Figure 2.

Tornado diagram for potential cost savings per patient associated with considering SIJ in workup of chronic low back pain for preoperative lumbar fusion patient.

Notes: For each model parameter shown, the model was run using the lower and upper range of the plausible values. The plot shows the range of cost savings with the low/high assumptions. When the higher estimate shows higher savings, it is shown with a light gray bar. When the lower estimate shows higher savings, it is shown with a dark gray bar. Parameters are ordered (top to bottom) by their effect on the cost savings range, which produces the “tornado” shape from which the diagram draws its name.

Abbreviations: SIJ, sacroiliac joint; LF, lumbar fusion; SIJF, SIJ fusion.