The proportion of patients failing to achieve an MCID of six (6) points or more improvement in the MDQ change score for patients with low back pain treated during the observation period will be reported. Additionally, a risk-adjusted MCID proportional difference will be determined by calculating the difference between the risk model predicted and observed MCID proportion will reported for each physical therapist or physical therapy group. The risk adjustment will be calculated using a logistic regression model using: baseline MDQ score, baseline pain score, age, sex, payer, and symptom duration (time from surgery or injury to baseline physical therapy visit). These measures will serve as a physical or occupational therapy performance measure at the eligible physical or occupational therapist or physical or occupational therapy group level.