a broad-based population. Virtually all are experimental
studies in which participants are offered training in a
specific technique and encouraged to practice it regularly
over a relatively short period of time, typically 3 months or
less. Randomized, experimental/control studies are valuable
for demonstrating that the effect is due to the intervention
rather than to the characteristics of the individuals.
Nonetheless, it is important to determine whether the
demonstrated benefits carry over to those in the general
population who incorporate relaxation practice into their
everyday lives.
In this study, the link between relaxation practice and
physiologic regulation in a large, nationally representative
sample of older persons in Taiwan is examined. The effect of
relaxation practice with other types of exercise is compared.
A substantial number of the respondents report practicing a
relaxation technique (n = 140, 14%); nearly half of these
practitioners began more than 5 years before the study, and
the majority practice each day. The data include 26 markers
of physiologic regulation across multiple systems. In addition
to sociodemographic confounders, ther was control for a
wide range of self-reported and performance-based health
indicators in order to address potential reverse causality (i.e.,
healthy people may be more likely to practice relaxation
techniques).
Materials and Methods
Data
The 2006 wave of the Social Environment and Biomarkers
of Aging Study comprised a nationally representative sample
of Taiwanese aged 53 and older; persons aged 77 and
older and urban residents were oversampled. It was based
on a random sample of participants in the ongoing Taiwan
Longitudinal Study on Aging, which began in 1989; younger
refresher cohorts were added in 1996 and 2003. The 2006
sampling frame included (1) an older cohort (aged 60 +) of
respondents from the 1999 survey who completed the 2000
medical examination and (2) a younger cohort (aged 53–60)
of respondents first interviewed in 2003. Figure 1 gives details
regarding response rates and attrition.
Among the 1,284 respondents who completed the 2006
interview, 1036 (81%) participated in the physical examination;
3 died before the examination, 32 were not eligible
because of a health condition, and 213 declined. Participation
in the examination was lower among both the
youngest (aged 53–59) and the oldest (80 + ) respondents,
less-educated respondents, and those with limitations in
activities of daily living, but, in the presence of controls
for age, participation did not differ significantly by selfreported
health status.17