An individual participant data meta-analysis (IPDMA) is a specific type of meta-analysis for which the original data for each participant in a study are collected, checked, and re-analyzed systematically. The IPDMA has also been described as the gold standard of systematic reviews because it can improve the completeness and quality of data and the breadth and flexibility of analysis.

In the PAINT-IPDMA project, we aim to gain more insight into psychosocial interventions for children and adolescents with ADHD and disruptive behaviors. We are conducting systematic reviews to identify which studies are relevant to incorporate individual participant data into our IPDMA.

Read more about the latest IPDMA publication and results:

Goal of the project

Many well-designed studies have investigated the effectiveness of psychosocial interventions for ADHD and disruptive behavior. However, only some studies had the opportunity to conduct well-powered moderator analyses. By combining all studies in this field, we can look into factors influencing treatment efficacy and identify subgroups of families who respond better or worse to specific interventions. Hopefully, this will lead to significant advances in personalized care for children with ADHD and disruptive behaviors.

Why perform an IPDMA?

An An IPDMA differs from aggregated data meta-analysis in that it uses the original participant data instead of results described in research articles. This method makes it possible to examine if a treatment is effective. Individual participant data has several advantages to aggregated data meta-analysis:

1. Statistical methods can be standardized across studies, reducing noise

2. A larger sample size allows testing of moderators of treatment effects and effects in subgroups in a much more reliable way than in individual studies

3. Greater power to test moderators of treatment compared to meta-regression used in aggregated data meta-analysis

4. Allows handling of missing data in the same way across trials

With an IPDMA, we can contribute considerably to developing personalized interventions for ADHD and disruptive behaviors.

What do we ask from the participants?

Once we identify all eligible studies, we will contact the corresponding authors to ask for their participation in the IPDMA. Principal investigators of eligible trials will be requested to send raw, anonymous data of all included participants from all eligible conditions (i.e., intervention and control conditions) and all assessment points. Only the transfer of individual trial data is necessary for participation in the IPDMA.

Future plans

We plan to establish an extensive individual participant database that includes a worldwide range of parenting intervention studies (not yet covered in our current IPDMAs) on the broad group of referred children with externalizing behavior problems, including children with and without ADHD, ODD, or CD diagnosis. Specifically, we will include any intervention that focuses their efforts on parents as the primary agents of change in child behavior. The aim is to gain more insight into the differential effectiveness of parenting interventions and identify optimal program content for individual children with externalizing problems.

Contact or Questions?

If you have any questions please feel free to contact or

The researchers

Dr. Annabeth Groenman
Accare Child Study Center

Constantina Psyllou
Accare Child Study Center

Dr. Marjolein Luman
Accare Child Study Center

Dr. Patty Leijten
Accare Child Study Center

Prof. dr. Saskia van der Oord
KU Leuven

Prof. dr. Barbara van den Hoofdakker
Accare Child Study Center


Latest publications

Attachment in children with ADHD

July 18th, 2022|0 Comments

In the general population, externalising behaviour seems to be associated with insecure attachment and lack of trust in caregiver support. Some studies in ADHD populations have shown that children with ADHD are more likely to [...]

Other Projects


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In PAINT-IPDMA, an individual participant data meta-analysis is being conducted on psychosocial treatments for children and adolescents with ADHD. In the follow-up IPDMA study, the psychosocial treatments for children and adolescents with behavioural problems are investigated.


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