MOD20DNO2 is a 3-digit-numeric variable.
000: Not in Universe
998: Unknown-not ascertained
999: Unknown-don't know
MOD20DNO2 reports the duration, in number of units, of sample adults' light or moderate leisure-time physical activities that lasted at least 20 minutes. This variable must be interpreted in conjunction with the variable MOD20DTP2, which reports the time period (minutes or hours) corresponding to the number of units reported in MOD20DNO2. For example, a respondent who walks for 30 minutes would have a MOD20DNO2 value of 30 and a MOD20DTP2 value of 1 (which is the IPUMS NHIS code for "minutes").
MOD20DMIN2, a recoded variable created by the staff at the National Center for Health Statistics, draws upon the information in MOD20DNO2 and MOD20DTP2 and reports the duration of light or moderate physical activity (for at least 20 minutes) in a standardized unit of time, minutes.
Light or moderate activities are described in the survey questionnaire as activities that "cause only light sweating or a slight to moderate increase in breathing or heart rate." The Field Representative's Manuals for 1997 forward provide examples of light or moderate leisure-time physical activities, although these examples were not routinely shared with respondents. These examples include leisurely walking or bicycling, slow swimming or dancing, and simple gardening.
Due to an error in the wording of the survey question, MOD20DNO2 is only available for quarters 1 and 2 of 1997. At that time respondents were asked to report how long they engaged in physical activities lasting a minimum of 20 minutes. This mistake was corrected beginning in quarter 3 of 1997, when the minimum duration of physical activity was lowered to 10 minutes.
To allow analysis of light or moderate leisure-time physical activity across all quarters of 1997, the National Center for Health Statistics created "transitional" variables for 1997 only, covering respondents who did light or moderate exercise for at least 20 minutes.
See MOD20FNO2 for a list and discussion of these transitional variables on light or moderate physical activity for at least 20 minutes. which are available for 1997 only.
Researchers who wish to analyze data from multiple years on adults' light or moderate leisure-time physical activity should restrict their data from 1997 to quarters 3 and 4 and use variables beginning with "MOD10."
See VIG10FNO for an overview of the variables relating to adults' leisure-time physical activity for at least 10 minutes for the third quarter of 1997 forward.
- 1997: Sample adults age 18+ in quarters 1 and 2 who participate in moderate activities at least 20 minutes.
- 1997 : SAMPWEIGHT