PMC

sRRs (95% CIs) for strata of exposure assessment method, statistical analysis, source of controls, study area, and study design. The p-value from meta-regression represents the p-value of the F-test in case of more than two categories, whereas it represents the p-value for the t-test in the case of the two statistical analysis strata.

Forest plot for study-specific RRs and sRRs (95% CIs) of PD associated with the use of pesticides. The studies are ordered by publication year and stratified by studies that did or did not include nonoccupational exposure in the exposed group. Studies were pooled with the random effects method. The size of the squares reflects the statistical weight of the study in the meta-analyses.

Funnel plots of studies included in the meta-analysis for the risk of PD associated with the use of pesticides (A), herbicides (B), insecticides (C), and fungicides (D). Circles represent studies that included nonoccupational exposure in the exposed group, and triangles represent studies that were based on occupational exposure only. Egger’s test p-values were 0.057, 0.338, 0.208, and 0.680 for pesticide, herbicide, insecticide, and fungicide effect estimates, respectively.

Forest plots for study-specific RRs and sRRs (95% CIs) of PD associated with the use of herbicides (A), insecticides (B), and fungicides (C). The studies are ordered by publication year and stratified by studies that did or did not include nonoccupational exposure in the exposed group. Studies were pooled with the random effects method. The size of the squares reflects the statistical weight of the study in the meta-analyses.