Population-level predictors of persistent hyperparathyroidism

BackgroundSystematic study of outcomes of initial surgery for primary hyperparathyroidism (PHPT) has been limited by selection and self-reporting biases. To avoid these biases, we evaluated parathyroidectomy (PTx) outcomes within an integrated health care system encompassing 3.25 million enrollees.MethodsAll patients undergoing PTx for PHPT from 1995 to 2010 were studied. Persistent and recurrent disease were defined by a serum calcium level >10.5 mg/dL before or after 6 months postoperatively, respectively. The effect of demographic, clinical, and hospital volume-related variables was assessed by the use of multivariate logistic regression.ResultsA total of 1,190 initial operations for PHPT were performed at 14 hospitals. Follow-up calcium levels were available in 97% of subjects. The overall success rate was 92%, and 5% of patients developed recurrent disease. Age ≥70 years was predictive of persistent disease (odds ratio 1.80, P < .05). High-volume hospital (>100 cases) predicted against persistent disease (odds ratio 0.42, P < .05) and carried 96% success rate. Negative or equivocal sestamibi scan was associated with a lower success rate (success rate 89% vs 95% for positive scan, P < .05). Reoperation was performed in 12% of patients with persistent or recurrent PHPT.ConclusionThe success rate of PTx is influenced by patient age, hospital volume, and sestamibi scan result. Surgical outcomes may be optimized by designating high-volume centers in the community setting.