Table 1.
Sample statistics and psychometric properties of Geriatric Depression Scale and MDS Depression Rating Scale.
| Sample statistic or psychometric property | Cognitively Impaired Group (n = 495) | Cognitively Intact Group (n = 209) | All Participants (N = 704) |
| Number (%) with missing data on all items | |||
| GDS-15 | 81 (16%) | 35 (17%) | 116 (16%) |
| GDS-5 | 110 (22%) | 5 (2%) | 115 (16%)* |
| E1SUM | 3 (1%) | 2 (1%) | 5 (1%) |
| DRS | 0 (0%) | 0 (0%) | 0 (0%) |
| Number (%) with complete data on all items | |||
| GDS-15 | 139 (28%) | 111 (53%) | 250 (36%)* |
| GDS-5 | 223 (45%) | 157 (75%) | 380 (54%)* |
| E1SUM | 492 (99%) | 207 (99%) | 699 (99%) |
| DRS | 494 (100%) | 209 (100%) | 703 (100%) |
| Number (%) with majority of scale items not missing | |||
| GDS-15 | 357 (72%) | 203 (97%) | 560 (80%)* |
| GDS-5 | 352 (71%) | 200 (96%) | 552 (78%)* |
| E1SUM | 495 (100%) | 209 (100%) | 704 (100%) |
| DRS | 495 (100%) | 209 (100%) | 704 (100%) |
| Mean* (SD) | |||
| GDS-15 | 4.7 (3.5) | 4.9 (3.4) | 4.8 (3.5) |
| GDS-5 | 2.0 (1.5) | 2.1 (1.6) | 1.5 (1.6) |
| E1SUM | 3.9 (3.8) | 2.7 (3.4) | 3.6 (3.7)* |
| DRS | 1.9 (2.1) | 1.8 (2.3) | 1.9 (2.2) |
| Proportion at floor | |||
| GDS-15 | 0.081 | 0.053 | 0.072 |
| GDS-5 | 0.166 | 0.167 | 0.166 |
| E1SUM | 0.206 | 0.349 | 0.249* |
| DRS | 0.356 | 0.397 | 0.368 |
| Alpha – internal consistency reliability – row-wise complete cases only | |||
| GDS-15 | 0.799 | 0.781 | 0.791 |
| GDS-5 | 0.609 | 0.597 | 0.602 |
| E1SUM | 0.695 | 0.738 | 0.708 |
| DRS | 0.542 | 0.672 | 0.583* |
| Alpha – internal consistency reliability – row-wise mean substitution for missing data† | |||
| GDS-15 | 0.825 | 0.798 | 0.814 |
| GDS-5 | 0.663 | 0.634 | 0.651 |
| E1SUM | 0.695 | 0.738 | 0.708 |
| DRS | 0.542 | 0.672 | 0.583* |
| Correlation coefficients | |||
| (GDS-5, GDS-15) | 0.858 | 0.852 | 0.856 |
| (DRS, GDS-15) | 0.073 | 0.098 | 0.080 |
| (DRS, GDS-5) | 0.065 | 0.064 | 0.062 |
| (E1SUM, GDS-15) | 0.068 | 0.096 | 0.072 |
| (E1SUM, GDS-5) | 0.055 | 0.058 | 0.049 |
| (E1SUM, DRS) | 0.850 | 0.940 | 0.865* |
Abbreviations: GDS-15, 15-item Geriatric Depression Scale; GDS-5, 5-item Geriatric Depression Scale; DRS, Minimum Data Set (MDS) Depression Rating Scale; E1SUM denotes the sum of all mood and anxiety items in section E1 of the MDS; SD, standard deviation
* For each respondent, if a majority of the items were not missing, any missing item was replaced with the mean of the non-missing items.
† Missing item responses replaced with mean score for all respondents 'non-missing' on that item.