title: Changing treatments for primary urolithiasis: impact on services and renal preservation in 16,679 patients in Western Australia.
abstract: OBJECTIVE
  To examine changing treatments for the primary presentation of urinary lithiasis and their effects on re-admissions, repeat procedures, cumulative hospital use and renal preservation.
  
  
  METHODS
  Linked hospital morbidity records were used to identify first-time admissions for renal and ureteric calculi from 1980 to 1997 in the population of Western Australia. The cases were followed to mid-1999 and actuarial methods used to estimate risks of further hospital admissions and procedures, including the loss of a renal moiety.
  
  
  RESULTS
  Between 1980 and 1997 the total rate of inpatient procedures for urinary stones more than doubled, at a time when the rate of first-time hospital admissions increased by only 13% and the conservative management of stones remained constant at approximately 59%. The predominant procedure for stone management was initially open lithotomy, replaced in the early 1980s by percutaneous nephrolithotomy and soon supplemented by extracorporeal shock wave lithotripsy (ESWL). The changes in technology led to a four-fold increase in procedural re-admissions within 30 days of primary separation. This was a result of repeated, staged or postponed interventions, often involving the use of stents or a second treatment with ESWL. The risk of surgical intervention decreased from 48% to 32%, whilst the cumulative length of stay over the first year decreased from 7.8 to 3.9 days. The risk of kidney loss declined significantly from 2% to <0.1% during the period.
  
  
  CONCLUSIONS
  The main reason for more interventions were short-term procedural re-admissions. ESWL reduced the need for invasive procedures and decreased cumulative hospital stay, despite more re-admissions. Renal preservation improved by a factor of 10.
authors.affiliation: Department of Public Health, The University Western Australia, Nedlands, Australia.
authors.forename: C D J
authors.initials: CD
authors.lastname: Holman
authors.forename: Z S
authors.initials: ZS
authors.lastname: Wisniewski
authors.forename: J B
authors.initials: JB
authors.lastname: Semmens
authors.forename: A J
authors.initials: AJ
authors.lastname: Bass
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007669:Kidney Calculi / Q000453:epidemiology / Q000628:therapy; D008096:Lithotripsy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods; D010359:Patient Readmission / Q000706:statistics & numerical data; D012008:Recurrence; D015607:Stents; D014514:Ureteral Calculi / Q000453:epidemiology / Q000628:therapy; D014545:Urinary Calculi / Q000628:therapy*; D014904:Western Australia / Q000453:epidemiology