Table 6.

Incremental costs associated with treatment^a

	Annual cost difference
	Least	Greatest
Hydroxyurea (mean)
Total [22–24, 49]  Inpatient [22, 23, 49]  Outpatient [22, 23, 49]  Pharmacy [22, 23]  ED [22, 23]	− $2343 [49] − $2867 [23] − $60 [23] $194 [22] − $59 [23]	− $41,000 [24] − $6277 [22] $3098 [22] $325 [23] − $722 [22]
Transfusion (mean)
Total [51]	− $25,470	–
HSCT (median)
Total [54, 56]  Inpatient [54, 55]  Outpatient [54]	− $20,833 [56] − $8033 [54] $512	− $37,801 [56] − $25,575 [55] − $6504

Costs reflect the differences with treatment as the baseline (with treatment minus without treatment). No treatment category includes studies that reported results stratified by adherence, and included the non-adherent category, defined as MPR <80% or lowest tertile [43]. [43–46] Cost savings due to hydroxyurea versus no hydroxyurea. [48] Cost savings due to transfusion plus hydroxyurea versus hydroxyurea alone. [51, 52] Cost savings pre- versus post-HSCT. [53] Cost savings HSCT versus no HSCT. All costs were adjusted to 2019 US$ using the Consumer Price Index. For additional details and study-specific adjustments, see Appendix Table B3

ED emergency department, HSCT hematopoietic stem cell transplant, MPR medication possession ratio

^aTreatment category includes studies that reported results stratified by adherence, and included the adherent category, defined as MPR ≥80% or highest tertile [43]