Background
Methods
The Catquest-9SF questionnaire and the translation
Participants
Rasch analysis
Results
Participant characteristics
Malay version (n = 236) | Chinese version (n = 202) | |||
---|---|---|---|---|
n | (%) | n | (%) | |
Age (years): | ||||
Mean (SD) | 63 (10.1) | 68 (9.0) | ||
Minimum, maximum | 21, 84 | 29, 86 | ||
Gender: | ||||
Male | 107 | (45.3) | 93 | (46.0) |
Female | 129 | (54.7) | 109 | (54.0) |
Race: | ||||
Malay | 179 | (75.8) | 0 | (0.0) |
Chinese | 2 | (0.8) | 202 | (100.0) |
Indian | 31 | (13.1) | 0 | (0.0) |
Others | 24 | (10.2) | 0 | (0.0) |
Education level: | ||||
No formal education | 49 | (20.8) | 51 | (25.2) |
Primary | 88 | (37.3) | 101 | (50.0) |
Secondary | 82 | (34.7) | 44 | (21.8) |
Higher education | 15 | (6.4) | 5 | (2.5) |
Best corrected visual acuity: | ||||
6/6–6/15 | 76 | (32.2) | 79 | (39.1) |
6/18–3/60 | 104 | (44.1) | 92 | (45.5) |
2/60 – NPL | 4 | (1.7) | 4 | (2.0) |
Ocular comorbiditya | 63 | (26.7) | 74 | (36.6) |
Systemic comorbidityb | 180 | (76.3) | 137 | (67.8) |
Answering questionnaire: | ||||
Self-administered | 77 | (32.6) | 62 | (30.7) |
Assistant administered | 157 | (66.5) | 139 | (68.8) |
Item | Malay version (n = 236) | Chinese version (n = 202) | ||
---|---|---|---|---|
n | (%) | n | (%) | |
a1. Do you experience that your present vision gives you difficulties in any way in your daily life? | ||||
Yes, very great difficulties | 52 | (22.0) | 19 | (9.4) |
Yes, great difficulties | 75 | (31.8) | 54 | (26.7) |
Yes, some difficulties | 82 | (34.7) | 111 | (55.0) |
No, no difficulties | 26 | (11.0) | 17 | (8.4) |
Cannot decide | 1 | (0.4) | 1 | (0.5) |
a2. Are you satisfied or dissatisfied with your present vision? | ||||
Very dissatisfied | 63 | (26.7) | 58 | (28.9) |
Rather dissatisfied | 95 | (40.3) | 95 | (47.3) |
Fairly satisfied | 61 | (25.8) | 38 | (18.9) |
Very satisfied | 17 | (7.2) | 7 | (3.5) |
Cannot decide | 0 | (0.0) | 3 | (1.5) |
Do you have difficulty with the following activities because of your vision? | ||||
1 Reading text in the newspaper | ||||
Yes, very great difficulties | 77 | (32.6) | 42 | (20.8) |
Yes, great difficulties | 56 | (23.7) | 56 | (27.7) |
Yes, some difficulties | 68 | (28.8) | 82 | (40.6) |
No, no difficulties | 21 | (8.9) | 15 | (7.4) |
Cannot decide | 14 | (5.9) | 7 | (3.5) |
2 Recognizing faces of people you meet | ||||
Yes, very great difficulties | 33 | (14.0) | 20 | (9.9) |
Yes, great difficulties | 65 | (27.5) | 38 | (18.8) |
Yes, some difficulties | 76 | (32.2) | 83 | (41.1) |
No, no difficulties | 60 | (25.4) | 60 | (29.7) |
Cannot decide | 2 | (0.9) | 1 | (0.5) |
3 Seeing prices of goods when shopping | ||||
Yes, very great difficulties | 74 | (31.4) | 40 | (19.8) |
Yes, great difficulties | 56 | (23.7) | 59 | (29.2) |
Yes, some difficulties | 55 | (23.3) | 82 | (40.6) |
No, no difficulties | 44 | (18.6) | 16 | (7.9) |
Cannot decide | 7 | (3.0) | 5 | (2.5) |
