Table 4. Association between change in the number of healthy behaviors over midlife and onset of frailty over a mean follow-up of 16 years.

Number of healthy behaviors		N frail/N total	Frail %	Model 1†		Model 2‡		Model 3§
In 1985, mean age = 44.4 years	In 1997*, mean age = 54.8 years			HR (95% CI)	p	HR (95% CI)	p	HR (95% CI)	p
0–1	0–1	66/422	15.64	1 (ref)		1 (ref)		1 (ref)
0–1	2	51/555	9.19	0.61 (0.42–0.90)	0.01	0.63 (0.43–0.92)	0.02	0.64 (0.44–0.94)	0.02
0–1	3–4	38/426	8.92	0.56 (0.37–0.85)	0.007	0.57 (0.37–0.87)	0.009	0.57 (0.38–0.87)	0.009
2	0–1	25/248	10.08	0.65 (0.41–1.04)	0.71	0.66 (0.41–1.05)	0.08	0.69 (0.43–1.10)	0.12
2	2	84/999	8.41	0.54 (0.38–0.75)	<0.001	0.54 (0.39–0.76)	<0.001	0.57 (0.41–0.81)	0.001
2	3–4	79/1,329	5.94	0.35 (0.24–0.50)	<0.001	0.36 (0.25–0.51)	<0.001	0.37 (0.26–0.53)	<0.001
3–4	0–1	7/72	9.72	0.66 (0.29–1.48)	0.31	0.67 (0.29–1.52)	0.34	0.56 (0.25–1.27)	0.17
3–4	2	29/545	5.32	0.39 (0.25–0.62)	<0.001	0.39 (0.25–0.63)	<0.001	0.41 (0.26–0.65)	<0.001
3–4	3–4	85/1,839	4.62	0.29 (0.21–0.42)	<0.001	0.30 (0.21–0.43)	<0.001	0.32 (0.23–0.46)	<0.001

*Or in 1991 (N = 905) or in 2002 (N = 150) if missing data in 1997.

^†Model 1: age as timescale, adjusted for sex, ethnicity, marital status, and wave of second measurement of health behaviors.

^‡ Model 2: model 1 additionally adjusted for education and occupational position.

^§ Model 3: model 2 additionally adjusted for the number of morbidities at the second measurement of health behaviors.

Abbreviations: CI, confidence interval; HR, hazard ratio; ref, reference