MOD20FNO2 is a 3-digit-numeric variable.
000: Not in Universe
996: Unable to do this activity
998: Unknown-not ascertained
999: Unknown-don't know
MOD20FNO2 reports the frequency, in number of units, with which sample adults engaged in light or moderate leisure-time physical activities for periods of at least 20 minutes. It must be interpreted in conjunction with the variable MOD20FTP2, which reports the time period (e.g., per day, week, month, or year) corresponding to the number of units in MOD20FNO2. For example, a respondent who walks once a day would have a MOD20FNO2 value of 1 (to indicate 1 time) and a MOD20FTP2 value of 2 (which is the IPUMS NHIS code for "day").
MOD20FWK2, a recoded variable created by the staff at the National Center for Health Statistics, draws upon the information in MOD20FTP2 and MOD20FNO2 and reports the frequency of light or moderate leisure-time physical activities for at least 20 minutes in terms of a single time unit, times per week.
Light or moderate activities are described in the survey question itself 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, MOD20FNO2 is only available for quarters 1 and 2 of 1997. At that time respondents were asked to report how frequently 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.
The NHIS Survey Description for 1997 describes this situation of changing reference periods for physical activity as follows:
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.
These transitional variables combined the data on light or moderate leisure-time physical activity for at least 20 minutes from quarters 1 and 2, with data from the subset of respondents in quarters 3 and 4 who engaged in light or moderate leisure-time physical activity for at least 20 minutes. In other words, the transitional variables for 1997 allow comparability across all quarters of 1997 only by excluding respondents from quarters 3 and 4 whose physical activity lasted between 10 and 19 minutes (i.e., less than 20 minutes in duration). Researchers who wish to analyze data on light or moderate physical activity (for 20+ minutes) for all quarters of 1997 can use these transitional variables:
- MOD20FNO (Frequency of moderate activity 20+ minutes: Number of units)
- MOD20FTP (Frequency of moderate activity 20+ minute: Time period)
- MOD20FWK (Frequency of moderate activity 20+ minutes: Times per week)
- MOD20DNO (Duration of moderate activity 20+ minutes: Number of units)
- MOD20DTP (Duration of moderate activity 20+ minutes: Time period)
- MOD20DMIN (Duration of moderate activity 20+ minutes: Minutes)
Researchers who wish to analyze data from multiple years on adults' leisure-time light or moderate 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.
- 1997 : SAMPWEIGHT