4 Seeing to walk on uneven ground | ||||
Yes, very great difficulties | 48 | (20.4) | 17 | (8.4) |
Yes, great difficulties | 64 | (27.2) | 35 | (17.3) |
Yes, some difficulties | 70 | (29.8) | 104 | (51.5) |
No, no difficulties | 50 | (21.3) | 46 | (22.8) |
Cannot decide | 3 | (1.3) | 0 | (0.0) |
5 Seeing to do needlework and handicraft | ||||
Yes, very great difficulties | 55 | (23.3) | 28 | (14.0) |
Yes, great difficulties | 53 | (22.5) | 45 | (22.5) |
Yes, some difficulties | 62 | (26.3) | 88 | (44.0) |
No, no difficulties | 44 | (18.6) | 25 | (12.5) |
Cannot decide | 22 | (9.3) | 14 | (7.0) |
6 Reading text on television | ||||
Yes, very great difficulties | 56 | (23.7) | 23 | (11.4) |
Yes, great difficulties | 55 | (23.3) | 69 | (34.2) |
Yes, some difficulties | 66 | (28.0) | 74 | (36.6) |
No, no difficulties | 44 | (18.6) | 30 | (14.9) |
Cannot decide | 15 | (6.4) | 6 | (3.0) |
7 Seeing to carry out a preferred hobby | ||||
Yes, very great difficulties | 36 | (15.2) | 19 | (9.4) |
Yes, great difficulties | 58 | (24.6) | 38 | (18.8) |
Yes, some difficulties | 67 | (28.4) | 99 | (49.0) |
No, no difficulties | 66 | (28.0) | 37 | (18.3) |
Cannot decide | 9 | (3.8) | 9 | (4.5) |
Rasch analysis
Version | Parameter | Separation index | Reliability | Average infit mean square | Average outfit mean square | |
---|---|---|---|---|---|---|
Malay | 9-items | Person ability | 2.84 | 0.89 | 1.00 | 1.01 |
Item difficulty | 4.81 | 0.96 | 1.00 | 1.00 | ||
7-itemsa | Person ability | 2.59 | 0.87 | 1.00 | 0.99 | |
Item difficulty | 4.97 | 0.96 | 1.00 | 0.98 | ||
Chinese | 9-items | Person ability | 2.59 | 0.87 | 1.00 | 1.01 |
Item difficulty | 6.96 | 0.98 | 1.00 | 1.02 | ||
7-itemsa | Person ability | 2.30 | 0.84 | 1.01 | 0.98 | |
Item difficulty | 5.28 | 0.97 | 1.00 | 0.98 |
Item | Malay version | Chinese version | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Item calibrationa (SE) | Infit | Outfit | Item calibrationa (SE) | Infit | Outfit | |||||
MNSQ | ZSTD | MNSQ | ZSTD | MNSQ | ZSTD | MNSQ | ZSTD | |||
Assessment items: | ||||||||||
1. Do you experience that your present vision gives you difficulties in any way in your daily life? | −0.16 (0.11) | 0.97 | −0.3 | 0.99 | −0.1 | 0.19 (0.13) | 1.09 | 0.9 | 1.10 | 1.0 |
2. Are you satisfied or dissatisfied with your present vision? | −0.77 (0.11) | 1.26 | 2.6 | 1.51 | 4.1 | −2.05 (0.13) | 1.01 | 0.2 | 1.36 | 2.3 |
Do you have difficulty with the following activities because of your vision? | ||||||||||
1. Reading text in the newspaper | −0.81 (0.11) | 0.85 | −1.6 | 0.81 | −1.8 | −0.66 (0.13) | 1.12 | 1.2 | 1.09 | 0.9 |
2. Recognizing faces of people you meet | 0.83 (0.11) | 1.02 | 0.3 | 1.01 | 0.1 | 1.18 (0.14) | 1.13 | 1.3 | 1.12 | 1.1 |
3. Seeing prices of goods when shopping | −0.34 (0.11) | 1.09 | 0.9 | 1.04 | 0.5 | −0.67 (0.13) | 0.93 | −0.7 | 0.91 | −0.8 |
4. Seeing to walk on uneven ground | 0.34 (0.11) | 1.01 | 0.2 | 1.01 | 0.1 | 1.12 (0.14) | 1.06 | 0.6 | 0.97 | −0.2 |
