Good evening, I want to do a meta-analysis of multiple subgroups.

Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input str50 studyid float(fm_event_n fm_event_tot fm_nonevent_n cont_event_n cont_event_tot cont_nonevent_n days_therapy type_therapy probiotic_sp)
"Bekar 2011"                                     36  46 10  18  36 18 2 1 .
"Deguchi 2012 (antibiotic-resistant)"            10  26 16   7  25 18 1 1 1
"Deguchi 2012 (antibiotic susceptible)"          65  70  5  58  67  9 1 1 1
"Guillemard 2021"                                57  68 11  60  68  8 2 2 2
"Kim 2008 (with nonulcer dyspepsia)"             87 113 26  88 121 33 1 1 2
"Kim 2008 (with peptic ulcer disease)"           46  55  9  41  58 17 1 1 2
"Mirzaee y Rezahosseini 2012 (without placebo)"  20  31 11  19  26  7 1 1 .
"Mirzaee y Rezahosseini 2012 (with placebo)"     19  31 12  19  26  7 1 1 .
"Sheu 2002"                                      73  80  7  63  80 17 1 1 2
"Srinarong 2014 (14-day therapy)"                25  25  0  24  25  1 2 2 2
"Srinarong 2014 (7-day therapy)"                 25  25  0  23  25  2 1 2 2
"Yasar 2010"                                     25  38 13  20  38 18 2 1 1
"Yoon 2010"                                     104 151 47 124 186 62 2 1 2
end
label values days_therapy days_therapy
label def days_therapy 1 "Seven days", modify
label def days_therapy 2 "Fourteen days", modify
label values type_therapy type_therapy
label def type_therapy 1 "Triple therapy", modify
label def type_therapy 2 "Quadruple therapy", modify
label values probiotic_sp probiotic_sp
label def probiotic_sp 1 "Single", modify
label def probiotic_sp 2 "Multiple", modify

I have tried the following syntax:


Code:
meta esize fm_event_n fm_nonevent_n cont_event_n cont_nonevent_n, esize(lnrratio) random(dlaird) studylabel(studyid)
meta summarize, eform(Risk ratio)
meta forestplot, subgroup(days_therapy type_therapy probiotic_sp) eform(Risk ratio) nullrefline(favorsleft("Favors control") favorsright("Favors Milk fermented")) columnopts(_K, title(Number of studies)) nooverall nogbhomtests noohomtest noohetstats nonotes

The problem is that all the subgroups have information from 13 studies, but one of them (probiotic_sp) only has information from 10 studies. When doing the meta-analysis, all the subgroups came out with only 10 studies. I appreciate any advice to solve this problem.

Thanks