Leisure time physical activity in Scotland: trends 1987-1991 and the effect of question wording

In this article data collected between 1987 and 1991 is analyzed to identify changes in the proportion of sedentary individuals in Edinburgh and Glasgow. In the primary question, which asked the respondents about physical activity for exercise such as walking, running and swimming, a wording change deleting the prompt to specific activities is taken into consideration. The data were collected by telephone on 13,586 respondents. A considerable decrease in the proportion of sedentary individuals in both cities was observed between 1987 and 1991. This decrease could not be related to changes in specific sporting activities. The change to an unprompted question led to a 14% lower estimate of physical activity. This was almost fully explained by a change in the estimate of the proportion of walkers. Older respondents in particular were affected by the question change.