MATERIAL and METHODS: This was a retrospective analysis of plain radiographs obtained from patients implanted with intrathecal catheters and morphine pumps. Each plain radiograph was assessed independently by three raters with varying expertise, at three different time points, to confirm the position of the intrathecal catheter tip. Krippendorff?s alpha coefficient was used to calculate both the interrater and intrarater reliability.

RESULTS: There was a high level of agreement among the three raters and the three reviews of each rater separately when assessing the location of intrathecal catheter tips in plain radiographs from 126 patients. This was evidenced by the Krippendorff?s alpha value being >0.99 in all cases, which was greater than the cutoff threshold value of 0.8.

CONCLUSION: The interrater and intrarater reliability of plain radiographs for determination of catheter tip position after IDDS implantation was high. The experience and expertise of the raters did not significantly affect the assessments. Keywords : Intrathecal, Reliability, Neuromodulation, Catheters, Chronic pain