title: Effect of hospital on variation in visual acuity and vision-specific quality of life after cataract surgery.
abstract: OBJECTIVE
  To evaluate the contribution of hospital-to-hospital variability in changes in clinical and health-related quality of life outcomes among patients undergoing cataract extraction by phacoemulsification.
  
  
  METHODS
  Prospective observational study of 14 public hospitals. We recruited consecutive patients on waiting lists for cataract extraction. Clinical data were collected prior to the intervention and 6 weeks afterward. Subjects completed the visual function index (VF-14) prior to the procedure and 3 months afterward. Univariate and multivariate analysis were performed for visual acuity and VF-14 scores.
  
  
  RESULTS
  Substantial differences were observed across the 14 hospitals. At baseline, mean visual acuity ranged from 0.16 to 0.34, and mean VF-14 scores ranged from 48.06 to 75.89. Following cataract extraction, the mean improvement in visual acuity ranged from 0.35 to 0.57 and in VF-14 scores from 10.94 to 41.70. The ranges were even more pronounced among patients with low visual acuity or low VF-14 scores prior to the intervention. Significant differences remained in multivariate analysis. Within the multivariate analysis, the variable 'hospitals' had an R(2) of 0.069 for the visual acuity model and of 0.073 for the VF-14 model, 20% and 13%, respectively, of the total variability explained. Variation was also observed within geographic regions.
  
  
  CONCLUSIONS
  Outcomes of patients undergoing cataract extractions vary widely from hospital to hospital, even within the same geographic region, explaining an important part of the results. Quality improvement efforts should concentrate on patients with low pre-intervention visual acuity or vision-related disability to reduce this variability in outcomes.
authors.affiliation: Unidad de Investigación, Hospital Galdakao-Usansolo-CIBER Epidemiología y Salud Pública (CIBERESP), Galdakao, Vizcaya, Spain. josemaria.quintanalopez@osakidetza.net
authors.forename: Jose M
authors.initials: JM
authors.lastname: Quintana
authors.forename: Antonio
authors.initials: A
authors.lastname: Escobar
authors.forename: Amaia
authors.initials: A
authors.lastname: Bilbao
authors.forename: Gemma
authors.initials: G
authors.lastname: Navarro
authors.forename: Jose M
authors.initials: JM
authors.lastname: Begiristain
authors.forename: Nerea
authors.initials: N
authors.lastname: Fernandez de Larrea
authors.forename: Emilio
authors.initials: E
authors.lastname: Perea
authors.forename: Txomin
authors.initials: T
authors.lastname: Alberdi
mesh_terms: D002387:Cataract Extraction; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D017063:Outcome Assessment, Health Care; D018918:Phacoemulsification; D011446:Prospective Studies; D011788:Quality of Life; D013030:Spain; D014792:Visual Acuity