A meta-analysis of nearly 8,000 patients from published studies shows a mean improvement of 39 mm for VAS and 25.7 for ODI. The likelihood of complications was 0.064%. Furthermore, no cases of discitis were reported after oxygen-ozone therapy, which is unlike all the other methods of disc volume reduction. This is most likely due to the fact that ozone is a strong oxidizer and an excellent disinfecting agent. The complications shown in the meta-analysis were minor and transient, and easily avoidable by utilizing a device such as the AO-1000 that is designed to eliminate these types of complications (ozone leakage into the treatment room and high ozone concentrations) during this procedure. The estimated complication rate from the meta-analysis is consistent with the Italian Oxygen-Ozone Therapy Federation (FIO) results (no procedure-related adverse events in treatments on 15,000 patients).