Association of Yoga Practice with Mortality in a Nationally Representative Sample of US Adults
METHODS: Data were obtained from the 2002 Alternative Medicine Supplement of the National Health Interview Survey (NHIS) and linked to the National Death Index through year 2006 (n=28,790 with 1,377 dead at follow-up). NHIS participants were asked if they had engaged in meditation and in yoga in the previous 12 months. Cox regression was used to model survival with adjustment for survey design, education, race/ethnicity, gender, and age. Additional analyses were performed with adjustment for smoking status, number of co-existing health conditions, and for whether there was a specific health reason for yoga practice.
RESULTS: In initial multivariable analyses, yoga practice was significantly associated with better survival (Hazard Ratio: 0.67; 95% Confidence Interval: 0.48-0.93). After adjustment for smoking and co-morbidities, the effect was no longer significant. However, after further adjustment for the health reason for practice in addition to smoking and co-morbidities, yoga practice was again a predictor of better survival (0.57; 0.36-0.92). Those who engaged in both yoga and meditation did not have better survival rates than those who practiced yoga alone (1.31; 0.34-5.03).
CONCLUSIONS: Among practitioners of yoga, some of the improved survival outcomes could be accounted for by better health and health behaviors. However, after controlling for these factors, yoga practice was still associated with significantly improved survival among those who practiced it for a specific health condition. Improving accessibility of yoga practice for people with certain health conditions could provide a survival benefit.