Testing a model of association between patient identified problems and responses to global measures of health in low back pain patients: a prospective study.

The Jonckheere-Terpstra test revealed a significant trend in the order of the median scores of task difficulty across the three usual activities groups at baseline (p = 0.015) and at 12 months (p < 0.001), and across change scores (p < 0.001).

also in 6,184 other papers