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                         estimate      se     tval    pval    ci.lb    ci.ub 
intrcpt                     0.6952  0.0796   8.7313  <.0001   0.5232   0.8672  *** 
participantsyounger kids   -0.4279  0.1501  -2.8513  0.0136  -0.7521  -0.1037    * 

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Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

I ran a meta regression for my meta-analysis. I divided the participants into younger kids and older kids and the results showed that both groups are significant as the p-value is less than 0.05. How should I report this data?

If I understood it correctly, the intrcpt value is for the older kids group. Is this correct?

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    $\begingroup$ If you specified it as you claim, then yes, the intercept is the base value for the older kids. For the younger kids the estimate is intrcpt + participantsyounger kids. $\endgroup$
    – user2974951
    Commented Jul 11, 2019 at 6:14
  • $\begingroup$ My interpretation is simply that you estimates correctly and beyond random variability the effect of your study (I guess a treatment) in older subjects... This is what the intercept tells you... $\endgroup$
    – Giuseppe Biondi-Zoccai
    Commented Jul 11, 2019 at 6:46
  • $\begingroup$ @user2974951Thank you for your reply! How about the p-value in older kids group? Where can I find this information? Thanks! $\endgroup$
    – Josee Luis
    Commented Jul 12, 2019 at 8:02

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Because you coded older and younger kids as a factor, lm automatically created dummy variables. The first level of your factor is older kids, this is your reference level, and is estimated in the intercept term intrcpt, which is equal to 0.6952.

The effect of the younger kids (the second level) is estimated in the participantsyounger kids term, however, this is estimated as the difference from the reference level. To get the estimate of the younger kids you do intrcpt + participantsyounger kids.

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  • $\begingroup$ Thank you! How about the p-value in the older kids group? Where can I find this information? $\endgroup$
    – Josee Luis
    Commented Jul 12, 2019 at 8:00
  • $\begingroup$ @M.L The p-values do not need to be added, they are in the right place already, so the p-value for the older kids is <.0001 while for the younger it is 0.0136. $\endgroup$
    – user2974951
    Commented Jul 12, 2019 at 8:02
  • $\begingroup$ Thank you! So does it mean that both groups are statistically significant? $\endgroup$
    – Josee Luis
    Commented Jul 12, 2019 at 8:14
  • $\begingroup$ @M.L Yes, the older kids estimate is significantly different from zero, while the younger kids are significantly different from the older kids. $\endgroup$
    – user2974951
    Commented Jul 12, 2019 at 8:15
  • $\begingroup$ Thanks! So the p-value for younger kids here is not the p-value across studies; instead, it is the comparison with the intrcpt group, is it correct? $\endgroup$
    – Josee Luis
    Commented Jul 12, 2019 at 8:39

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