5. Seeing to do needlework and handicraft | 0.03 (0.12) | 1.01 | 0.2 | 0.97 | −0.2 | 0.11 (0.14) | 0.97 | −0.2 | 0.93 | −0.6 |
6. Reading text on television | 0.07 (0.11) | 0.89 | −1.1 | 0.85 | −1.5 | −0.01 (0.13) | 0.98 | −0.1 | 0.97 | −0.3 |
7. Seeing to carry out a preferred hobby | 0.82 (0.11) | 0.86 | −1.5 | 0.80 | −2.0 | 0.79 (0.14) | 0.73 | −2.8 | 0.71 | −2.9 |
Version | Item | DIF by age | DIF by gender | DIF by VA | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Item difficulty | Diff in logits | P-valuea | Item difficulty | Diff in logits | P-valuea | Item difficulty | Diff in logits | P-valuea | |||||
≤65 years | >65 years | Male | Female | VA >6/18 | VA ≤6/18 | ||||||||
Malay | n= | 141 | 94 | 107 | 129 | 76 | 108 | ||||||
Daily-life activities in general | −0.16 | −0.20 | 0.04 | 0.866 | −0.16 | −0.16 | 0.00 | >0.995 | −0.49 | 0.01 | −0.51 | 0.043 | |
Satisfaction with vision | −0.88 | −0.66 | −0.22 | 0.341 | −0.77 | −0.77 | 0.00 | >0.995 | −0.71 | −0.87 | 0.16 | 0.515 | |
Reading newspaper | −0.77 | −0.88 | 0.11 | 0.649 | −0.98 | −0.67 | −0.31 | 0.181 | −0.77 | −0.84 | 0.17 | 0.778 | |
Recognizing faces | 0.86 | 0.78 | 0.08 | 0.724 | 0.90 | 0.77 | 0.13 | 0.561 | 1.13 | 0.55 | 0.58 | 0.029 | |
Seeing prices when shopping | −0.27 | −0.43 | 0.16 | 0.486 | −0.43 | −0.27 | −0.15 | 0.498 | −0.46 | −0.34 | −0.12 | 0.626 | |
Walk on uneven ground | 0.34 | 0.39 | −0.05 | 0.815 | 0.53 | 0.18 | 0.35 | 0.118 | 0.45 | 0.22 | 0.23 | 0.369 | |
Needlework and handicraft | 0.06 | 0.03 | 0.02 | 0.916 | 0.03 | 0.03 | 0.00 | >0.995 | 0.07 | 0.23 | −0.16 | 0.551 | |
Reading text on TV | −0.01 | 0.20 | −0.20 | 0.382 | −0.03 | 0.15 | −0.18 | 0.432 | 0.11 | 0.21 | −0.10 | 0.685 | |
Hobbies | 0.85 | 0.78 | 0.07 | 0.772 | 0.87 | 0.78 | 0.08 | 0.712 | 0.72 | 0.82 | −0.10 | 0.717 | |
Chinese | n= | 70 | 131 | 93 | 109 | 79 | 96 | ||||||
Daily-life activities in general | −0.01 | 0.28 | −0.29 | 0.299 | 0.36 | 0.04 | 0.32 | 0.230 | −0.03 | 0.24 | −0.26 | 0.360 | |
Satisfaction with vision | −2.19 | −1.98 | −0.21 | 0.465 | −2.16 | −1.95 | −0.21 | 0.443 | −2.12 | −2.05 | −0.07 | 0.809 | |
Reading newspaper | −0.73 | −0.64 | −0.09 | 0.748 | −0.54 | −0.77 | 0.23 | 0.377 | −0.66 | −0.61 | −0.05 | 0.856 | |
Recognizing faces | 1.30 | 1.13 | 0.17 | 0.568 | 0.92 | 1.40 | −0.48 | 0.086 | 1.44 | 1.02 | 0.42 | 0.163 | |
Seeing prices when shopping | −0.71 | −0.67 | −0.04 | 0.895 | −0.79 | −0.56 | −0.23 | 0.384 | −0.57 | −0.67 | 0.10 | 0.724 | |
Walk on uneven ground | 1.12 | 1.12 | 0.00 | >0.995 | 1.17 | 1.09 | 0.08 | 0.760 | 0.98 | 1.21 | −0.23 | 0.439 | |
Needlework and handicraft | 0.14 | 0.11 | 0.03 | 0.927 | 0.25 | −0.01 | 0.26 | 0.345 | 0.04 | 0.28 | −0.24 | 0.419 | |
Reading text on TV | 0.21 | −0.12 | 0.32 | 0.259 | −0.01 | −0.01 | 0.00 | >0.995 | 0.17 | −0.13 | 0.30 | 0.300 | |
Hobbies | 0.89 | 0.75 | 0.14 | 0.635 | 0.81 | 0.79 | 0.02 | 0.942 | 0.79 | 0.71 | 0.08 | 0.793 |