Economic burden of growth hormone deficiency in a US pediatric population

BACKGROUND: Pediatric growth hormone deficiency (GHD) is a rare disorder of short stature that is currently treated with daily injections of somatropin. In addition to short stature, GHD is associated with other comorbidities such as impaired musculoskeletal development, cardiovascular disease, and decreased quality of life. OBJECTIVE: To analyze somatropin utilization, adherence, and health care costs among children with GHD who had either Medicaid or commercial health insurance. METHODS: Children (aged < 18 years) with a GHD diagnosis between January 1, 2008, and December 31, 2017, were identified in the IBM MarketScan Commercial and Medicaid databases. Patients with at least 12- and 6-month continuous enrollment pre- and postdiagnosis were eligible. Children with GHD were direct matched (1:3) to controls without GHD (or other short stature-related disorders) on age, gender, plan type, region, and race (Medicaid only). Index date was the date of the first GHD diagnosis during the selection window for GHD patients and using random assignment for controls. Patients were followed until the end of continuous database enrollment or December 31, 2018. Baseline comorbidities and medications were measured during the 12 months pre-index, whereas somatropin treatment patterns along with all-cause and GHD-related health care costs were measured during the variable follow-up period. Multivariable modeling was used to compare costs between GHD patients and controls and between somatropin-treated and -untreated GHD patients while adjusting for baseline characteristics. RESULTS: There were 6,820 Medicaid and 14,070 commercial patients with GHD who met the study inclusion criteria. Mean (SD) age at index was 9.5 (4.5) years for Medicaid patients and 11.1 (3.7) years for commercial patients. The majority of patients were male (> 65%), and mean follow-up time for all cases and controls was 3-4 years. Overall, 63.2% of Medicaid and 68.4% of commercial GHD patients were treated with somatropin at some point during follow-up. Among Medicaid GHD patients, the treatment rate was highest among White males and lowest among Black females. Adherence was low as the proportion of days covered was ≥ 80% for only 18.4% of Medicaid patients and 32.3% of commercial patients and 49.1% of treated Medicaid and 24.3% of treated commercial patients discontinued before turning age 13. After adjusting for baseline characteristics, all-cause non-somatropin annualized costs were 5.67 times higher (Δ$19,309) for Medicaid GHD patients and 5.46 times higher (Δ$12,305) for commercial GHD patients than matched non-GHD controls. Adjusted all-cause non-somatropin annualized costs were 0.59 times lower (Δ$14,416) for treated Medicaid patients and 0.69 times lower (Δ$7,650) for treated commercial patients than for untreated patients. CONCLUSIONS: Pediatric GHD presents a significant health care burden, and many patients remain untreated or undertreated. Untreated GHD was associated with higher non-somatropin health care costs than treated GHD. Strategies to optimize treatment and improve adherence may reduce the health care burden faced by these patients.