Paired Comparison Survey Analyses Utilizing Rasch Methodology of the Relative Difficulty and Estimated Work Relative...

Minimally invasive sacroiliac joint arthrodesis ("MI SIJ fusion") received a Category I CPT^® code (27279) effective January 1, 2015 and was assigned a work relative value unit ("RVU") of 9.03. The International Society for the Advancement of Spine Surgery ("ISASS") conducted a study consisting of a Rasch analysis of two separate surveys of surgeons to assess the accuracy of the assigned work RVU.

A survey was developed and sent to ninety-three ISASS surgeon committee members. Respondents were asked to compare CPT^® 27279 to ten other comparator CPT^® codes reflective of common spine surgeries. The survey presented each comparator CPT^® code with its code descriptor as well as the description of CPT^® 27279 and asked respondents to indicate whether CPT^® 27279 was greater, equal, or less in terms of work effort than the comparator code. A second survey was sent to 557 U.S.-based spine surgeon members of ISASS and 241 spine surgeon members of the Society for Minimally Invasive Spine Surgery ("SMISS"). The design of the second survey mirrored that of the first survey except for the use of a broader set of comparator CPT^® codes (27 vs. 10). Using the work RVUs of the comparator codes, a Rasch analysis was performed to estimate the relative difficulty of CPT^® 27279, after which the work RVU of CPT^® 27279 was estimated by regression analysis.

Twenty surgeons responded to the first survey and thirty-four surgeons responded to the second survey. The results of the regression analysis of the first survey indicate a work RVU for CPT^® 27279 of 14.36 and the results of the regression analysis of the second survey indicate a work RVU for CPT^® 27279 of 14.1.

The Rasch analysis indicates that the current work RVU assigned to CPT^® 27279 is undervalued at 9.03. Averaging the results of the regression analyses of the two surveys indicates a work RVU for CPT^® 27279 of 14.23.