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

All survey participants 20 years and older were eligible for the initial question (VIQ010), the ability to see light. Participants 50 years and older were asked further detailed questions about their vision (refer above).

Interview Setting and Mode of Administration

A trained household interviewer administrated these questions to the survey participant during the household interview. The information was recorded using a computer-assisted personal interview (CAPI) 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.

The computer CAPI system had built-in consistency checks, online information screens that provided the interviewers with information about the terms used in the questionnaires, and hard and soft edit checks to reduce the number of keying entry errors. All of the interviews were reviewed by the NHANES field office staff for accuracy and completeness.

Additional details describing the quality assurance/quality control processes are provided in the survey procedures manuals.

Data Processing and Editing

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

The variable VIQ031 contains 31 additional missing values than subsequent variables. This is due to a question (VIQ015/VIQ016) that was asked of participants prior to VIQ031 but is not included in this 2003-2004 data release file due to quality control reasons. Participants who responded "no" to the VIQ015/VIQ016 question were skipped to question VIQ041 and were not asked question VIQ031.

Analytic Notes

The 2003-2004 vision questions asked of participants 50 years and older are similar to the 1999-2000 and 2001-2002 vision questions. In addition to the vision questionnaire data, vision examination data can be found in the vision section of the NHANES 2003-2004 Exam Files (VIX). These two datasets can be combined using the unique survey participant identifier (SEQN) and analyzed using the guidelines provided by NCHS.

Although these data were collected as part of the household questionnaire, if they are merged with the MEC exam data, exam sample weights should be used for the analyses.

Please refer to the Analytic Guidelines for further details on the use of sample weights and other analytic issues at https://wwwn.cdc.gov/nchs/nhanes/analyticguidelines.aspx.

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 20 YEARS - 150 YEARS

VIQ010 - Can see light

Variable Name:
VIQ010
SAS Label:
Can see light
English Text:
Next I have general questions about (your/SP's) vision. With both eyes open, can (you/he/she) see light?
Target:
Both males and females 20 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 5030 5030
2 No 9 5039 VIQ071
7 Refused 0 5039
9 Don't know 0 5039
. Missing 2 5041

VIQ031 - General condition of eyesight

Variable Name:
VIQ031
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, 667 667
2 Good, 1164 1831
3 Fair, 494 2325
4 Poor, or 108 2433
5 Very poor? 28 2461
7 Refused 0 2461
9 Don't know 12 2473
. Missing 2568 5041

VIQ041 - Time worrying about eyesight

Variable Name:
VIQ041
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, 1409 1409
1 A little of the time, 464 1873
2 Some of the time, 368 2241
3 Most of the time, or 137 2378
4 All of the time? 110 2488
7 Refused 0 2488
9 Don't know 16 2504
. Missing 2537 5041

VIQ051A - Difficulty reading ordinary newsprint

Variable Name:
VIQ051A
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 1811 1811
2 A little difficulty 367 2178
3 Moderate difficulty 142 2320
4 Extreme difficulty 64 2384
5 Unable to do because of eyesight 53 2437
6 Does not do this for other reasons 54 2491
77 Refused 0 2491
99 Don't know 13 2504
. Missing 2537 5041

VIQ051B - Difficulty with up close work or chores

Variable Name:
VIQ051B
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 1877 1877
2 A little difficulty 358 2235
3 Moderate difficulty 118 2353
4 Extreme difficulty 49 2402
5 Unable to do because of eyesight 40 2442
6 Does not do this for other reasons 50 2492
77 Refused 0 2492
99 Don't know 12 2504
. Missing 2537 5041

VIQ051C - Difficulty seeing steps/curbs-dim light

Variable Name:
VIQ051C
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 1740 1740
2 A little difficulty 356 2096
3 Moderate difficulty 150 2246
4 Extreme difficulty 99 2345
5 Unable to do because of eyesight 35 2380
6 Does not do this for other reasons 111 2491
77 Refused 0 2491
99 Don't know 13 2504
. Missing 2537 5041

VIQ051D - Difficulty noticing objects to side

Variable Name:
VIQ051D
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 2109 2109
2 A little difficulty 184 2293
3 Moderate difficulty 97 2390
4 Extreme difficulty 42 2432
5 Unable to do because of eyesight 24 2456
6 Does not do this for other reasons 27 2483
77 Refused 0 2483
99 Don't know 21 2504
. Missing 2537 5041

VIQ051E - Difficulty findng object on crowdedshelf

Variable Name:
VIQ051E
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 2057 2057
2 A little difficulty 255 2312
3 Moderate difficulty 84 2396
4 Extreme difficulty 42 2438
5 Unable to do because of eyesight 23 2461
6 Does not do this for other reasons 29 2490
77 Refused 0 2490
99 Don't know 14 2504
. Missing 2537 5041

VIQ056 - Difficulty drivng daytime-familiar place

Variable Name:
VIQ056
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 1861 1861
2 A little difficulty 55 1916
3 Moderate difficulty 10 1926
4 Extreme difficulty 7 1933
5 Unable to do because of eyesight 59 1992
6 Does not do this for other reasons 260 2252
7 Never drove 240 2492
77 Refused 0 2492
99 Don't know 12 2504
. Missing 2537 5041

VIQ061 - Vision limits how long can do activities

Variable Name:
VIQ061
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, 2001 2001
1 A little of the time, 247 2248
2 Some of the time, 139 2387
3 Most of the time, or 48 2435
4 All of the time? 57 2492
7 Refused 0 2492
9 Don't know 12 2504
. Missing 2537 5041

VIQ071 - Ever had a cataract operation

Variable Name:
VIQ071
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 552 552
2 No 1957 2509 End of Section
7 Refused 0 2509 End of Section
9 Don't know 0 2509 End of Section
. Missing 2532 5041

VIQ081 - Operation in right, left or both eyes

Variable Name:
VIQ081
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 95 95
2 Left eye 66 161
3 Both 386 547
7 Refused 0 547
9 Don't know 5 552
. Missing 4489 5041