Hi to everybody,

I use the command metaprop (My effect size is "Prevalence of a skin disease")
Study Prevalence of a skin disease 95%ic 95%ic %weight
1 0.032 0.001 0.063 1.20
2 0.087 0.006 0.168 0.19
3 0.015 0.002 0.029 4.69
4 0.012 -0.012 0.036 1.87
5 0.029 -0.027 0.086 0.38
6 0.006 -0.005 0.017 5.88
7 0.005 -0.005 0.016 6.25
8 0.063 -0.006 0.131 0.26
9 0.002 0.000 0.004 13.36
10 0.0018 0.001 0.036 3.15
11 0.013 -0.012 0.037 1.79
12 0.003 0.002 0.005 13.58
13 0.014 0.011 0.017 12.45
14 0.002 0.001 0.003 13.71
15 0.022 -0.008 0.052 1.28
16 0.001 -0.000 0.002 13.59
17 0.005 -0.005 0.015 6.40

My question is: How is it possible, How can explain that in some studies the lower bound of the confidence interval is negative? I wonder this because the effect size is a prevalence.
Thank you all!!!

Tommaso