Retest reliability of visual function questionnaire items, hospital 2
| Questionnaire visual function items | Hospital 2, group 1 | Hospital 2, group 2 | |||||
|---|---|---|---|---|---|---|---|
| Number | Spearman correlation | Kappa coefficient | Number | Spearman correlation | Kappa coefficient | ||
| Rating of vision | 8 | 0.89 | 0.80 | 15 | 0.77 | NA | |
| Vision hinders usual activity | 8 | 0.93 | 0.80 | 14 | 0.66 | NA | |
| Vision hinders recognising people | 8 | 0.95 | NA | 15 | 0.75 | 0.23 | |
| Vision hinders reading price labels | 8 | 0.93 | NA | 15 | 0.66 | 0.27 | |
| Vision hinders reading magazine | 8 | 0.93 | NA | 15 | 0.75 | NA | |
| Vision hinders knitting | 9 | 0.74 | NA | 15 | 0.76 | NA | |
| Vision hinders watching TV | 7 | 0.76 | NA | 15 | 0.56 | NA | |
| Vision hinders daytime driving | 9 | 0.99 | NA | 15 | 0.7 | NA | |
| Vision hinders night-time driving | 9 | 0.97 | 0.84 | 15 | 0.76 | NA | |
| Glare hinders usual activities | 9 | 0.82 | NA | 15 | 0.68 | 0.23 | |
| Glare hinders reading shiny paper | 9 | 0.90 | NA | 15 | 0.70 | NA | |
| Glare hinders driving towards the sun | 9 | 0.97 | NA | 15 | 0.76 | NA | |
| Glare hinders walking outside on a sunny day | 9 | 0.93 | NA | 15 | 0.83 | 0.33 | |
| Overall average | 8.5 | 0.90 | 0.81 | 14.9 | 0.72 | 0.27 | |
↵Group 1 patients: those for whom the person(s) who responded in the retest was/were the same as in the test (see text).
↵Group 2 patients: those for whom the person(s) who responded in the retest was/were not the same as in the test (see text).
NA = kappa coefficient could not be calculated because of unequal categories between the test and retest results for this data item owing to small numbers.