The aim of this study was to evaluate the time to relieving pain intensity in patients with non-specific chronic low back pain treated by interferential current. Knowledge of the number of sessions needed for relieving pain intensity is very important because it can be used as a measure of treatment effectiveness, and assists the physiotherapist in choosing the best treatment to be used. The analysis was conducted on a sample of 150 patients with non-specific chronic low back pain, using the Cox proportional hazard model. All analysis were performed by the free software R.
