Table 1

 Characteristics of 15 publications included in meta-analysis of TNFα-308 polymorphism and asthma susceptibility

ReferenceCountryEthnicityAgeSource of cases (n)Source of controls (n)Asthma definitionHardy-Weinberg equilibrium
ISAAC, International Study of Asthma and Allergies in Childhood; TDI, toluene di-isocyanate; BHR, bronchial hyperresponsiveness.
Moffatt6AustraliaCaucasian5–51 yearsGeneral population
>(92)
General population without asthma (318)Respiratory questionnaireYes
Chagni9CanadaCaucasian<50 yearsHospital patients (251)Blood donors (252)Asthma severityYes
Li Kam Wa10UKMixed race18–70 yearsLocal community (246)Random individuals
>(310)
Symptom, BHRYes
Louis11BelgiumCaucasian17–74 yearsHospital outpatient clinic (95)Hospital workers and blood donors (98)Symptoms, BHR or positive airway reversibilityYes
Winchester12UKCaucasian,
>South Asian
AdultsHospital clinic (26)Non-asthmatics (691)History of childhood asthmaYes
Zhu13CanadaCaucasianInfantsHospital clinic (12)Non-asthmatics (269)SymptomYes
Witte15USAMixed race28–56 yearsOutpatient clinic (236)Non-asthmatics (275)Doctor’s diagnosis with positive airway reversibilityYes
Buckova16CzechCaucasian14–44 yearsPractitioners’ offices
>(151)
Controls without atopy, lung disorders (155)ATS diagnosis criteriaYes
Gao17ChinaChineseAdultsHospital pulmonary clinic (125)Healthy controls (96)Doctor’s diagnosis with BHR and/or positive airway reversibilityYes
Di Somma18ItalyItalian11–58 yearsHospital clinic (70)Non-asthmatics (169)QuestionnaireYes
Beghe19ItalyItalianAdultsPulmonary clinics
>(142)
Asymptomatics exposed to TDI (50)TDI-induced asthmaNo (p = 0.018)
Sandford21HongkongChinese10 yearsISAAC phase II study (107)Schoolchildren (118)Questionnaire, spirometry, BHR testingYes
Shin22KoreaKorean7–80 yearsAsthma research centre
>(550)
Normal subjects excluding asthma (171)Doctor’s diagnosis with BHR and/or positive airway reversibilityYes
Wang23ChinaChineseChildrenHospital clinics (191)Community population (138)QuestionnaireYes
Bilolikar24UKCaucasian2–17 yearsHospital respiratory clinics (115)Normal controls (156)Doctor’s diagnosisYes