Changes in sleep duration and recreational screen time among Canadians, 1998-2010.

It is commonly claimed that sleep duration has declined in recent years - over a period coinciding with a marked increase in personal electronics and communications use. The aim of this study was to assess change in sleep duration among Canadians from 1998 to 2010, and examine any associations with non-work-related screen time. The analysis uses population-representative data from Statistics Canada's General Social Survey cycles of 1998 and 2010; the respective samples numbered 10 749 and 15 390 individuals. Response rates were 80% in 1998 and 55% in 2010. Respondents were aged 15 years and older, residing in private households in the 10 Canadian provinces. The General Social Survey is administered by computer-assisted telephone interviewing. Data on sleep duration (excluding naps outside essential sleep time) and recreational screen time were obtained using a 24-h time-use diary. Survey weights were applied to adjust for non-response and non-landline households. Frequencies (respondent characteristics) and averages (time-use variables) were estimated by age group and sex. Sleep duration was examined by weighted quartile of screen time. Confidence intervals (95%) were calculated around estimates. Average sleep duration increased from 8.1 h in 1998 to 8.3 h in 2010. Average screen time increased from 140 min in 1998 to 154 min in 2010. Sleep duration and screen time were positively related in both years. The percentage of people averaging less than 6 h sleep decreased from 9.6% in 1998 to 8.6% in 2010. Between 1998 and 2010, increases in screen time did not occur at the expense of sleep duration.