Tran 2015.

Population (low back pain description; location; setting; data collection period)	Prospective cohort: People with chronic low back pain at an academic safety‐net hospital, and affiliated community health centers; United States of America; Primary care; Data collection period not reported
Sample size	63 (twice‐weekly yoga); 30 (once‐weekly yoga)a
Prognostic factor (type, measure(s) of individual recovery expectations)	TREATMENT: How helpful do you expect yoga to be for your back problems? (0 ‐ 10)
Notes	Funding Source: The National Center for Complementary and Alternative Medicine; The National Institiutes of Health Conflict of Interest: None declared aTran 2015a (twice‐weekly yoga) and Tran 2015b (once‐weekly yoga) are same study, presented separately bStudy does not present sufficient data to be included in meta‐analyses (multivariate), but does provide some measure of statistical significance