Sleep Timing Across the Lifespan of Australian Adults.

The aim of this study was to examine sleep timing across the lifespan of Australian adults. A cross-sectional design was used to collect information on subjective sleep timing from 1225 participants (52.3% female) during a telephone interview. The participants were aged from 18 to over 80 and were grouped according to their age using 10-year increments (e.g., 18-29 y, 30-39 y, etc.). There was a diverse distribution across the lifespans, with the largest proportion of participants being from the 60-69 age group (22.8%). Participants were predominantly from New South Wales, Queensland, and Victoria. Younger adults reported going to bed later (p < 0.001) and waking up later than other age groups (p < 0.001). Wake times were earliest during middle adulthood (p < 0.001). There was no significant age effect on the minimum sleep required for good health (p = 0.159) and only a marginal decrease with age in the amount of sleep required to maintain a good mood (p = 0.041). In conclusion, these findings highlight significant variations in sleep timing across younger, middle-aged, and older Australian adults. The current findings could inform future Australian sleep health campaigns, in which the goal is to provide targeted strategies for age groups across their lifespans.