title: Development and validation of a predictive model for nonadherence with once-daily glaucoma medications.
abstract: OBJECTIVE
  To develop and validate a predictive model to estimate the probability of being nonadherent to topical glaucoma medications.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Patients being treated with once-daily prostaglandin eye drops.
  
  
  METHODS
  A predictive model for nonadherence was developed from the Travatan Dosing Aid (TDA) study (n = 196) using stepwise logistic regression. The performance of the TDA-derived model was assessed using a separate cohort of subjects from the Automated Dosing Reminder Study (ADRS; n = 407). The assessment was based on regression coefficients, discrimination, and calibration. We also developed a scoring system from the TDA-derived model to simplify the estimation of risk for clinical use.
  
  
  METHODS
  Usage of drops was monitored electronically for 3 months in both studies. Adherence was calculated as the percentage of days on which a dose was taken within 4 hours of the average dosing time for that patient. Nonadherence was defined as taking ≤ 75% prescribed doses within a window starting 2 weeks after the baseline visit until 2 weeks before the follow-up visit.
  
  
  RESULTS
  Six factors, including younger age, black race, worse general health status, shorter duration of glaucoma medication therapy, lower self-reported adherence, and admitting to not following doctors' orders, were associated with being nonadherent and were included in the predictive model. The coefficients for the TDA-derived and the ADRS-derived predictive models were similar. The risk scoring system developed from the TDA study had good discrimination (area under the receiver operating characteristic curve of 0.80) and calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.102) when applied to the ADRS population.
  
  
  CONCLUSIONS
  The TDA-derived predictive model for nonadherence performed well in an independent population. A risk scoring system was developed using demographic data and patient responses to 4 questions to provide an estimate of the probability of being nonadherent.
authors.affiliation: Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Dolly S
authors.initials: DS
authors.lastname: Chang
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.forename: Travis
authors.initials: T
authors.lastname: Frazier
authors.forename: Ryan
authors.initials: R
authors.lastname: Plyler
authors.forename: Michael V
authors.initials: MV
authors.lastname: Boland
mesh_terms: D000287:Administration, Topical; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D003008:Cloprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives; D015331:Cohort Studies; D016903:Drug Monitoring; D005260:Female; D005901:Glaucoma / Q000145:classification / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D011336:Probability; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D000069557:Travoprost
chemical_list: D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D003008:Cloprostenol; D000069557:Travoprost
references.citation: Clin Ther. 2009 Oct;31(10):2178-88; discussion 2150-1
references.pmid: 19922889
references.citation: Am J Epidemiol. 1984 Jun;119(6):997-1004
references.pmid: 6731436
references.citation: Arch Ophthalmol. 2005 Oct;123(10):1351-60
references.pmid: 16219726
references.citation: Ophthalmology. 2008 Aug;115(8):1320-7, 1327.e1-3
references.pmid: 18321582
references.citation: Ophthalmology. 2005 Jun;112(6):953-61
references.pmid: 15885795
references.citation: Ophthalmology. 2009 Dec;116(12):2286-93
references.pmid: 19815286
references.citation: Am J Ophthalmol. 1986 May 15;101(5):524-30
references.pmid: 3706456
references.citation: J Glaucoma. 2009 Mar;18(3):238-43
references.pmid: 19295380
references.citation: Invest Ophthalmol Vis Sci. 2007 Nov;48(11):5052-7
references.pmid: 17962457
references.citation: Ophthalmology. 2009 Feb;116(2):191-9
references.pmid: 19084273
references.citation: J Glaucoma. 2012 Apr-May;21(4):234-40
references.pmid: 21623223
references.citation: J Glaucoma. 2011 Sep;20(7):414-21
references.pmid: 21048510
references.citation: Am J Ophthalmol. 1986 May 15;101(5):515-23
references.pmid: 3706455
references.citation: J Manag Care Pharm. 2008 Jul-Aug;14(6):553-60
references.pmid: 18693779
references.citation: Ophthalmology. 2011 Dec;118(12):2398-402
references.pmid: 21856009
references.citation: Ophthalmology. 2009 Jun;116(6):1097-105
references.pmid: 19376591
references.citation: Can J Ophthalmol. 2008 Aug;43(4):454-61
references.pmid: 18711461
references.citation: Ophthalmology. 2006 Mar;113(3):431-6
references.pmid: 16458967