Study Lepper (1998): study US California 1993
- Public:
- Retirees, Southern California, USA, followed 9 months199?
- Sample:
- Respondents:
- N = 971
- Non Response:
- Assessment:
-
Questionnaire: paper
Mailed questionnaire
Correlate
- Authors's label
- Sleep disturbances
- Our Classification
-
-
- Operationalization
- Self report on 3 questions:
How much of the time during the previous weeks
a enough sleep was obtained in order to feel rested upon waking
b had trouble falling asleep
c got the amount of sleep needed