Main analysis | DS1 | DS2 | |
N | 211 | 131 | 115 |
Reporting of the no of missing data of covariates of interest | 36 (17%) | 22 (17%) | 20 (17%) |
Reporting of the method to handle missing data | 63 (30%) | 39 (30%) | 36 (31%) |
Handling of missing data* | |||
Complete case | 31 (15%) | 18 (14%) | 16 (14%) |
Multiple imputation | 21 (10%) | 13 (9%) | 12 (10%) |
Last observation carried forward | 7 (3%) | 4 (3%) | 4 (3%) |
Supplementary category | 2 (1%) | 2 (2%) | 2 (2%) |
Other | 5 (3%) | 3 (2%) | 3 (3%) |
DS1: Dataset 1 includes only studies where the comparison of at least two treatments was the main exposure of interest (head to head studies).
DS2: Dataset 2 includes only studies from DS1, which had no other outcome than effectiveness.
*Sum of the methods may be greater than the numbers of studies as some studies used several methods.