As part 1 of the patients’ regularly scheduled visits to their primary care clinician the professional staff obtained characteristics such as height and weight. Either the patients completed the study questionnaire and it was immediately reviewed by the research staff or the nursing staff completed it while interviewing the patients. The staff attempted to select consecutive patients. The questionnaire inquired about (1) basic demographics; (2) the presence, frequency, and duration of naps; (3) bed time, wake time, and total estimated sleep time per 24 hours; (4) general medical problems; (5) diagnosed sleep disorders; and (6) sleep hygiene issues, which included the use of caffeine, tobacco, alcohol, and weight loss products. Questionnaire data were entered in a single database for analysis. Of the 1001 questionnaires administered, 929 had the key items completed (ie, age, sex, weight, height, and total sleep time per 24 hours [TST] during the workweek and weekend). A preliminary review identified 5 weekday sleep times that were statistical outliers (105, 870, 900, 960, and 1200 minutes). As these values suggested errors in completion, transcription, or understanding of the questions, the patients who reported these sleep times were dropped from the analysis, leaving 924 participants. Weekday but not weekend sleep time was recorded for 3 participants, for whom we used the weekday sleep values also for the weekend. In the analysis, total weekday and weekend sleep times were combined with appropriate weighting for the number of days.