Arnow, Katherine

Importance Primary hyperparathyroidism (PHPT) is common and contributes to skeletal and kidney end-organ damage. Although parathyroidectomy can mitigate these complications, many patients are managed with observation, and real-world data on the population-based frequency and timing of end-organ damage under usual care are limited. Objective To evaluate the frequency and timing of end-organ damage associated with PHPT. Design, Setting, and Participants This cohort study included a population-based cohort identified from national electronic health record (EHR) and claims data (2010-2023) with follow-up through 2023. Participants were adults with a new biochemical diagnosis of PHPT. Data analysis was performed from August 2025 to April 2026. Exposure A new biochemical diagnosis of PHPT was defined as an elevated PTH (>65 pg/mL) within 1 month after a second elevated calcium level (serum calcium >10.2 mg/dL or ionized calcium >1.3 mmol/L or >5.3 mg/dL). Main Outcomes and Measures PHPT-associated end-organ damage (osteoporosis, atraumatic fractures, kidney stones, stage 3 or worse chronic kidney disease) at or after PHPT diagnosis using EHR or claim codes and laboratory data, in addition to the frequency and timing of parathyroidectomy. Results A total of 43 399 patients with PHPT were identified (mean [SD] age, 67.9 [12.5] years; 33 854 [78%] female and 9545 [22%] male), of whom 22 279 (51.3%) had end-organ damage at diagnosis. Among 21 120 patients without end-organ damage at diagnosis, 6762 (32.0%) progressed to end-organ damage after a median (IQR) 516 (166-1125) days. Only 4442 patients (19.9%) with end-organ damage at diagnosis were treated with parathyroidectomy. Among those who progressed to end-organ damage, 1348 (19.9%) underwent subsequent parathyroidectomy, which occurred a median (IQR) 154 (41-439) days later. Conclusions and Relevance In this national cohort of adults with a biochemical diagnosis of PHPT, 67% had PHPT-associated end-organ damage at diagnosis or on follow-up. Despite this, parathyroidectomy was uncommon. These findings may inform strategies to optimize utilization of parathyroidectomy and mitigate PHPT-associated morbidity.

ImportanceCancer imposes a substantial economic burden on patients that may be worse in patients with higher-stage disease due to the need for more therapy.ObjectiveTo investigate the out-of-pocket costs (OOPCs) attributable to the initial treatment of common cancers among privately insured individuals diagnosed at different stages.Design, Setting, and ParticipantsThis retrospective cohort study used administrative claims data of a large national insurer in the US linked to the Surveillance, Epidemiology, and End Results (SEER) cancer registry to compare OOPCs of individuals diagnosed with breast, colorectal, and lung cancer at different stages with OOPCs of similar individuals without cancer using difference-in-differences methods. Individuals living in the US between 2008 and 2022, aged younger than 65 years, insured through a large national private health insurer, and with 6 or more months of continuous enrollment were included. Data were analyzed from June 2024 through February 2025.ExposureThe presence or absence of an incident cancer diagnosis and disease stage from the SEER registry diagnosed from 2008 to 2019.Main Outcomes and MeasuresThe primary outcome was OOPCs among individuals with breast, colorectal, and lung cancer diagnosed at different disease stages compared with those with no cancer diagnosis.ResultsThe cohort consisted of 46 158 patients (mean [SD] age at diagnosis, 46 [12] years; 30 733 female [66.6%]; 2543 Asian [5.5%], 4114 Black [8.9%], 3590 Hispanic [7.8%], and 31 099 White [67.4%]), including 19 656 patients with cancer and 26 502 patients without cancer in the control group. Among patients with cancer, 14 581 patients had breast cancer, 2842 patients had colorectal cancer, and 2233 patients had lung cancer. An incident cancer diagnosis was associated with a mean increase in OOPCs of $592.53 per month (95% CI, $528.01-$627.04 per month) for the 6 months after the diagnosis. Cost monotonically increased with stage at diagnosis (mean OOPC increase range, $462.01 per month [95% CI, $417.92-$506.11 per month] for stage 0 to $719.97 per month [95% CI, $626.11-$813.83 per month] for stage 4).Conclusions and RelevanceIn this study of individuals with private insurance, patients faced high OOPCs after an incident diagnosis of cancer, with patients with more advanced cancer having the highest OOPCs. Further research is needed to determine the clinical and financial effects of increased OOPCs for patients with cancer.