# Presentation: 676489

## Question on visionResults of the cognitive test

**Jeremiah Banda and Maria Martinho**
**United Nations Statistics Division**

## Analysis of cognitive data

**The cognitive test included:**
**The WG question **
**     ***Do you have difficulty seeing even if wearing glasses?*
**Other questions on vision and seeing difficulties**
**     ***Without/With your glasses, how often do you have difficulty seeing well?*
*     ...*
*     **Without/With your glasses, do you have difficulty seeing and recognizing a person from 7 meters (20 feet) away?*
**A question on the use of glasses**
**    ***Do you wear glasses all of the time, only for certain activities or none of the time?*

## Analysis of cognitive data (cont.)

**Response patterns**
**Aim:**** compare replies to WG question with those to other questions**
**Interpretation of results**
**Purposive sample: % of cases in each pattern is not and  estimate of the % in the general population.**
**Replies to open question can suggest explanations for inconsistencies between the WG question and the other questions**
**International comparability: do respondents in different countries interpret the question in a similar way?**

| Wears glasses? | Reported seeing difficulties? |  |
| --- | --- | --- |
|  | WG question | Other questions |
| Yes/No | Yes/No | Yes/No |

## Response patterns

| Pattern | WG question | Other questions | Wears glasses |
| --- | --- | --- | --- |
| A | No | No | No |
| B | No | No  | Yes |
| C | Yes | Yes | No |
| D | Yes | Yes  | Yes |
| E | Yes | No  | Yes |
| F | Yes | No | No |
| G | No | Yes  | Yes |
| H | No | Yes | No |

## Response patterns

**WG question and near/far vision questions**
*Do you have difficulty *
**Near vision: ***seeing the print in a map, newspaper or book?*
**Far vision: ***seeing/recognizing a person you know from 7 meters away?*

|   | A | B | C | D | E | F | G | H | Total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Gambia | 70 | 0 | 5 | 7 | 1 | 0 | 0 | 0 | 83 |
| Philippines | 5 | 1 | 4 | 6 | 6 | 1 | 0 | 1 | 24 |
| Paraguay | 35 | 14 | 17 | 9 | 17 | 6 | 2 | 4 | 104 |
| ... |  |  |  |  |  |  |  |  |  |
|  Total | 388 | 122 | 154 | 159 | 120 | 26 | 19 | 26 | 1014 |

**Inconsistency between the WG and near/far vision questions**

**Notes:**
There are incon

## Response patterns

**WG question, near/far vision and diff/effort questions**
*Without/ With your glasses,  *
**Diff: ***how often do you have difficulty seeing well?** *
**Effort: ***seeing/recognizing a person you know from 7 meters away?*

**Inconsistency between the WG and near/far vision questions**

| A | B | C | D | E | F | G | H | Total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 388 | 122 | 178 | 209 | 70 | 2 | 19 | 26 | 1014 |

**Notes:**
There are incon

## Response patterns

**WG question, near/far vision and diff/effort questions**

|   | A | B | C | D | E | F | G | H | Total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Near/far vision  | 388 | 122 | 154 | 159 | 120 | 26 | 19 | 26 | 1014 |
| Near/far vision and diff/effort | 388 | 122 | 178 | 209 | 70 | 2 | 19 | 26 | 1014 |

**More consistent replies when the diff/effort questions are taking into account**

**Notes:**
There are incon

## Some thoughts on the glasses clause

**The difficulties and location of the glasses clause only explains a part of the discrepancies between the WG question and the near/far vision question**

**then inconsistencies between diff/effort questions and WG questions should be equally high. ****They are not!**

**Near/far vision &**
**diff/effort questions**

**WG question**

**At the beginning**
**Difficult to understand**

**At the end**
**Easier to understand**

**If the difficulties and location of the glasses clause were the only reason for inconsistencies between near/far vision and WG questions,**

