title: External validation of existing formulas to predict the risk of developing proliferative vitreoretinopathy: the Retina 1 Project; report 5.
abstract: OBJECTIVE
  To externally validate the accuracy of previously published formulas for predicting proliferative vitreoretinopathy development after retinal detachment surgery.
  
  
  METHODS
  Clinical variables from consecutive retinal detachment patients (n = 1,047) were collected from the Retina 1 Project conducted in 17 Spanish and Portuguese centers. These data were used for external validation of four previously published formulas, F1 to F4. Receiver-operating characteristic curves were used to validate the quality of formulas, and measures of discrimination, precision, and calibration were calculated for each. Concordance among the formulas was determined by Cohen kappa index.
  
  
  RESULTS
  The areas under the receiver-operating characteristic curves were as follows: F1, 0.5809; F2, 0.5398; F3, 0.5964; and F4, 0.4617. F1 had the highest accuracy, 74.21%. Almost 19% of proliferative vitreoretinopathy cases were correctly classified by F1 compared with 13%, 15%, and 10% for F2, F3, and F4, respectively. There was moderate concordance between F2 and F3 but little between the other formulas.
  
  
  CONCLUSIONS
  After external validation, none of the formulas were accurate enough for routine clinical use. To increase its usefulness, other factors besides the clinical ones considered here should be incorporated into future formulas for predicting risk of developing proliferative vitreoretinopathy.
authors.affiliation: IOBA (Eye Institute), University of Valladolid, Valladolid, Spain. asalap@ioba.med.uva.es
authors.forename: Anna
authors.initials: A
authors.lastname: Sala-Puigdollers
authors.forename: Itziar
authors.initials: I
authors.lastname: Fernández
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Coco
authors.forename: María R
authors.initials: MR
authors.lastname: Sanabria
authors.forename: Enrique
authors.initials: E
authors.lastname: Rodríguez de la Rúa
authors.forename: José María
authors.initials: JM
authors.lastname: Ruiz-Moreno
authors.forename: Amparo
authors.initials: A
authors.lastname: Navea
authors.forename: Marta
authors.initials: M
authors.lastname: Suárez de Figueroa
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Pastor
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011183:Postoperative Complications; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012163:Retinal Detachment / Q000601:surgery*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014821:Vitrectomy / Q000009:adverse effects*; D018630:Vitreoretinopathy, Proliferative / Q000175:diagnosis* / Q000209:etiology*; D055815:Young Adult