Sample Size Estimation: How Many Individuals Should Be Studied?

Eng, John

doi:10.1148/radiol.2272012051

Cited by 635 publications

(481 citation statements)

References 7 publications

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“…23 Treatment allocation was determined by a statistician using block randomization with randomly varying block sizes of 2, 4, and 6 to ensure that both treatment arms had similar sample sizes. 24 Triple-dose nonflavored albendazole (400 mg) and placebo treatments (tablets matched in color, size, taste, and shape) were prepared by staff not involved in the field work, in sealed envelopes marked with unique identifiers.…”

Section: Methodsmentioning

confidence: 99%

Rapid Re-Infection with Soil-Transmitted Helminths after Triple-Dose Albendazole Treatment of School-Aged Children in Yunnan, People's Republic of China

Yap

Du²,

Fang-wei³

et al. 2013

The American Society of Tropical Medicine and Hygiene

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Abstract. Post-treatment soil-transmitted helminth re-infection patterns were studied as part of a randomized controlled trial among school-aged children from an ethnic minority group in Yunnan province, People's Republic of China. Children with a soil-transmitted helminth infection (N = 194) were randomly assigned to triple-dose albendazole or placebo and their infection status monitored over a 6-month period using the Kato-Katz and Baermann techniques. Baseline prevalence of Trichuris trichiura, Ascaris lumbricoides, hookworm, and Strongyloides stercoralis were 94.5%, 93.3%, 61.3%, and 3.1%, respectively, with more than half of the participants harboring triple-species infections. For the intervention group (N = 99), the 1-month post-treatment cure rates were 96.7%, 91.5%, and 19.6% for hookworm, A. lumbricoides, and T. trichiura, respectively. Egg reduction rates were above 88% for all three species. Rapid re-infection with A. lumbricoides was observed: the prevalence 4 and 6 months post-treatment was 75.8% and 83.8%, respectively. Re-infection with hookworm and T. trichiura was considerably slower.

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Section: Methodsmentioning

confidence: 99%

Rapid Re-Infection with Soil-Transmitted Helminths after Triple-Dose Albendazole Treatment of School-Aged Children in Yunnan, People's Republic of China

Yap

Du²,

Fang-wei³

et al. 2013

The American Society of Tropical Medicine and Hygiene

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“…All subjects gave written informed consent for the MRI examination and the subsequent scientific evaluation of the data sets. The sample size was estimated according to Eng. Assuming an SD of 10 % and a minimum expected difference of 5 %, the sample size was calculated to be 7.85 [16].…”

Section: Subjectsmentioning

confidence: 99%

Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation

Kenkel

Wurnig

Filli

et al. 2016

Fortschr Röntgenstr

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Purpose: The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol. Materials and Methods: A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3?T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale. Results: Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9?%. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol. Conclusion: It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability. Key Points ??Whole-body diffusion-weighted imaging (WB-DWI) using simultaneous multi-slice and blipped-CAIPIRINHA reduces the measurement time strongly without having a significant impact on image quality. ??The reduction in measurement time might strongly contribute to the clinical applicability of WB-DWI. ??However, further refinement of the slice-accelerated EPI sequence, and the WB-DWI protocol applying this sequence type seems necessary; and the value of such WB-DWI protocols for assessment of systemic oncological diseases needs to be investigated in further clinical studies. Citation Format: ??Kenkel D, Wurnig MC, Filli L et?al. Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation. Fortschr R?ntgenstr 2016; 188: 381???388

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“…O tamanho da amostra foi determinado a partir de um estudo piloto previamente realizado, utilizando indivíduos que possuíam as mesmas características daquelas que foram empregadas no presente estudo, baseando-se em uma significância de 5% e um poder do teste de 80% 23 . A amostra foi composta por 14 homens saudáveis (idade: 25±4 anos, estatura: 175±4 cm, massa: 80±11 kg, distância biacrômial: 37±2 cm).…”

Section: Métodosunclassified

Efeito Agudo Da Ordem De Exercícios Tradicional E Pré-Exaustão No Treinamento De Força

Soares

Gomes

Paulodetto

et al. 2016

Rev Bras Med Esporte

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RESUMOIntrodução: Diferentes ordens no sequenciamento dos exercícios na musculação podem afetar o desempenho neuromuscular. Objetivo: Investigar o efeito da ordem dos exercícios de musculação (pré-exaustão, (PE) e tradicional, (TR) sobre o desempenho e atividade muscular de peitoral maior (PM) e tríceps braquial (TB) durante a realização dos exercícios de supino reto (SR) e tríceps na polia (TP). Métodos: A amostra foi composta de 14 homens treinados (idade: 25±4 anos, estatura: 175±4 cm, massa: 80±11 kg). O experimento foi conduzido em duas sessões. Na primeira, foi realizada a familiarização e determinação de 10 repetições máximas (RM) nos exercícios SR e TP. A segunda foi dividida em duas fases. A primeira fase avaliou o desempenho dos exercícios isoladamente, considerado o controle (CON). A segunda fase, avaliou duas diferentes ordens de exercícios: pré-exaustão, PE (TP e SR) e tradicional, TRAD (SR e TP). Foram avaliados o desempenho e a atividade muscular do PM e TB. One-way ANOVA foi utilizada para comparar as condições. ANOVA (2x3) de medidas repetidas foi utilizada para comparar a atividade muscular. Resultados: Os resultados demonstraram um menor número de RM no TP na condição TRAD em comparação com CON e PE. Foi observado um menor número de RM no exercício SR na condição PE em comparação com CON e TRAD. Quanto à atividade muscular avaliada pela eletromiografia integrada não foram observadas diferenças significantes para PM e TB durante a realização dos exercícios em todas as condições. Conclusão: Conclui-se que em ambas as estratégias o número de RM realizadas no segundo exercício foi reduzida, entretanto não foram observadas alterações na ativação dos músculos principais de cada exercício.Descritores: eletromiografia, força muscular, treinamento de força. : pre-exhaustion, PE (TE and BP) and traditional, TRAD (BP and TE). ABSTRACT Introduction: Different orders in exercise sequences during resistance training can affect neuromuscular performance. Objective: To investigate the effect of resistance training exercises (pre-exhaustion and traditional) on the performance and muscle activity of pectoralis major (PM) and triceps brachii (TB) during execution of bench press (BP) and triceps extension (TE) exercises. Methods: The sample was composed by 14 trained men (age: 25±4 years, height: 175±4 cm, weight: 80±11 kg). The experiment was carried out in two sessions. In the first, familiarization and determination of 10 repetition maximum (RM) of BP and TE exercises were carried out. The second was divided in two phases. The first evaluated exercise performance separately (control condition, CON). The second evaluated two different exercise orders

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Sample Size Estimation: How Many Individuals Should Be Studied?

Cited by 635 publications

References 7 publications

Rapid Re-Infection with Soil-Transmitted Helminths after Triple-Dose Albendazole Treatment of School-Aged Children in Yunnan, People's Republic of China

Rapid Re-Infection with Soil-Transmitted Helminths after Triple-Dose Albendazole Treatment of School-Aged Children in Yunnan, People's Republic of China

Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation

Efeito Agudo Da Ordem De Exercícios Tradicional E Pré-Exaustão No Treinamento De Força

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