Given a summary table from a study, how do you calculate the combined mean age with standard deviation across the groups?
| Diagnosis | n | Mean age |
|---|---|---|
| A | 62 | 43.9 ± 15.3 |
| B | 11 | 46.3 ± 13.8 |
| C | 12 | 40.7 ± 14.6 |
Follows algorithm by Chan, Tony F.; Golub, Gene H.; LeVeque, Randall J. (1979), "Updating Formulae and a Pairwise Algorithm for Computing Sample Variances." (PDF), Technical Report STAN-CS-79-773, Department of Computer Science, Stanford University. and credits to previous implementation here.
Created as a proof of concept to help calculate aggregate statistics in meta studies.
