Concept: Physical Activity During Leisure Time - Measuring Prevalence

Introduction

This concept provides information on developing a prevalence measure of "physical activity during leisure time" that can be derived from survey data. Information for this concept is from The Cost of Smoking: A Manitoba Study deliverable by Martens et al. (2015). The concept identifies the data sources for this information, describes how the measure is developed from this data, and provides links to MCHP research that uses this measure.

Data Sources

Data that can be used to calculate a measure of physical activity during leisure time is available from three different sources:


• the Canadian Community Health Survey (CCHS),
  
• the National Population Health Survey (NPHS), and
  
• the Manitoba Heart Health Survey (MHHS).

Developing A Measure of Physical Activity During Leisure Time

Questions about physical activity during leisure time were asked in all the survey waves except for the CCHS - Healthy Aging Survey. In our definition, leisure time does not include physical activity performed during work as part of an occupation, or during school, or for travel. Different methods were used, depending on the survey, to arrive at common categories for measuring physical activity using all the available survey data. These methods are described below.

Using the MHHS

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.

MCHP Research Into Physical Activity - Leisure

In The Cost of Smoking: A Manitoba Study deliverable by Martens et al. (2015) they calculated prevalence rates for the three different levels of physical activity during leisure time for survey respondents aged 12 and older. The prevalence rates found in this research are available in the following tables:


• Table 4.3: Basic Descriptive Statistics of the Estimated-Population-Based Sample* by Ever Smoked and Never Smoked Categories
  
• Table 4.7: Basic Descriptive Statistics of the Estimated-Population-Based Sample* by Smoking Status Categories