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A
.gov website belongs to an official
government organization in the United States.
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A lock (
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connected to the .gov website. Share sensitive
information only on official, secure websites.
Funnel plot for risk of bias. Asymmetric funnel plot has evidence of some risk of bias. Precise studies (i.e., those with larger samples) are indicated at the top of the chart and deviate from the grand mean effect. Mid-size studies cluster around the mean effect size
