Table 1.
National Eye Institute Visual Function Questionnaire 25 – items and subscales
| No. | Item | Subscale | Response categories (n) | Missing data (%) | Floor effect (%) | Ceiling effect (%) |
|---|---|---|---|---|---|---|
| 1 | General health | General health | Quality (6) | 2.2 (5/233) | 17.1 (39/228) | 7.0 (16/228) |
| 2 | General vision | General vision | Quality (6) | 1.3 (3/233) | 0.4 (1/230) | 7.7 (18/230) |
| 3 | Worry about eyesight | Mental health | Frequency (5) | 0.9 (2/233) | 2.6 (6/231) | 20.8 (48/231) |
| 4 | Pain around eyes | Ocular pain | Quality (5) | 0.9 (2/233) | 0 (0/231) | 28.9 (136/231) |
| 5 | Reading normal print | Near vision | Difficulty (5) | 2.6 (6/233)a | 8.8 (20/227) | 33.0 (75/227) |
| 6 | Seeing well up close | Near vision | Difficulty (5) | 8.6 (20/233)a | 8.9 (19/213) | 28.6 (61/213) |
| 7 | Finding objects on crowded shelf | Near vision | Difficulty (5) | 5.6 (13/233)a | 2.7 (6/220) | 45.0 (99/220) |
| 8 | Reading street signs | Distance vision | Difficulty (5) | 5.6 (13/233)a | 5.0 (11/220) | 50.5 (111(220) |
| 9 | Going down stairs at night | Distance vision | Difficulty (5) | 10.3 (24/233)a | 4.3 (9/209) | 23.0 (48/209) |
| 10 | Seeing objects off to side | Peripheral vision | Difficulty (5) | 3.4 (8/233)a | 1.8 (4/225) | 38.2 (86/225) |
| 11 | Seeing how people react | Social function | Difficulty (5) | 4.7 (11/233)a | 2.3 (5/222) | 55.0 (122/222) |
| 12 | Difficulty matching clothes | Colour vision | Difficulty (5) | 8.2 (19/233)a | 2.8 (6/214) | 65.0 (139/214) |
| 13 | Visiting others | Social function | Difficulty (5) | 12.0 (28/233)a | 4.4 (9/205) | 55.6 (114/205) |
| 14 | Going out to movies/plays | Distance vision | Difficulty (5) | 29.6 (69/233)a | 12.2 (20/164) | 48.8 (80/164) |
| 15 | Driving in daylight | Driving | Difficulty (5) | 77.3 (180/233) | 0 (0/53) | 90.6 (48/53) |
| 16 | Driving in difficult conditions | Driving | Difficulty (5) | 79.4 (185/233)a | 10.4 (5/48) | 14.6 (7/48) |
| 17 | Accomplish less | Role limitations | Frequency (5) | 3.0 (7/233) | 12.0 (27/226) | 45.1 (102/226) |
| 18 | Limited endurance | Role limitations | Frequency (5) | 4.3 (10/233) | 9.9 (22/223) | 41.7 (93/223) |
| 19 | Amount of time in pain | Ocular pain | Frequency (5) | 4.3 (10/233) | 0.5 (1/223) | 64.6 (144/223) |
| 20 | Stay home most of the time | Dependency | Agreement (5) | 3.0 (7/233) | 5.3 (12/226) | 73.9 (167/226) |
| 21 | Frustrated | Mental health | Agreement (5) | 2.6 (6/233) | 7.1 (16/227) | 64.3 (146/227) |
| 22 | No control | Mental health | Agreement (5) | 2.6 (6/233) | 8.8 (20/227) | 59.0 (134/227) |
| 23 | Rely too much on others’ words | Dependency | Agreement (5) | 2.6 (6/233) | 7.5 (17/227) | 70.9 (161/227) |
| 24 | Need much help from others | Dependency | Agreement (5) | 2.6 (6/233) | 8.8 (20/227) | 70.5 (160/227) |
| 25 | Embarrassment | Mental health | Agreement (5) | 3.0 (7/233) | 2.2 (5/226) | 76.1 (172/227) |
Items in gray indicate excluded before Rasch analysis.
a
A sixth option (stopped doing for other reasons/not interested in doing) was considered as missing data.