Quantifying risk using FMEA: An alternate approach to AAPM TG-100 for scoring failures and evaluating clinical workflow

Abstract

Purpose: Renovation of the brachytherapy program at a leading cancer center utilized methods of the AAPM TG-100 report to objectively evaluate current clinical brachytherapy workflows and develop techniques for minimizing the risk of failures, increasing efficiency, and consequently providing opportunities for improved treatment quality. The TG-100 report guides evaluation of clinical workflows with recommendations for identifying potential failure modes (FM) and scoring them from the perspective of their occurrence frequency O, failure severity S, and inability to detect them D. The current study assessed the impact of differing methods to determine the risk priority number (RPN) beyond simple multiplication.

Methods and materials: The clinical workflow for a complex brachytherapy procedure was evaluated by a team of 15 staff members, who identified discrete FM using alternate scoring scales than those presented in the TG-100 report. These scales were expanded over all clinically relevant possibilities with care to emphasize mitigation of natural bias for scoring near the median range as well as to enhance the overall scoring-system sensitivity. Based on staff member perceptions, a more realistic measure of risk was determined using weighted functions of their scores.

Results: This new method expanded the range of RPN possibilities by a factor of 86, improving evaluation and recognition of safe and efficient clinical workflows. Mean RPN values for each FM decreased by 44% when changing from the old to the new clinical workflow, as evaluated using the TG-100 method. This decreased by 66% when evaluated with the new method. As a measure of the total risk associated with an entire clinical workflow, the integral of RPN values increased by 15% and decreased by 31% with the TG-100 and new methods, respectively.

Conclusions: This appears to be the first application of an alternate approach to the TG-100 method for evaluating the risk of clinical workflows. It exemplifies the risk analysis techniques necessary to rapidly evaluate simple clinical workflows appropriately.