ABSTRACT
ABSTRACT: Introduction: This paper details the methods used in the second national Biological and Behavioral Surveillance Survey (BBSS) of HIV, syphilis, and hepatitis B and C among men who have sex with men in Brazil. Methods: Respondent-driven sampling (RDS) was used in 12 cities in 2016. The targeted sample size was initiated with five to six seeds in each city. HIV, syphilis, and Hepatitis B and C rapid tests were offered to participants. RDS Analyst with Gile's successive sampling (SS) estimator was used to adjust results as recommended and a weight for each individual was generated for further analysis. Data for the 12 cities were merged and analyzed using Stata 14.0 complex survey data tools with each city treated as its own stratum. Results: Duration of data collection varied from 5.9 to 17.6 weeks. 4,176 men were recruited in the 12 cities. Two sites failed to achieve targeted sample size due to a six-month delay in local IRB approval. No city failed to reach convergence in our major outcome variable (HIV). Conclusion: The comprehensive BBSS was completed as planned and on budget. The description of methods here is more detailed than usual, due to new diagnostic tools and requirements of the new STROBE-RDS guidelines.
RESUMO: Introdução: Este artigo detalha os métodos utilizados na segunda Pesquisa Nacional de Vigilância Biológica e Comportamental (BBSS) do HIV, sífilis e hepatite B e C entre os homens que fazem sexo com homens no Brasil. Métodos: O método Respondent-driven Sampling (RDS) foi utilizado em 12 cidades em 2016. A amostra foi iniciada com cinco a seis sementes em cada cidade. Testes rápidos para o HIV, sífilis e Hepatite B e C foram oferecidos aos participantes. O software RDS Analyst com o estimador de amostragem sucessiva (SS) de Gile foi utilizado para ajustar os resultados como recomendado, gerando um peso para cada indivíduo para análises. Osdados das 12cidades foram unidos em um único banco e analisados usando as ferramentas de dados complexos do Stata 14.0, com cada cidade sendo tratada como seu próprio estrato. Resultados: A duração da coleta de dados variou de 5,9 a 17,6 semanas e 4.176 homens foram recrutados nas 12 cidades. Dois sites não alcançaram o tamanho da amostra alvo devido a uma demora de seis meses na aprovação local do Comitê de Ética. Todas as cidades atingiram a convergência na principal variável estudada (HIV). Conclusão: O BBSS foi representativo e concluído conforme planejado e dentro do orçamento. A descrição dos métodos aqui é mais detalhada do que o habitual, devido às novas ferramentas e requisitos de diagnóstico das novas diretrizes do STROBE-RDS.
Subject(s)
Humans , Male , Adult , Syphilis/diagnosis , HIV Infections/diagnosis , Hepatitis C/diagnosis , Homosexuality, Male/statistics & numerical data , Hepatitis B/diagnosis , Brazil/epidemiology , Syphilis/epidemiology , HIV Infections/epidemiology , Population Surveillance , Prevalence , Surveys and Questionnaires , Health Surveys/methods , Hepatitis C/epidemiology , Self Report , Hepatitis B/epidemiologyABSTRACT
Field experiment should be carried out with high accuracy since the discarding of a trial involves waste of time and resources, and can mislead breeders in selecting inferior genotypes. The simulation of a large number of experiments with great variability of traits is the main strategy to assist breeders on how to perform the experiment. Therefore, the objective of this study was to evaluate two criteria to infer the experimental quality: Coefficient of Variation (CV) and repeatability coefficient. Experimental data from evaluations of common bean lines carried out in 104 experiments were used in this study. The simulation of the scenarios used the following parameters: number of cultivars, number of blocks, genetic variance, mean yield, and coefficient of variation. Two thousand replications for each scenario were simulated. Genotypes means were arranged in an order, and the Spearman correlation was obtained between the estimated genotypes mean and the true genotypic values. Results revealed that CV is not a reliable parameter to evaluate the quality of experiment in the field. In conclusion, repeatability coefficient is the parameter that defines the discarding criteria of evaluation experiments and the recommendation of cultivars, as long as the values for each response variable are established.
A decisão de descartar um experimento envolve um grande desperdício de tempo e dinheiro e, portanto, e os experimentos de campo precisam ser desenvolvidos com a maior acurácia possível para que o melhorista não selecione genótipos inferiores. A simulação de um grande número de experimentos e características é a príncipal estratégia para ajudar os melhoristas na montagem dos experimentos. O objetivo deste trabalho foi avaliar dois critérios para verificar a eficiência de um experimento: Coeficiente de variação (CV) e coeficiente de repetibilidade. Dados de 104 experimentais de avaliação de linhagens de feijoeiro foram utilizados. Para a simulação dos experimentos, os seguintes parâmetros foram considerados: número de cultivares, número de blocos, variância genética, média de produtividade e coeficiente de variação. Foram simuladas 2000 repetições para cada cenário. As médias dos genótipos foram ordenadas e a correlação de Spearman entre os valores observados e os valores genotípicos reais foram obtidas. Os resultados revelaram que o CV não é um estimador confiável para a avaliação da qualidade do ensaio em experimentos de campo. Concluiu-se que o coeficiente repetibilidade é o parâmetro que possibilitará definir critérios mais precisos de descarte de experimentos de avaliação e recomendação de cultivares.
Subject(s)
Crop Production , Data Interpretation, Statistical , Phaseolus , GenotypeABSTRACT
Objective The aim of this study was to assess the current situation and master degree on medical statistics among the medical correlation personnel, in order to provide useful information for transformation of education towards the medical correlation personnel . Methods Using cluster random sampling method to select 358 the medical correlation personnel who were recruited from health institutions in Chongqing to respond to the questionnaires. Questionnaire including respondent basic information, statis-tical knowledge and statistical knowledge needs. The data of the survey were analyzed by chi-square test, descriptive statistics analysis. Results 94.7% of the surveyed used statistical knowledge in the process of work or study. The main concentration of medical statistical knowledge utilization rate, the proportion of receive professional education or training courses of medical statistics and the willingness to participate in specialized training of medical statistics is 20-30 age group, No Title group, Master and over group andStudents group. As for ten categories of common statistical methods, thirty percent of people can use them skillfully, but the majority of the more advanced statistical analysis methods cannot be used or have never heard of. The greatest demand for learning ten kinds of common statistical methods is calculating cor-rectly through statistical software. Conclusion The vast majority of medical personnel need to use medical statistics in the actual work and study, but they have a lower mastery of statistical methods. Therefore, we should strengthen the medical statistics teaching and training for medical personnel.