Table 1.

Search strategy used to locate articles in the database of MEDLINE/PubMed*

Participants	Aged ≥60 years	aged [mesh terms] OR aged [all fields] OR geriatrics [mesh terms] OR geriatrics [all fields] OR elderly [all fields] OR ‘older age’ [all fields] OR ‘older adult’ [all fields] OR ‘older adults’ [all fields] OR ‘older person’ [all fields] OR ‘older people’ [all fields] OR ‘older man’ [all fields] OR ‘older men’ [all fields] OR ‘older woman’ [all fields] OR ‘older women’ [all fields] OR aging [mesh terms] OR aging [all fields] OR ageing [all fields]
Exposure	Sleep duration	sleep [mesh terms] OR sleep [all fields] OR sleep disorders [mesh terms] OR ‘sleep disorders’ [all fields] OR ‘sleep duration’ [all fields] OR insomnia [all fields] OR drowsiness [all fields] OR drowse [all fields] OR napping [all fields] OR nap [all fields] OR naps [all fields] OR siesta [all fields]
Outcome	Mortality	mortality [mesh terms] OR mortality [all fields] OR death [mesh terms] OR death [all fields] OR deaths [all fields]
Design	Cohort studies	cohort studies [mesh terms] OR cohort [all fields]
Filters	Publication date	01/01/1980–31/08/2015

*Similar strategies were used to perform the search in the EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature) and IBECS (Bibliographic Index on Health Sciences from Spain) databases.