Healthcare use and costs before and after parathyroidectomy in patients on dialysis

BACKGROUND Parathyroidectomy (PTX) is often performed in dialysis patients when medical treatment fails to control secondary hyperparathyroidism (SHPT). PTX is viewed by many as a cost-containing measure for patients who have been treated with vitamin D analogs and calcimimetics. Yet, information about health resource utilization and costs before and after PTX is limited. METHODS This retrospective cohort study used professional service and pharmacy claims to identify subjects on dialysis undergoing PTX from 1/1/2008-12/31/2010. Only subjects with at least six months of information before and after PTX were considered. Subjects with primary hyperparathyroidism or kidney transplant were excluded. Prescription use, physician encounters, and surgical complications were compared during the six months immediately before and after PTX. RESULTS The mean (SD) age of the 181 study subjects was 51 (15) years; 59% female; and 80% insured by Medicare. Overall, the percentage of patients receiving medications to manage altered mineral metabolism increased from 67% before to 79% after PTX. Specifically, oral vitamin D use increased, while the utilization of cinacalcet decreased resulting in mean (SD) monthly medication charges decreasing from $486 (507) to $226 (288) (p < 0.01). The mean (SD) number of physician encounters rose from 15 (14) before to 21 (22) per 6 months after PTX (p < 0.01) resulting in the corresponding increase in mean (SD) monthly charges from $1531 (2150) to $1965 (3317) (p = 0.08). Hypocalcemia was the predominant diagnosis recorded for post-surgical physician encounters occurring in 31% of all subjects; 84% of hypocalcemic episodes were managed in acute care facilities. CONCLUSIONS The cost of medications to manage SHPT decreased after PTX largely due to reduction in cinacalcet use, whereas vitamin D use increased likely to manage hypocalcemia. The frequency and cost of physician encounters, especially in acute care settings, were higher in the 6 months after PTX attributable largely to episodes of severe hypocalcemia. Overall, the reduction in prescription costs during the 6 months after PTX is outweighed by the higher costs associated with physician care.