Clinical Burden and Practice Patterns in Patients With Chronic Hypoparathyroidism in the United States (US): A Claims Data Analysis Using Diagnosis-Based Criteria

Abstract

\n Objectives: Significant knowledge gaps exist regarding the comorbidities, treatment and lab testing patterns of patients with chronic hypoparathyroidism (cHP). This study describes a large cohort of patients with cHP identified using a diagnosis-based criteria from a claims database.\n Methods: This retrospective cohort study was conducted using a large (130 million individuals) claims database (HealthVerity Closed Payer Claim Medical and Pharmacy databases: Private Source 20) from Oct 2014 to Dec 2019. Eligible patients had ≥2 diagnosis claims of HP (ICD9/10 codes: E20.0, E20.8, E20.9, 252.1) that were 6–15 months apart, a prescription claim for either active vitamin D, calcium, PTH or thyroid replacement therapy between the first qualifying HP claim and within 30 days of the second HP claim, and continuous enrollment for one year before the index date (the date of the first of two qualifying HP diagnosis claims) and ≥16 months after. Patients were followed up to two years after the index date. Patient characteristics, comorbidities, lab testing and treatment patterns were descriptively analyzed.\n Results: Out of 43,640 patients with a diagnosis claim for HP, 4,118 patients met the eligibility criteria. The mean age of the cohort was 56.5 years + 18.6 (SD), and 76.4% were females, similar to data from other large cohort studies. The most common comorbidities during the 1-year follow-up were hypertension (56.0%), hypocalcemia (38.7%), cancer (30.5%, of which 24% were thyroid cancers), diabetes (29.4%), chronic pulmonary disease (24.1%), cardiac arrhythmias (17.4%), CKD stage 3–5 (17.0%), osteoporosis (9.6%) and neuropsychiatric disorders, including depressive disorders (22.0%), anxiety (21.6%), and sleep-wake disorders (18.4%). During the 1-year follow up, commonly monitored lab tests included serum calcium (89.9%), eGFR/creatinine (85.7%), 25-hydroxy vitamin D (61.1%), and intact PTH (43.9%). Remarkably, serum phosphorous (36.3%), serum magnesium (35.4%), and 24h-urine calcium (10.5%) were much less often monitored. In addition, BMD was measured in 10.9% patients. Also during the 1-year follow-up, 67.1% of patients had a prescription claim for thyroid replacement therapy, 60.5% for calcitriol, 15.7% for ergocalciferol, and 3.4 % for PTH.\n Conclusion: Findings from this study highlight the high comorbidity burden in cHP patients which aligns with the monitoring patterns. Kidney function appears to be a key concern and may be important when considering therapeutic intervention. The comorbidities and practice patterns observed in this study are consistent with the results obtained using a surgery-based approach to identify cHP patients in the same claims database. Future studies will also examine the economic burden of cHP.