Intra-class correlation estimates for assessment of vitamin A intake in children.
J Health Popul Nutr
;
2005 Mar; 23(1): 66-73
Artigo
em Inglês
| IMSEAR
| ID: sea-767
ABSTRACT
In many community-based surveys, multi-level sampling is inherent in the design. In the design of these studies, especially to calculate the appropriate sample size, investigators need good estimates of intra-class correlation coefficient (ICC), along with the cluster size, to adjust for variation inflation due to clustering at each level. The present study used data on the assessment of clinical vitamin A deficiency and intake of vitamin A-rich food in children in a district in India. For the survey, 16 households were sampled from 200 villages nested within eight randomly-selected blocks of the district. ICCs and components of variances were estimated from a three-level hierarchical random effects analysis of variance model. Estimates of ICCs and variance components were obtained at village and block levels. Between-cluster variation was evident at each level of clustering. In these estimates, ICCs were inversely related to cluster size, but the design effect could be substantial for large clusters. At the block level, most ICC estimates were below 0.07. At the village level, many ICC estimates ranged from 0.014 to 0.45. These estimates may provide useful information for the design of epidemiological studies in which the sampled (or allocated) units range in size from households to large administrative zones.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
População Rural
/
Vitamina A
/
Deficiência de Vitamina A
/
Humanos
/
Estudos Epidemiológicos
/
Análise por Conglomerados
/
Modelos Lineares
/
Avaliação Nutricional
/
Criança
/
Fatores de Risco
Tipo de estudo:
Estudo de etiologia
/
Estudo de incidência
/
Estudo observacional
/
Estudo prognóstico
/
Fatores de risco
País/Região como assunto:
Ásia
Idioma:
Inglês
Revista:
J Health Popul Nutr
Assunto da revista:
Gastroenterology
/
Nutritional Sciences
/
Public Health
Ano de publicação:
2005
Tipo de documento:
Artigo
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