# Graph trend line from meta-analysis (multiple pooled studies)

**URL:** <https://discourse.datamethods.org/t/graph-trend-line-from-meta-analysis-multiple-pooled-studies/3651>\
**Category:** meta-analysis\
**Created:** [August 17, 2020, 4:15pm UTC](https://discourse.datamethods.org/t/graph-trend-line-from-meta-analysis-multiple-pooled-studies/3651 "2020-08-17T16:15:06Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![plagoniste](https://discourse.datamethods.org/letter_avatar_proxy/v4/letter/p/5f9b8f/32.png) [@plagoniste](https://discourse.datamethods.org/u/plagoniste)\
**Post date:** [August 17, 2020, 4:15pm UTC](https://discourse.datamethods.org/t/graph-trend-line-from-meta-analysis-multiple-pooled-studies/3651/1 "2020-08-17T16:15:06Z")

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Hi! I have searched the web and have found no convincing answer, although this should be pretty easy. My question separates into 2:  
1- Is it reasonable to trace a trend line of the evolution of a parameter over time from the pooling of different studies, each of which do not contain all time points (although all studies are included in the pre-intervention group and all studies have similar inclusion/exclusion criteria)? See the pictures below for exemple: the forest plot picture shows all the different studies’ contribution to each time point. Then I compute a graph from the mean ± SD of each time point, with a trend line. Is this heresy?  
2- If this is acceptable, can we (and how do we) compare these time point changes among each other?  
Thanks!

 ![MA forest plot](https://discourse.datamethods.org/uploads/default/original/2X/e/e0488f8e78942dc10f540833a31bbe8cc21ce6e8.jpeg)