title: The effect of parathyroidectomy on patient survival in secondary hyperparathyroidism.
abstract: BACKGROUND
  Secondary hyperparathyroidism is a common condition in patients with end-stage renal disease and is associated with osteoporosis and cardiovascular disease. Despite improved medical treatment, parathyroidectomy (PTX) is still necessary for many patients on renal replacement therapy. The aim of this study was to evaluate the effect of PTX on patient survival.
  
  
  METHODS
  A nested index-referent study was performed within the Swedish Renal Registry (SRR). Patients on maintenance dialysis and transplantation at the time of PTX were analysed separately. The PTX patients in each of these strata were matched for age, sex and underlying renal diseases with up to five referent patients who had not undergone PTX. To calculate survival time and hazard ratios, indexes and referents were assigned the calendar date (d) of the PTX of the index patient. The risk of death after PTX was calculated using crude and adjusted Cox proportional hazards regressions.
  
  
  RESULTS
  There were 20 056 patients in the SRR between 1991 and 2009. Of these, 579 (423 on dialysis and 156 with a renal transplant at d) incident patients with PTX were matched with 1234/892 non-PTX patients. The adjusted relative risk of death was a hazard ratio (HR) of 0.80 [95% confidence interval (CI) 0.65-0.99] for dialysis patients at d who had undergone PTX compared with matched patients who had not. Corresponding results for the patients with a renal allograft at d were an HR of 1.10 (95% CI 0.71-1.70).
  
  
  CONCLUSIONS
  PTX was associated with improved survival in patients on maintenance dialysis but not in patients with renal allograft.
authors.affiliation: Department of Nephrology, Clinical Sciences Lund, Skåne, Sweden.
authors.forename: Kerstin M
authors.initials: KM
authors.lastname: Ivarsson
authors.affiliation: Department of Nephrology and Transplantation, Skane University Hospital Lund, Skåne, Sweden.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Akaberi
authors.affiliation: VO Urology, Division 4, Malmö, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Isaksson
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Reihnér
authors.affiliation: National Registry Centre, Skane University Hospital Lund, Skåne, Sweden.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Rylance
authors.affiliation: Department of Internal Medicine, Helsingborg Hospital, Helsingborg, Sweden.
authors.forename: Karl-Göran
authors.initials: KG
authors.lastname: Prütz
authors.affiliation: Department of Nephrology and Transplantation, Skane University Hospital Lund, Skåne, Sweden.
authors.forename: Naomi
authors.initials: N
authors.lastname: Clyne
authors.affiliation: Department of Surgery Section of Endocrine and Sarcoma, Skane University Hospital, Lund, Skåne, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Almquist
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000453:epidemiology / Q000209:etiology / Q000401:mortality* / Q000601:surgery; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000601:surgery*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D016105:Parathyroidectomy / Q000401:mortality*; D016016:Proportional Hazards Models; D012042:Registries; D017582:Renal Replacement Therapy; D012307:Risk Factors; D015996:Survival Rate; D013548:Sweden
keywords: PTH; dialysis; epidemiology; hyperparathyroidism; kidney transplantation; survival analysis