I'm not sure I understand your reasoning here.the patients...

I'm not sure I understand your reasoning here.

the patients had chronic lower back pain (as opposed to acute) - some of these patients had the issue for more than 5 years yet still saw good pain relief.

the patients were defined to have chronic back pain if they had failed conservative treatment for more than 6 mths - this includes anti inflammatory treatments (which I believe steroids are).

steroid injection into the spine < 2 weeks prior was an exclusion criteria however that does not preclude patients that failed steroid treatment previously ie > 2 weeks prior to the trial.

so in essence, steroid non responders were included into the trial...