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usepackage{amsmath}
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begin{landscape}
begin{table}[]
caption{Study characteristics.}
begin{adjustbox}{max width=23cm}
begin{threeparttable}

begin{tabular}{>{raggedright}p{2.5cm} >{raggedright}p{0.25linewidth} >{raggedright}p{0.2linewidth} >{raggedright}p{0.25linewidth} c c c l}

toprule
Study                            &
multicolumn{1}{l}{Intervention} &
multicolumn{1}{l}{Population}   &
multicolumn{1}{l}{Outcome}      &
k                                &
n                                &
begin{tabular}[c]{c}Effect size \ measureend{tabular} &
multicolumn{1}{c}{begin{tabular}[c]{c}Effect size \ {[}95% CI{]}end{tabular}}  \
midrule

Alford & Derzon (2012)         &
School-based interventions to reduce violence and antisocial behavior &
School-aged children and youths &
Physical aggression, antisocial behavior, aggressive/disruptive behavior, and delinquent behavior         &
41      &       --              &
g       &
0.133 {[}0.082, 0.184{]}tnote{**} \ addlinespace[0.2cm]

Anderson & Whiston (2005)      &
Sexual assault college education programs                             &
College students                &
Incidence of sexual assault perpetration &
--      &       --              &
d       &
0.101 {[}0.036, 0.167{]}tnote{*} \ addlinespace[0.2cm]

bottomrule
end{tabular}

begin{tablenotes}[para,flushleft]
{small
textit{Note.} My notes. \
item[*] $p$ textless{} 0.05. item[**] $p$ textless{} 0.01.
}
end{tablenotes}
end{threeparttable}
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end{table}
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