Table 3 The three previous studies used for comparisons

Wu et al., 1993[12]

(1) 481 participants, aged 1-17 years, from a southern Taiwan village.

(2) 1100 students randomly selected from 24251 elementary and junior middle school students in Tainan City.

EIA (HAVAB-EIA, Abbott Laboratories, North Chicago, IL)

Liu et al., 1994[7]

(1) 164 children under 3 years of age brought to the well-baby clinic.

(2) 87 preschool children age 3-6 years from 3 kindergartens.

(3) 311 children aged 6-16 years from two primary schools and one junior high school.

(4) 176 adults, ranging from 16 to 67 years of age, including 34 pregnant women, recruited during health examination or prenatal care in the hospital.

RIA (HAVAB, Abbott Laboratories, North Chicago, IL)

Wang et al., 2001[8]

(1) 61 children under aged from well-baby clinic at the hospital.

(2) 150 preschool children aged 3-6 years from three kindergartens.

(3) 345 children, aged 6-12 years, from two primary schools.

(4) 92 students selected at random from a junior high school.

(5) 341 adults, 20-63 years of age, enrolled from health examination or prenatal care at the National Cheng Kung University Hospital.

RIA (HAVAB, Abbott Laboratories, North Chicago, IL)