Table 1 Characteristics of studies and quality evaluation. ISAAC = international study of asthma and allergies in childhood, BMI = body mass index, OR = odds ratio.
Author | Country | Study design | Sample size | Age (y) | Diagnostic mode | Adjusted for confounders |
|---|---|---|---|---|---|---|
Nafstad 200042 | Norway | Cohort Study | 3,754 | 0–4 | Clinical diagnosis | Crude OR |
Mckeever 200243 | England | Cohort Study | 24,690 | 0–11 | Clinical diagnosis | Sex, age(y), prematurity, parental atopy history, parental smoking behavior, maternal age, general practice |
Negele 200444 | Germany | Cohort Study | 2,500 | 0–2(< 2) | Questionnaire (self-made), Clinical diagnosis | sex, study area, parental atopy history, maternal smoking, breast-feeding |
Renz-Polster 200519 | America | Cohort Study | 8,953 | 3–10 | Clinical diagnosis | Sex, age at diagnosis, birthweight, birth order, exposure to antibiotics in the postpartum period, ethnicity, multiple gestation, maternal age, education, marital status, smoking status during pregnancy, use of asthma and/or hay fever medications |
Salam 200620 | America | Cohort Study | 3,464 | 8–17 | Questionnaire (self-made) | Age, sex, race, birth order, birth weight, community of residence, parental education, health insurance coverage, parental atopy history, exposure to in utero smoking, maternal age at childbirth, requirement for special care after birth, calendar period of birth, and history of pneumonia, bronchitis, bronchiolitis, and croup |
Pistiner 200823 | America | Cohort Study | 432 | 0–9(< 9) | Questionnaire (self-made), Clinical diagnosis | Age and sex, birth weight, Endotoxin levels, ≤ 3 Episodes of nasal catarrh in the first year of life, day care attendance in the first year of life |
Park 201045 | South Korea | Cross-Sectional Study | 279 | < 6 | Clinical diagnosis | Sex, age, gestational age, birth weight, breast-feeding |
Huang 2014 21 | China | Case–control Study | 854 | 5–14 | Clinical diagnosis | Sex, gestational age, birth weight, breast-feeding, family smoking before and after birth, family smoking at present, housing floors, domestic pets, mildew and carpet in the home, antibiotic use within 1 year old, parental atopy history |
Li 201546 | China | Cross-Sectional Study | 20,803 | 5–13 | Questionnaire(ISAAC) | Age, sex, family income, family numbers, resident area per capita, parental education level, city |
Brandao 201622 | Brazil | Cross-Sectional Study | 672 | 0–6(< 6) | Questionnaire(ISAAC) | Gestational age, birth weight, breast-feeding, mother’s smoking during pregnancy, family income, mother’s schooling level, parity, number of persons who sleep in the room with the child, attendance to nursery to the age of 2 years, pneumonia ever |
Chu 201747 | China | Cross-Sectional Study | 12,639 | 5–12 | Questionnaire (self-made) | Maternal education level, paternal education level, maternal history of diabetes in pregnancy |
Loo 2017 48 | Singapore | Cohort Study | 1,237 | 0–5(< 5) | Questionnaire (self-made), Clinical diagnosis | Age, ethnicity, educational level, parity, parental atopy history, gestational diabetes mellitus status, early pregnancy body, offspring sex, gestational age |
Gerlich 201814 | Germany | Cohort Study | 1,006 | 9–11 | Questionnaire(ISAAC) , Clinical diagnosis | Sex, parental education, study location, place of birth, parental atopy history, presence of siblings, maternal smoking during pregnancy, season of birth |
Krzych-Fałta 201817 | Poland | Cross-Sectional Study | 9,231 | 6–7 13–14 | Questionnaire(ISAAC) , Clinical diagnosis | Unknown |
Zeng 201849 | China | Case–control Study | 296 | 4–14 | Clinical diagnosis | Parental atopy history, domestic animals, disease duration ≥ 24 months, asthma, seafood consumption, second-hand smoke smoking, breast-feeding |
Han 201916 | South Korea | Cohort Study | 1,374 | 4–12 | Clinical diagnosis | Age and sex, breast-feeding, number of siblings, parental atopy history, living area |
Yu 201950 | China | Cross-Sectional Study | 183,449 | 6–18 | Questionnaire (self-made) | Age, Year, sex, breast-feeding, father smoking |
Gorris 202015 | Ecuador | Cross-Sectional Study | 400 | 3–12 | Questionnaire(ISAAC) | Crude OR |
Mitselou 202018 | Sweden | Cohort Study | 1,059,600 | 0–13 | Clinical diagnosis | Sex, maternal age at delivery, country of birth, parity, maternal BMI, early pregnancy smoking and parental atopy history |
Richards 202051 | America | Cohort Study | 117,768 | 6–10 | Clinical diagnosis | Maternal age, education, race, pre-pregnancy BMI, smoking, antibiotics during pregnancy, parental atopy history, sex, gestational age, birth weight, NICU admission, birth order, breast-feeding |
Hu 202152 | China | Cross-Sectional Study | 10,464 | 6–11 | Questionnaire(ISAAC) | Sex, age, socioeconomic status, only one child in the household, parental atopy history |
Meza-Lopez 202153 | Mexico | Cross-Sectional Study | 1,003 | 6–7, 13–14 | Questionnaire(ISAAC) | Unknown |
