Table 2 Handling of missing data in primary analysis among 73 trials who reported missing outcome data
From: Handling missing data in RCTs; a review of the top medical journals
N (%)1 | |
|---|---|
Proportion of patients with missing outcome1 | |
No missing data | 4 (5) |
0 – 1% | 2 (3) |
1 – 5% | 11 (14) |
5 – 10% | 24 (31) |
> 10% | 36 (47) |
Reported number of patients with missing outcomes by randomized treatment arm | 71 (97) |
Reported reasons why missing | 66 (90) |
Mentioned attempts to avoid missing data before and during trial | 26 (36) |
Methods | |
Complete case | 33 (45) |
Simple imputation | |
Linear interpolation | 3 (5) |
Worst-case | 8 (11) |
LOCF | 9 (12) |
Multiple imputation | 6 (8) |
Model based | |
GEE (un-weighted) | 3 (4) |
Mixed model/hierarchical/multilevel | 11 (15) |