosarcoma proliferation and procoagulant activity as well as tumor growth in vivo. CONCLUSIONS: These findings suggest that elements of the coagulation cascade may play a role in and represent a pharmaceutical target to disrupt osteosarcoma growth. They also have broader implications, as they suggest that, to be effective, dosing of anticoagulants must take into account an individual tumor's capacity to generate thrombin. Cancer 2012;118:2494

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Power and Sample Size Calculations for Studies Involving Linear Regression

Cited by 911 publications

References 5 publications

A genetic variant in the pre-miR-27a oncogene is associated with a reduced familial breast cancer risk

A genetic variant in the pre-miR-27a oncogene is associated with a reduced familial breast cancer risk

Intravenous acetaminophenvs oral ibuprofen in combination with morphine PCIA after Cesarean delivery

Thrombin induces osteosarcoma growth, a function inhibited by low molecular weight heparin in vitro and in vivo

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