Concept: Physical Activity During Leisure Time - Measuring Prevalence
Last Updated: 2015-05-29
In the MHHS respondents were asked, "Do you regularly engage in physical exercise during your leisure time? By regularly we mean at least once a week during the past two months." Those who did not answer "no" were then asked, "How many times per week do you exercise at least 15 minutes?"
Responses were grouped as:
- "active" - includes daily, 5–6 times per week, 3–4 times per week,
- "moderate" - 1–2 times per week, and
- "inactive" - less than once per week and never. Those who answered "no" to the previous question were assigned to the "inactive" category.
Using the CCHS and NPHS
In the CCHS and NPHS, the leisure time physical activity index is a derived variable for survey respondents based on their average daily energy expenditure values (kcal/kg/day), calculated from a series of questions on physical activity. It includes physical activity for a variety of activities such as walking, running, gardening, soccer, etc., by the participant in the past three months. Respondents were asked questions such as, "In the past 3 months, how many times did you walk for exercise? About how much time did you spend on each occasion?"
Based on their answers, respondents' intensity of physical activity and total time spent active was converted into their average daily energy expenditure - a term called metabolic equivalent values or METs. Respondents were then grouped into three categories based on this value:
- "active" - three or more METs
- "moderate" - 1.5 to less than three METs, or
- "inactive" - zero to less than 1.5 METs.
Calculating the Prevalence of Physical Activity During Leisure Time
The weighted crude prevalence rates of the three levels of physical activity during leisure time were then calculated for survey respondents aged 12 and older. Respondents who answered "don't know" and those with missing or invalid data were excluded from the prevalence calculation.