title: Impact of mineral and bone disorder on healthcare resource use and associated costs in the European Fresenius medical care dialysis population: a retrospective cohort study.
abstract: BACKGROUND
  Secondary hyperparathyroidism (SHPT) is associated with mortality in patients with chronic kidney disease (CKD), but the economic consequences of SHPT have not been adequately studied in the European population. We assessed the relationship between SHPT parameters (intact parathyroid hormone [iPTH], calcium, and phosphate) and hospitalisations, medication use, and associated costs among CKD patients in Europe.
  
  
  METHODS
  The analysis of this retrospective cohort study used records of randomly selected patients who underwent haemodialysis between January 1, 2005 and December 31, 2006 at participating European Fresenius Medical Care facilities in 10 countries. Patients had ≥ 1 iPTH value recorded, and ≥ 1 month of follow-up after a 3-month baseline period during which SHPT parameters were assessed. Time at risk was post-baseline until death, successful renal transplantation, loss to follow-up, or the end of follow-up. Outcomes included cost per patient-month, rates of hospitalisations (cardiovascular disease [CVD], fractures, and parathyroidectomy [PTX]), and use of SHPT-, diabetes-, and CVD-related medications. National costs were applied to hospitalisations and medication use. Generalised linear models compared costs across strata of iPTH, total calcium, and phosphate, adjusting for baseline covariates.
  
  
  RESULTS
  There were 6369 patients included in the analysis. Mean ± SD person-time at risk was 13.1 ± 6.4 months. Patients with iPTH > 600 pg/mL had a higher hospitalisation rate than those with lower iPTH. Hospitalisation rates varied little across calcium and phosphate levels. SHPT-related medication use varied with iPTH, calcium, and phosphate. After adjusting for demographic and clinical variables, patients with baseline iPTH > 600 pg/mL had 41% (95% CI: 25%, 59%) higher monthly total healthcare costs compared with those with iPTH in the K/DOQI target range (150-300 pg/mL). Patients with baseline phosphate and total calcium levels above target ranges (1.13-1.78 mmol/L and 2.10-2.37 mmol/L, respectively) had 38% (95% CI: 27%, 50%) and 8% (95% CI: 0%, 17%) higher adjusted monthly costs, respectively. Adjusted costs were 25% (95% CI: 18%, 32%) lower among patients with baseline phosphate levels below the target range. Results were consistent in sensitivity analyses.
  
  
  CONCLUSIONS
  These data suggest that elevated SHPT parameters increase the economic burden of CKD in Europe.
authors.affiliation: Amgen (Europe) GmbH, Dammstrasse 23, 6300, Zug, Switzerland. schiroli@amgen.com
authors.forename: Silvia
authors.initials: S
authors.lastname: Chiroli
authors.forename: Caroline
authors.initials: C
authors.lastname: Mattin
authors.forename: Vasily
authors.initials: V
authors.lastname: Belozeroff
authors.forename: Louise
authors.initials: L
authors.lastname: Perrault
authors.forename: Dominic
authors.initials: D
authors.lastname: Mitchell
authors.forename: Ioanna
authors.initials: I
authors.lastname: Gioni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001862:Bone Resorption / Q000191:economics* / Q000453:epidemiology; D015331:Cohort Studies; D005060:Europe; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D015276:Health Care Rationing / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D006961:Hyperparathyroidism / Q000191:economics* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D006435:Renal Dialysis / Q000191:economics* / Q000706:statistics & numerical data; D051436:Renal Insufficiency, Chronic / Q000191:economics* / Q000453:epidemiology / Q000534:rehabilitation*; D012189:Retrospective Studies; D012307:Risk Factors; D014600:Utilization Review