**Notes:**
There are incon

## Response patterns in detail

**WG question, near/far vision and diff/effort questions**

|  | Replies to WG Question |  |  |  |
| --- | --- | --- | --- | --- |
| Highest reply among other vision questions | 0 | 1 | 2 | 3 |
| 0 | 510 | 30 | 9 | 6 |
| 1 | 67 | 144 | 74 | 16 |
| 2 | 5 | 23 | 49 | 29 |
| 3 | 0 | 0 | 1 | 51 |
|  |  |  |  | 
 |
| N=1014 |  |  |  |  |

**0 = No difficulty/Never**

**Notes:**
There are incon

## Inconsistent respondents: Replies to the open question

**WG question, near/far vision and diff/effort questions**

**Pattern E ****- wears glasses, yes to WG question**
**Glasses clause misunderstood in WG question: 33 respondents      (e.g. “*****because I wear glasses*****”, “*****I am short-sighted*****”)**
**Near/far vision questions not able to capture respondent’s seeing problems: 11 respondents (e.g. cataracts, problem with one eye only)**
**No clear explanation: 26 respondents**** **

**Pattern F ****- no glasses, yes to WG question**
**2 respondents (both from Vietnam) reported **_**some difficulty**_** in the WG question: **
**because they can see well!!!**** **

**Notes:**
There are incon

## Inconsistent respondents: Replies to the open question

**WG question, near/far vision and diff/effort questions**

**Pattern G ****- wears glasses, no to WG question**
**15 respondents understood the glasses clause and reported no difficulty to WG question (e.g. “*****I see well with glasses*****”). Why do they report difficulties to the near/far vision?)**
**No clear explanation: 4 respondents**** **

**Pattern H ****- no glasses, no to WG question**
**11 respondents claim to see well (why do they report difficulties to the near/far question?)**
**1 does not report difficulties to WG question because he is not blind**
**2 wear glasses!!! (we can not use near/far question)**
**No clear explanation: 12 respondents**

**Notes:**
There are incon

## Comparability of the WG question across countries

**Interpretations found in several countries:**
**Glasses clause **_**missed**_** in the WG question: Kenya, Egypt, Vietnam, Argentina, Paraguay, Brazil, Mexico**
**Glasses clause **_**understood**_** in the WG question: Argentina, Paraguay, Brazil and Mexico**
**Inconsistency between WG and near/far questions for persons with problem in one eye only, cataracts, irregular blurred vision: Paraguay, Argentina, Brazil, Philippines**
**All replies consistent: all countries**

**Notes:**
There are incon

## Comparability of the WG question across countries

**Interpretations found in several countries (cont.):**
**Respondents claim to see well with glasses but report difficulties in the near/far question: Argentina, India, Paraguay, Brazil and Mexico**
**Respondents do not wear glasses, claim to see well but report difficulties in the near/far question: Uganda, Kenya, Argentina, India, Philippines, Paraguay, Brazil and Mexico**
**Country-specific interpretations:**
**Report some difficulty in seeing because they see well (Vietnam)**

**Notes:**
There are incon

## Conclusions and issues to discuss

**‘****Even if wearing glasses’: in or out?**
**Sometimes respondents (or interviewers?) miss it**
**WG question interpreted in a comparable way across countries?**
**Most response patterns and interpretations were found in several countries**
**Inconsistencies between WG questions and near/far vision were often due to:**
**The glasses clause can be missed in any of those questions**
**Some disabilities not captured by the near/far vision question (such as blind of one eye)**

**Notes:**
There are incon

## Conclusions and issues to discuss

**Other explanations suggested for inconsistencies:**
**A respondent that needs glasses may reply to the WG question in a hypothetical way (*****If I had glasses, I would see well*****)**
**Some persons anticipate financial assistance by reporting a difficulty**
**Ageing respondents may believe their vision is weakening**
**Blind people do not report difficulties in near/far vision questions**
**Illiterate people report difficulties in near vision question**
**Only field tests can tell us if the % of people falling in the inconsistent patterns is large enough to be worrying**

**Notes:**
There are incon

## Further analyses

**Analyse the effect of interview difficulties**
**Study patterns of other questions on vision issues**
**Study open questions in relation with other questions**
**Repeat analysis for proxy data**
**Investigate association with socio-economic variables**

**Notes:**
There are incon