Dried blood spots: An evaluation of utility in the field

Background: Use of dried blood spots (DBS) offers advantages over serum samples in studies conducted in resource-poor settings. The aim of this study was to compare the number of adequate spots collected across different demographic groups. Methods: Five DBS were collected from 3316 individuals aged 0–49 years in Tianjin, China for a measles antibody study; DBS were rated “adequate” or “inadequate.” Linear regression, with the number of adequate DBS on a card as the outcome variable, was used to test for predictors of DBS adequacy. Results: There were 0 adequate DBS for 23% of participants and 5 adequate DBS for 24%. Mean number of adequate DBS was 1.68 in infants (