Age, continent of study origin, zinc salt and risk of bias contributed significantly to between studies heterogeneity.
In addition, analyses by continent of study (Europe, North America, or other) yielded consistent, positive associations between PM2.5 and lung cancer.
The association between total alcohol intake (none, any regular consumption) and risk of ovarian carcinoma varied somewhat across studies following multivariable adjustment; the source of heterogeneity was within the three European studies when evaluated by continent of study origin (within-group heterogeneity: Europe, I 2 =75%; North America, I 2 =0%).
This notion is also indirectly supported by our observations that a significant benefit of zinc is not universally observed across continents of study origin or countries classified on the basis of economy both of which may somewhat reflect the heterogeneity in the microbiological spectrum of causative organisms.
The user can restrict the search by gene or allele, country of origin of studied samples, continent of origin of studied samples or studied disease.
No significant between-group difference was found for continent of residence, study quality, age category, and sex.
The great Gregor Piatigorsky advised her, as a child of Jewish parents at a time of turmoil on the continent, to study in London.
Stratified analyses were performed to evaluate the influences of selected study quality and participant characteristics on study results (10): sex, mean age at baseline, different definitions of MetS, depression measure, continent of origin, and study quality.
Continent, gender and time of study did not contribute to heterogeneity (Results not shown, disease specific Galbraith plots included in Figures S1, S2, S3, S4).
Meta-analyses were also conducted for subdivisions of the studies by continent, type of ST, study type (prospective or case-control) and smoking group.
On the other hand, ϕ = 1 indicates that there is a complete association between the degree of replicability and the continent of origin of the studied populations, that is, that replicabilities were discordant between continents (e.g. the replicability was 0% in European studies and 100% in East Asian studies).
