Epidemiology and mortality among dialysis patients with parathyroidectomy: Taiwan 
National Cohort Study

Parathyroidectomy (PTx) is usually necessary in patients with end-stage renal disease (ESRD) on dialysis. Risk factors for higher PTx rates are controversial. The objectives of this study were to identify the risk factors for PTx in patients on dialysis and evaluate the mortality after PTx.

We analyzed data obtained from the National Health Insurance Research Database and included 35,162 ESRD dialysis patients. Kaplan-Meier method was used to calculate the incidence of PTx and survival rate after PTx. Cox proportional hazards models were used to identify the risk factors.

The PTx rate was 8.09 per 1,000 patient-years. Stratified on the basis of gender and diabetic mellitus (DM), the highest incidence rate of PTx was in females without DM. Stratified by age and DM, the highest incidence rate of PTx was in those aged 18-44 years without DM. The significant risk factors for PTx were younger age, female (hazard ratio (HR) 1.409, 95% confidence interval (CI): 1.257-1.580), DM (HR 0.479, 95% CI: 0.413-0.555), peritoneal dialysis (HR 1.657, 95% CI: 1.418-1.938) and hypertension (HTN) (HR 1.317, 95% CI: 1.162-1.492). The cumulative survival rates after PTx were 97.1%, 94.5%, 82.8% and 77.4% at the first, second, fifth and seventh year, respectively. Only age was significantly associated with higher mortality after PTx.

Higher PTx rates were found in dialysis patients who were female and younger, did not have DM, were on peritoneal dialysis and had HTN. Advanced age was associated with a higher mortality after PTx.