Table 1.

Descriptive statistics at baseline: covariates

	Analytic sample n (%)	Mean late-life physical function (range 0–3)
All		2.3
Age at baseline (mean 54)
47–55	541 (67.4)	2.5
56–65	246 (30.6)	1.9
66–71	16 (2.0)	1.4
Sex
Women	417 (51.9)	2.3
Men	386 (48.1)	2.3
Physical working conditionsa
0	408 (50.8)	2.4
1	206 (25.7)	2.3
2	126 (15.7)	2.1
3	47 (5.9)	2.0
4	16 (2.0)	2.6
Level of education
Compulsory	249 (31.0)	2.1
Vocational	384 (47.8)	2.3
Upper secondary	93 (11.6)	2.4
University	77 (9.6)	2.6
Occupation-based social class
Blue-collar worker	306 (38.1)	2.2
White-collar worker	497 (61.9)	2.4
Smoking
No, never	370 (46.1)	2.4
Yes or yes but I have quit	433 (53.9)	2.2
Physical activity
No	99 (12.3)	2.0
Yes, but rarely	60 (7.5)	2.1
Yes, 1–3 times/month	56 (7.0)	2.1
Yes, once a week	224 (27.9)	2.4
Yes, several times a week	364 (45.3)	2.4

^aA 4-item index of physical working conditions (heavy lifting, exposure to vibrations, daily sweating, and other physically demanding work) that ranged from 0 to 4