Perceived stress and mortality in a Taiwanese older adult population

Figures & data

Figure 1. Taiwan Longitudinal Study of Aging (TLSA), 1989–2007. †At each survey wave, efforts were made to contact and interview all respondents from the original cohorts (n = 4049 in 1989; n = 2462 in 1996; n = 1599 in 2003), even if they were lost to follow-up (LFU) in a previous wave. Thus, a person may be LFU in one survey wave, but interviewed in subsequent waves. This flowchart displays the inclusion of a refresher cohort in 2003, but no individuals from this cohort were included in the current study. Our analytic sample includes only respondents who were interviewed in at least one of the following waves: 1999, 2003 and 2007.

Table 1. Sociodemographic characteristics and health status of the study population.

	1999 n = 4132	2003 n = 3255	2007 n = 2915
Fixed baseline characteristics
Male (%)	50.7
Education (years)	5.0 (4.5)
Time varying covariates
Age (years)	68.6 (9.2)	72.3 (8.6)	74.4 (8.2)
Married (%)	69.2	72.0	69.0
Medical conditions (0–7)^a	0.9 (1.1)	0.9 (1.1)	1.1 (1.1)
Mobility limitations (0–8)	2.2 (2.5)	2.0 (2.4)	2.1 (2.5)
Depressive symptoms (0–30)	5.4 (6.1)	4.8 (5.6)	4.8 (5.7)
Emotional support (4–20)	7.3 (2.9)	7.6 (2.9)	7.4 (2.7)
Currently smoking (%)	24.1	19.1	15.4
Currently consuming alcohol (%)	24.2	23.7	23.9
Perceived stress
Mean (SD):
Full index (0–12)^b	1.8 (2.1)	1.7 (2.0)	1.6 (1.9)
Index excluding own health (0–10)	1.3 (1.7)	1.2 (1.6)	1.1 (1.5)
Died by end 2010 (%)	16.0

Means (SD) presented, unless stated otherwise.

^aMedical conditions included hypertension, diabetes, cardiovascular disease, stroke, cancer, liver disease, kidney disease.

^bPerceived stress – Full Index included reported stress on any of 6 perceived stress domains pertaining to the respondent’s: own health; own financial situation; own job; family member's health, financial situation, job, marriage, etc.; relationship with family members; and any other domain.

Table 2. Hazard ratios from Gompertz models predicting age-specific mortality (between 1999 and the end of 2010) from perceived stress as a time varying measure.

	Model I		Model II		Model III
Predictor	HR	95% CI	HR	95% CI	HR	95% CI
Fixed baseline characteristics
Male	1.92*	1.68–2.21	2.49*	2.17–2.86	2.38*	2.04–2.76
Education	0.97*	0.96–0.98	0.98	0.97–1.00	0.98	0.97–1.00
Time varying covariates
Control variables
Survey wave	0.98*	0.96–0.99	0.97*	0.95–0.99	0.97*	0.95–0.99
Married	1.02	0.98–1.05	1.01	0.98–1.05	1.01	0.98–1.05
Medical conditions			1.13*	1.08–1.19	1.13*	1.08–1.19
Mobility limitations			1.22*	1.19–1.26	1.21*	1.18–1.25
Depressive symptoms			1.02*	1.01–1.04	1.02*	1.01–1.03
Emotional support					1.01	0.99–1.03
Currently smoking					1.28*	1.10–1.49
Currently consuming alcohol					0.77*	0.66–0.91
Perceived stress^a	1.19*	1.13–1.26	0.94	0.87–1.01	0.94	0.87–1.01
Gamma for age (time clock)	0.09*	0.09–0.10	0.07*	0.06–0.08	0.07*	0.06–0.08

HR = Hazard ratio; CI = Confidence interval.

*p < 0.05.

^aStandardized (M = 0, SD = 1).