Table of Contents

Component Description

The vision section (abbreviated "VIQ" in the NHANES questionnaire variable naming convention scheme), provides personal interview data on several vision topics.

Topics and the target population groups in the VIQ section:

Eligible Sample

Please review the questionnaire and codebook carefully. Frequency counts were verified during the preparation of the file.

Interview Setting and Mode of Administration

Interview Setting:

Trained household interviewers collected all of the Sample Person interviews. In most cases, the interview setting was the Sample Person's home. The information was recorded using a format computer-assisted personal interview (CAPI) system. All household interviewers were required to complete a comprehensive two-week training program. Many of the interviewers had prior interviewing experience. A large percentage of the household interviewers were bilingual in English and Spanish.

NHANES interviewer training included role-playing exercises and practice interviews, all of which were monitored by NCHS and contractor staff. Additionally, all of the NHANES questionnaires were translated into Spanish and were accessible in CAPI format. Detailed information about the interviewer training requirements is found in the NHANES Household Interviewer Training Manual.

Examination Protocol:

Not applicable. The VIQ section was part of the Household Interview component of the survey; this component is completed prior to the mobile examination center (MEC) component.

Data Collection:

All of the responses to the questionnaire items were recorded using the NHANES CAPI interview system. Some of the questions in the VIQ section required the use of printed hand cards. When necessary, the household interviewers read the hand card selections to the respondent.

Quality Assurance & Quality Control

Several types of quality control were implemented to ensure that high quality data were collected during the survey.

Interviewer monitoring was a major responsibility for NCHS and contractor staff. Interviewers were frequently accompanied on interviews and observed to verify that the interview protocol was administered correctly. Interviewers were retrained on survey procedures if necessary.

Extensive pretesting was completed prior to implementing the questionnaires in the field. A full "dress rehearsal" pilot test was conducted with the field and examination staff to test all of the survey participant contact, interview, and examination procedures.

The interviewers are encouraged to provide comments and other suggestions, based on their field experiences. NCHS has used field staff and interviewer feedback to improve the questionnaires and survey materials. Annual staff debriefing and training sessions are conducted jointly by NCHS and contractor staff. Interviewers are trained on new survey content and protocol changes prior to implementation in the field.

With respect to data collection quality control, the CAPI systems have built-in edit and range checks for most questions that have open-ended response options. When unusual or unrealistic responses were recorded, the interviewer is alerted immediately and instructed to verify or edit the initial response.

Data Processing and Editing

Frequency counts were checked, "skip" patterns were verified, and the reasonableness of responses to the questions was reviewed.

There were no edits made to the responses to the questions.

Analytic Notes

The analysis of NHANES 1999–2000 vision data must be conducted with the key survey design and basic demographic variables. The NHANES 1999–2000 Household Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interviews. They also contain all survey design variables and sample weights for these age groups. Other household questionnaire and vision examination files may be linked to the vision questionnaire data file using the unique survey participant identifier SEQN.

Please refer to the NCHS analytic guidelines to determine the appropriate analytic plan for this dataset.

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 50 YEARS - 150 YEARS

VIQ030 - General condition of eyesight

Variable Name:
VIQ030
SAS Label:
General condition of eyesight
English Text:
Next I have general questions about {your/SP's} vision. At the present time, would you say {your/SP's} eyesight, with glasses or contact lenses if {you/s/he} wear them, is . . .
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Excellent, 481 481
2 Good, 1101 1582
3 Fair, 559 2141
4 Poor, or 166 2307
5 Very poor? 67 2374
7 Refused 3 2377
9 Don't know 4 2381
. Missing 39 2420

VIQ040 - Time worrying about eyesight

Variable Name:
VIQ040
SAS Label:
Time worrying about eyesight
English Text:
How much of the time {do you/does SP} worry about {your/his/her} eyesight? Would you say . . .
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 None of the time, 1298 1298
1 A little of the time, 477 1775
2 Some of the time, 380 2155
3 Most of the time, or 135 2290
4 All of the time? 119 2409
7 Refused 3 2412
9 Don't know 6 2418
. Missing 2 2420

VIQ050A - Difficulty reading ordinary newsprint

Variable Name:
VIQ050A
SAS Label:
Difficulty reading ordinary newsprint
English Text:
The next questions are about how much difficulty, if any, {you have/SP has} doing certain activities, such as reading ordinary newsprint or going down steps. If {you/s/he} usually wear{s} glasses or contact lenses to do these activities, please rate {you r/his/her} ability to do them while wearing {your/his/her} glasses or contacts. How much difficulty {do you/does SP} have . . .reading ordinary print in newspapers?
English Instructions:
HAND CARD VIQ1. READ CATEGORIES TO RESPONDENT IF NECESSARY.
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1662 1662
2 A little difficulty 378 2040
3 Moderate difficulty 144 2184
4 Extreme difficulty 81 2265
5 Unable to do because of eyesight 82 2347
6 Does not do this for other reasons 67 2414
77 Refused 3 2417
99 Don't know 1 2418
. Missing 2 2420

