INCREASED MORTALITY IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM: DOES SURGERY MAKE A DIFFERENCE?

Objective

Primary hyperparathyroidism (PHPT) is functionally characterized by an inappropriately raised secretion of parathyroid hormone, leading to raised serum calcium levels. Some patients are referred for parathyroidectomy, and some are managed conservatively. The aim of the audit was to compare the mortality outcomes between the two groups.

Methods

We retrospectively identified a cohort of inpatients with a main or secondary diagnosis of PHPT between 1986 and 2010 and followed them up to the end of 2011. The risk of mortality in PHPT patients compared to the background general population was estimated by calculating standardized mortality ratios (SMRs), adjusting for age, sex, and person-years at risk. Mortality in surgically treated patients was compared to conservatively treated patients using Cox regression, taking account of the Charlson Comorbidity Index.

Results

A total of 2,589 patients (77.9% females) were diagnosed with PHPT in Scotland over this period. Of patients diagnosed with PHPT, 41.6% (1,077/2,589) had died by the end of 2011. The SMR was 1.58 (95% confidence interval [CI], 1.48 to 1.67). A total of 54.8% of the patients underwent surgery (SMR, 1.30; 95% CI, 1.18 to 1.43), while the rest were treated "conservatively" (SMR, 1.88; 95% CI, 1.73 to 2.03) (P<.001). When other significant variables including the Charlson Comorbidity Index were taken into account in the final model, the hazard ratio for the "conservatively" managed group was reduced to 1.49 (95% CI, 1.30 to 1.70; P<.0001).

Conclusion

Our study confirmed that inpatients diagnosed with PHPT have increased mortality. The risk of mortality was lower in those treated surgically compared with patients treated conservatively. Abbreviations: CI = confidence interval; HR = hazard ratio; PHPT = primary hyperparathyroidism; PTX = parathyroidectomy; SMR = standard mortality ratio; SMR01 = Scottish Morbidity Records.