Table 1.

Demographic and lifestyle parameters by occupational groups on board

	Day workers (54 engine room personnel, 16 electricians, five galley staff)	Watchkeepers (46 nautical officers, 77 deck ratings)
Number, n (%)	75 (37.9%)	123 (62.1%)
Age; median years (min–max)	44 (19–67)	35 (19–63)
Body mass index; median (min–max)	26 (19–40)	24 (17–36)
Morning-Evening-Questionnaire, n (%)
Morning type	45 (60.0%)	68 (55.2%)
Intermediate type	24 (32.0%)	46 (37.4%)
Evening type	6 (8.0%)	9 (7.4%)
Origin; n (%)
European	38 (50.7%)	47 (38.2%)
Southeast Asian	37 (49.3%)	76 (61.8%)
Married; n (%)	53 (70.7%)	87 (70.7%)
Children; n (%)	53 (70.7%)	82 (66.7%)
Smoking status; n (%)
Never smoked	36 (48.0%)	65 (52.8%)
Former smoker/smoker	39 (52.0%)	58 (47.2%)