Table 2.

Descriptive Statistics for Depression Rates, Sleep Parameters, Work Hours, and Perceived Medical Errors.

	Preinternship	3 Months	6 Months
Sample size	N = 1215 (nondepressed)	N = 933	N = 915
Depression rates (n, %)	---	151, 16.2%	151, 16.5%
PSQI > 5 (n, %)	222; 18·3%	---	---
Sleep duration (M ± SD)	7 hrs 22 mins ± 69 mins	6 hrs 25 mins ± 57 mins	6 hrs 28 mins ± 57 mins
Short sleep ≤ 6 h (n, %)	255, 21.0%	458, 49.1%	445; 48.6%
Work hours (weekly)	---	66 hrs 34 mins ± 16 hrs; Median: 70 hrs	65 hrs 25 mins ± 18 hrs; Median: 70 hrs
Perceived medical errors (positive)	---	n = 165/922; 17.9%	n = 180/900; 20.0%

Note. Depression rates indicated by Patient Health Questionnaire-9 ≥ 10. Poor sleep indicated by Pittsburgh Sleep Quality Index >5. Sleep deprivation ≤6 hr per night on average. Proportion of missing data at the two follow-up assessments was not found to be associated with baseline depression, sleep quality, age, or depression history (all p = NS).