Description

The first day of the course is targeted at the basic concepts (measures of effect size, heterogeneity, publication bias, trim and fill method, etc.).  Pitfalls in the data collection and coding will also be tackled (e.g., problems with retrieving studies, analyzing multiple outcome measures, multiple treatment arms, multiple follow-up moments, different measures etc.). In addition, the participants perform basic meta-analyses in the program R (R-package metafor; Viechtbauer, 2002) on example data sets. Some exercises can also be performed in Comprehensive Meta-Analysis (Borenstein, 2009). The second day is targeted at more advanced aspects of meta-analysis (meta-regression with multiple moderators, multilevel meta-analysis, interactions between moderators, meta-CART) and new developments in meta-analysis. Each day consists of a mixture of lectures and hands-on exercises.

After this course, you are able to
•    understand and explain the basic concepts of meta-analysis: measures of effect-size, fixed-effect  and random-effects models, (methods to assess) publication bias, forest plot.
•    understand and explain more advanced topics: methods to assess and explain effect size heterogeneity, meta-regression, multilevel meta-analysis, and meta-CART.
•    perform in R: basic meta-analysis, (multilevel) meta-regression, publication bias analysis, forest plot,  and meta-CART. 

Mode of instruction

Read one article that will be sent before the start of the course and for those not familiar with R some intro material to R.

Reading list

• ​​​​​​Book:  Borenstein, M., Hedges, L. V., Higgins, J. P., & Rothstein, H. R. (2009). Introduction to Meta-Analysis. Chichester:  Wiley & Sons.
• Assink, M., & Wibbelink, C. J. (2016). Fitting three-level meta-analytic models in R: A step-by-step tutorial. The Quantitative Methods for Psychology, 12(3), 154-174.
• Li, X., Dusseldorp, E., Su, X., & Meulman, J. J. (2020). Multiple moderator meta-analysis using the R-package Meta-CART. Behavior Research Methods, 52(6), 2657-2673.
• Other articles to be announced.

Fees

Target group	One day	Two days	Three days
PhD candidates FSW/FGGA	FREE	FREE	FREE
Staff FSW	€300	€400	€500
Other Leiden University PhD candidates	€215	€315	€415
Externals*	€450	€600	€750

*Externals are PhD candidates related to staff members of FSW (buitenpromovendi) and/or staff members of other Leiden University Faculties.

Entry requirements

-    bring your own laptop with R (and R-studio) (and optionally Comprehensive Meta Analysis);
-    those who are more experienced in meta-analysis may skip the first day of this course. If in doubt, please contact the coordinator.