VIQ050B - Difficulty with up close work or chores

Variable Name:
VIQ050B
SAS Label:
Difficulty with up close work or chores
English Text:
How much difficulty {do you/does SP} have . . .doing work or hobbies that require {you/him/her} to see well up close such as cooking, sewing, fixing things around the house, or using hand tools?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1786 1786
2 A little difficulty 319 2105
3 Moderate difficulty 127 2232
4 Extreme difficulty 73 2305
5 Unable to do because of eyesight 52 2357
6 Does not do this for other reasons 57 2414
77 Refused 3 2417
99 Don't know 1 2418
. Missing 2 2420

VIQ050C - Difficulty seeing steps/curbs-dim light

Variable Name:
VIQ050C
SAS Label:
Difficulty seeing steps/curbs-dim light
English Text:
How much difficulty {do you/does SP} have . . .going down steps, stairs, or curbs in dim light or at night?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1670 1670
2 A little difficulty 353 2023
3 Moderate difficulty 141 2164
4 Extreme difficulty 94 2258
5 Unable to do because of eyesight 50 2308
6 Does not do this for other reasons 101 2409
77 Refused 3 2412
99 Don't know 6 2418
. Missing 2 2420

VIQ050D - Difficulty noticing objects to side

Variable Name:
VIQ050D
SAS Label:
Difficulty noticing objects to side
English Text:
How much difficulty {do you/does SP} have . . .noticing objects off to the side while {you are/s/he is} walking?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1956 1956
2 A little difficulty 243 2199
3 Moderate difficulty 82 2281
4 Extreme difficulty 58 2339
5 Unable to do because of eyesight 33 2372
6 Does not do this for other reasons 34 2406
77 Refused 3 2409
99 Don't know 9 2418
. Missing 2 2420

VIQ050E - Difficulty findng object on crowdedshelf

Variable Name:
VIQ050E
SAS Label:
Difficulty findng object on crowdedshelf
English Text:
How much difficulty {do you/does SP} have . . .finding something on a crowded shelf?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1926 1926
2 A little difficulty 252 2178
3 Moderate difficulty 97 2275
4 Extreme difficulty 61 2336
5 Unable to do because of eyesight 41 2377
6 Does not do this for other reasons 32 2409
77 Refused 3 2412
99 Don't know 6 2418
. Missing 2 2420

VIQ055 - Difficulty drivng daytime-familiar place

Variable Name:
VIQ055
SAS Label:
Difficulty drivng daytime-familiar place
English Text:
How much difficulty {do you/does SP} you have driving during the daytime in familiar places?
English Instructions:
HAND CARD VIQ2
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 No difficulty 1691 1691
2 A little difficulty 66 1757
3 Moderate difficulty 19 1776
4 Extreme difficulty 5 1781
5 Unable to do because of eyesight 76 1857
6 Does not do this for other reasons 238 2095
7 Never drove 319 2414
77 Refused 3 2417
99 Don't know 1 2418
. Missing 2 2420

VIQ060 - Vision limits how long can do activities

Variable Name:
VIQ060
SAS Label:
Vision limits how long can do activities
English Text:
How limited {are you/is SP} in how long {you/s/he} can work or do other daily activities such as housework, child care, school, or community activities because of {your/his/her} vision? Would you say {you are/s/he is} limited . . .
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 None of the time, 1862 1862
1 A little of the time, 250 2112
2 Some of the time, 135 2247
3 Most of the time, or 70 2317
4 All of the time? 94 2411
7 Refused 3 2414
9 Don't know 4 2418
. Missing 2 2420

VIQ070 - Ever had a cataract operation

Variable Name:
VIQ070
SAS Label:
Ever had a cataract operation
English Text:
{Have you/Has SP} ever had a cataract operation?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 460 460
2 No 1950 2410
7 Refused 3 2413
9 Don't know 5 2418
. Missing 2 2420

VIQ080 - Operation in right, left or both eyes

Variable Name:
VIQ080
SAS Label:
Operation in right, left or both eyes
English Text:
Was the operation in {your/SPs} right eye, left eye, or both eyes?
Target:
Both males and females 50 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Right eye 78 78
2 Left eye 71 149
3 Both 308 457
7 Refused 0 457
9 Don't know 3 460
. Missing 1960 2420