The proportion of patients failing to achieve an MCID of two (2) points or more improvement in the NPRS 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. Six measures will be reported, two overall performance measures and four stratified performance measures are to be included: Rate 1: Overall proportion of patients achieving an MCID in NDI change score will be reported. Rate 2: A risk-adjusted MCID proportional difference will be reported where the difference between the risk model predicted and observed MCID (measured via NDI) proportion will reported. For operative (surgical) patients: Rate 3: The proportion of patients not achieving an MCID in NDI change score will be reported. Rate 4: A risk-adjusted MCID proportional difference will be reported where the difference between the risk model predicted and observed MCID (measured via NDI) proportion will reported. For non-operative (non-surgical) patients: Rate 5: The proportion of patients not achieving an MCID in NDI change score will be reported. Rate 6: A risk-adjusted MCID proportional difference will be reported where the difference between the risk model predicted and observed MCID (measured via NDI) proportion will reported.