Understanding Provider Cost of MRI for Appendicitis in Children: A Time-Driven Activity-Based Costing Analysis

Objective

To use time driven activity-based costing to characterize the provider cost of rapid MRI for appendicitis compared to other MRI examinations billed with the same Current Procedural Terminology codes commonly used for MRI appendicitis examinations.

Methods

Rapid MRI appendicitis examination was compared with MRI pelvis without intravenous contrast, MRI abdomen/pelvis without intravenous contrast, and MRI abdomen/pelvis with intravenous contrast. Process maps for each examination were created through direct shadowing of patient procedures (n = 20) and feedback from relevant health care professionals. Additional data were collected from the electronic medical record for 327 MRI examinations. Practical capacity cost rates were calculated for personnel, equipment, and facilities. The cost of each step was calculated by multiplying the capacity cost rate with the mean duration of each step. Stepwise costs were summed to generate a total cost for each MRI examination.

Results

The mean duration and costs for MRI examination type were as follows: MRI appendicitis: 11 (range: 6-25) min, $20.03 (7.80-44.24); MRI pelvis without intravenous contrast: 55 (29-205) min, $105.99 (64.18-285.13); MRI abdomen/pelvis without intravenous contrast: 65 (26-173) min, $144.83 (61.16-196.50); MRI abdomen/pelvis with intravenous contrast: 128 (39-303) min, $236.99 (102.62-556.54).

Conclusion

The estimated cost of providing a rapid appendicitis MRI examination is significantly less than other MRI examinations billed using Current Procedural Terminology codes typically used for appendicitis MRI. Mechanisms to appropriately bill rapid MRI examinations with limited sequences are needed to improve cost efficiency for the patient and to enable wider use of limited MRI examinations in the pediatric population.