Yoga, Health-Related Quality of Life and Mental Well-Being: A Re-analysis of a Meta-analysis Using the Quality Effects Model

Abstract

Background: Provide robust and practically relevant information regarding the association between yoga, health-related quality-of-life (HRQOL), and mental well-being (MWB) in older adults.

Methods: Data were derived from a recent meta-analysis of 12 randomized controlled yoga trials representing 752 adults ≥60 years of age. Standardized mean difference effect sizes (ESs) were pooled using the recently developed quality effects model and 95% compatibility intervals (CI). Small-study effects were examined using the Doi plot and Luis Furuya-Kanamori (LFK) index. Sensitivity and cumulative meta-analyses were conducted as well as percentile improvement, number needed to treat (NNT), and number to benefit. The grading of recommendations assessment, development, and evaluation (GRADE) instrument was used to assess the strength of the evidence.

Results: Yoga was associated with improvements in both HRQOL (ES = 0.51, 95% CI, 0.25-0.77, I2 = 63.1%) and MWB (ES = 0.39, 95% CI, 0.15-0.63, I2 =56.2%). Percentile improvements were 19.5 for HRQOL and 15.3 for MWB whereas the NNT was 4 for HRQOL and 5 for MWB. An estimated 378,222 and 302,578 U.S. yoga-practicing adults ≥65 years of age could potentially improve their HRQOL and MWB, respectively. Major asymmetry suggestive of small-study effects was observed for MWB but not HRQOL. Further examination for asymmetry revealed that greater improvements in MWB were associated with more (151 vs. 68) minutes of yoga per week (p = .007). Overall strength of evidence was considered "high" for HRQOL and "moderate" for MWB.

Conclusions: Yoga is associated with improvements in HRQOL and MWB among older adults, with approximately 150 minutes or more per week possibly optimal.

Keywords: Outcomes; Physical activity; Successful aging; Systematic review.