Table 4. Odds Ratios (95% CIs) of Healthy Aging by History of Rotating Night Shift Work in the Nurses’ Health Study (1988-2000).

Outcome	No.	Healthy aging, No. (%)	Base adjusteda	Multivariate adjustedb	Multivariate and BMI adjustedc
Healthy aging by duration of shift work, y
0	5477	553 (10.1)	1 [Reference]	1 [Reference]	1 [Reference]
1-5	5722	608 (10.6)	1.03 (0.91-1.17)	1.00 (0.88-1.13)	1.00 (0.89-1.14)
6-9	1044	80 (7.7)	0.75 (0.59-0.97)	0.72 (0.56-0.92)	0.75 (0.59-0.97)
≥10	2030	145 (7.1)	0.75 (0.62-0.91)	0.73 (0.60-0.89)	0.78 (0.64-0.95)
P for trend	NA	NA	<.001	<.001	.003
No main chronic diseases by duration of shift work, y
0	5477	3291 (60.1)	1 [Reference]	1 [Reference]	1 [Reference]
1-5	5722	3563 (62.3)	1.08 (1.00-1.17)	1.07 (0.99-1.16)	1.07 (0.99-1.16)
6-9	1044	572 (54.8)	0.81 (0.71-0.93)	0.80 (0.70-0.92)	0.82 (0.72-0.95)
≥10	2030	1089 (53.7)	0.82 (0.74-0.91)	0.84 (0.75-0.93)	0.87 (0.78-0.97)
P for trend	NA	NA	<.001	<.001	<.001
Good physical function by duration of shift work, y
0	5477	1351 (24.7)	1 [Reference]	1 [Reference]	1 [Reference]
1-5	5722	1474 (25.8)	1.03 (0.94-1.12)	0.99 (0.90-1.08)	0.99 (0.91-1.08)
6-9	1044	216 (20.7)	0.81 (0.69-0.95)	0.76 (0.64-0.90)	0.80 (0.68-0.95)
≥10	2030	413 (20.3)	0.85 (0.75-0.96)	0.81 (0.71-0.92)	0.88 (0.77-1.00)
P for trend	NA	NA	.001	<.001	.008
Good mental health by duration of shift work, y
0	5477	2085 (38.1)	1 [Reference]	1 [Reference]	1 [Reference]
1-5	5722	2181 (38.1)	0.99 (0.92-1.07)	0.98 (0.91-1.06)	0.98 (0.91-1.06)
6-9	1044	356 (34.1)	0.85 (0.74-0.98)	0.85 (0.74-0.98)	0.85 (0.74-0.98)
≥10	2030	695 (34.2)	0.90 (0.80-0.99)	0.92 (0.82-1.03)	0.92 (0.82-1.03)
P for trend	NA	NA	.009	.03	.03
Good cognitive function by duration of shift work, y
0	5477	4266 (77.9)	1 [Reference]	1 [Reference]	1 [Reference]
1-5	5722	4514 (78.9)	1.02 (0.93-1.12)	1.01 (0.92-1.11)	1.01 (0.92-1.11)
6-9	1044	788 (75.5)	0.87 (0.74-1.02)	0.88 (0.75-1.03)	0.88 (0.75-1.04)
≥10	2030	1488 (73.3)	0.86 (0.76-0.97)	0.89 (0.78-1.00)	0.90 (0.79-1.02)
P for trend	NA	NA	.003	.02	.03

Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); NA, not applicable.

^a Base model adjusted for age at baseline (continuous); educational level (registered nurse, bachelor’s, or master’s or doctorate degree); marital status (married, widowed, or separated/divorced/never married); household income (quintiles); baseline hypertension and high cholesterol (yes or no); family history of cancer, myocardial infarction, and diabetes (yes or no); menopausal status and hormone use (premenopausal, postmenopausal never users, postmenopausal past users, or postmenopausal current users); and aspirin use (regular use or not).

^b Multivariate model additionally adjusted for lifestyle factors, including smoking history (never, former smoker, or current smoker), alcohol intake (none, 1-14.9 g/d, or ≥15 g/d), total energy intake (quintiles), diet quality (Alternate-Healthy Eating Index score, in quintiles), physical activity (metabolic equivalent hours per week, in quintiles); standing and sitting time (in quintiles); and sleep duration (≤5, 6, 7, 8, or ≥9 hours).

^c Additionally adjusted for BMI at baseline (<18.5, 18.5-24.9, 25-29.9, or ≥30).