title: The impact of a nationwide introduction of new drugs and a treatment protocol for glaucoma on the number of glaucoma surgeries.
abstract: OBJECTIVE
  To study the trend in number of glaucoma surgeries, and the influence hereon of the introduction of new glaucoma medication, reimbursement of its costs, and the introduction of a treatment protocol.
  
  
  METHODS
  Out of the Dutch Health Care Registration, all open angle glaucoma and ocular hypertension patients aged 20 years and older, who underwent glaucoma surgery were selected. Over the period 1995 until 2003 the trend in the number of monthly performed glaucoma surgeries was described by LOESS spline procedure.
  
  
  RESULTS
  From 1995 until 2003, 15,888 surgeries were included. Overall mean age was 67.5 years (SD 13.0). Mean age declined by 0.29 year per year (95% CI, 0.21-0.37). In 1995 and 1996 the number of yearly performed glaucoma surgeries was approximately 2400. From 1997 onwards this number started to decrease, resulting in a 45% decrease in the year 2000. From 2000 on the number of surgeries stabilized at approximately 1350 per year. In 1999 the total number of prescriptions rose by 20% compared with 1998, and then stabilized. In 2002, 48% of the prescriptions were prescriptions for new medication.
  
  
  CONCLUSIONS
  The number of glaucoma surgeries in the Netherlands almost halved over a 3.5-year period, most likely due to the introduction of new medications. In the remaining study period the number leveled off. From the present data a substitution effect and not merely a postponement of glaucoma surgeries may be suggested, providing additional evidence that a sustained reduction in the number of glaucoma surgeries was reached in the studied period.
authors.affiliation: Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Rikkert
authors.initials: R
authors.lastname: van der Valk
authors.forename: Jan S A G
authors.initials: JS
authors.lastname: Schouten
authors.forename: Carroll A B
authors.initials: CA
authors.lastname: Webers
authors.forename: Henny J M
authors.initials: HJ
authors.lastname: Beckers
authors.forename: Ludovic G P M
authors.initials: LG
authors.lastname: van Amelsvoort
authors.forename: Hubert J A
authors.initials: HJ
authors.lastname: Schouten
authors.forename: Fred
authors.initials: F
authors.lastname: Hendrikse
authors.forename: Martin H
authors.initials: MH
authors.lastname: Prins
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004363:Drug Utilization / Q000639:trends*; D005260:Female; D018463:Filtering Surgery / Q000706:statistics & numerical data / Q000639:trends*; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009798:Ocular Hypertension / Q000628:therapy
chemical_list: D000959:Antihypertensive Agents