The Accuracy and Usefulness of the National Comprehensive Cancer Network Evidence Blocks Affordability Rating

The National Comprehensive Cancer Network (NCCN) Guidelines' Evidence Blocks has the broadest scope of the several oncology value assessment frameworks. The Evidence Blocks includes the Affordability criterion, which reflects the financial cost of each treatment on a 1-5 scale. The accuracy of Affordability is unknown.

We calculated Medicare costs for all first-line and maintenance treatments for the 30 cancers with the highest incidence in the USA that had published NCCN Evidence Blocks as of 31 December 2018. We assessed the accuracy and consistency of Affordability across different treatments and cancer types. Among different treatments for the same indication, we determined the frequency with which the Affordability assessment was consistent with calculated treatment costs.

There were a total of 1386 treatments in our sample. Lower Affordability scores were associated with higher costs. There was significant variation in cost at each level of Affordability; for treatments with Affordability = 1 (very expensive), costs ranged from $US4551 to $US43,794 per month for treatments administered over an undefined time period and from $US2865 to $US500,982 per course of therapy for treatments administered over a defined time period. Among treatments for the same indication, Affordability was discrepant with calculated treatment costs in 7.9% of pairwise comparisons, identifying the higher-cost treatment as being more affordable. Discrepancies were reduced when we reassigned Affordability scores based on calculated treatment costs.

Evidence Blocks Affordability generally correlated with treatment costs but contained discrepancies, which may limit its usefulness to clinicians in comparing costs. This study suggests that the Affordability score may be improved by indexing more directly to specified dollar value thresholds.