Within-person variance in biochemical indicators of iron status: effects on prevalence estimates.
Am J Clin Nutr
; 52(3): 541-7, 1990 Sep.
Article
em En
| MEDLINE
| ID: mdl-2393013
ABSTRACT
The effect of within-person variance on prevalence estimates from population distributions based on a single measurement was examined for hematologic and iron-status indicators collected in the Hispanic Health and Nutrition Examination Survey (HHANES). Within-person to between-person variance ratios (WBs) were estimated for 11 indicators by using data from 80 persons who provided blood twice in HHANES. Distributions of selected iron-status indicators from 20-44-y-old Mexican American females from HHANES were adjusted for within-person variance by using the WB estimates, and prevalences of low values based on the original and adjusted distributions were compared. WB were less than 1 for the majority of the indicators. Nonetheless, prevalences of low values from the original distributions were inflated when commonly used cutoff values were applied. Within-person variance in serum analytes needs to be controlled when the prevalence of a condition in populations is assessed.
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Base de dados:
MEDLINE
Assunto principal:
Anemia Hipocrômica
Idioma:
En
Ano de publicação:
1990
Tipo de documento:
Article