TY - JOUR
T1 - External validation of the OHTS-EGPS model for predicting the 5-year risk of open-angle glaucoma in ocular hypertensives
AU - Takwoingi, Yemisi
AU - Botello, Adriana P
AU - Burr, Jennifer M
AU - Azuara-Blanco, Augusto
AU - Garway-Heath, David F
AU - Lemij, Hans G
AU - Sanders, Roshini
AU - King, Anthony J
AU - Deeks, Jonathan J
AU - Surveillance for Ocular Hypertension Study Group
AU - Takwoingi, Yemisi
PY - 2014/3
Y1 - 2014/3
N2 - AIMS: To independently evaluate and compare the performance of the Ocular Hypertension Treatment Study-European Glaucoma Prevention Study (OHTS-EGPS) prediction equation for estimating the 5-year risk of open-angle glaucoma (OAG) in four cohorts of adults with ocular hypertension.METHODS: Data from two randomised controlled trials and two observational studies were analysed individually to assess transferability of the prediction equation between different geographical locations and settings. To make best use of the data and to avoid bias, missing predictor values were imputed using multivariate imputation by chained equations. Using the OHTS-EGPS risk prediction equation, predicted risk was calculated for each patient in each cohort. We used the c-index, calibration plot and calibration slope to evaluate predictive ability of the equation.RESULTS: Analyses were based on 393, 298, 188 and 159 patients for the Rotterdam, Moorfields, Dunfermline, and Nottingham cohorts, respectively. The discriminative ability was good, with c-indices between 0.69 and 0.83. In calibration analyses, the risk of OAG was generally overestimated, although for the Rotterdam cohort the calibration slope was close to 1 (1.09, 95% CI 0.72 to 1.46), the ideal value when there is perfect agreement between predicted and observed risks.CONCLUSIONS: The OHTS-EGPS risk prediction equation has predictive utility, but further validation in a population-based setting is needed.
AB - AIMS: To independently evaluate and compare the performance of the Ocular Hypertension Treatment Study-European Glaucoma Prevention Study (OHTS-EGPS) prediction equation for estimating the 5-year risk of open-angle glaucoma (OAG) in four cohorts of adults with ocular hypertension.METHODS: Data from two randomised controlled trials and two observational studies were analysed individually to assess transferability of the prediction equation between different geographical locations and settings. To make best use of the data and to avoid bias, missing predictor values were imputed using multivariate imputation by chained equations. Using the OHTS-EGPS risk prediction equation, predicted risk was calculated for each patient in each cohort. We used the c-index, calibration plot and calibration slope to evaluate predictive ability of the equation.RESULTS: Analyses were based on 393, 298, 188 and 159 patients for the Rotterdam, Moorfields, Dunfermline, and Nottingham cohorts, respectively. The discriminative ability was good, with c-indices between 0.69 and 0.83. In calibration analyses, the risk of OAG was generally overestimated, although for the Rotterdam cohort the calibration slope was close to 1 (1.09, 95% CI 0.72 to 1.46), the ideal value when there is perfect agreement between predicted and observed risks.CONCLUSIONS: The OHTS-EGPS risk prediction equation has predictive utility, but further validation in a population-based setting is needed.
KW - Antihypertensive Agents
KW - Female
KW - Glaucoma, Open-Angle
KW - Humans
KW - Intraocular Pressure
KW - Male
KW - Middle Aged
KW - Observational Study as Topic
KW - Ocular Hypertension
KW - Proportional Hazards Models
KW - Randomized Controlled Trials as Topic
KW - Risk Assessment
KW - Risk Factors
KW - Tonometry, Ocular
U2 - 10.1136/bjophthalmol-2013-303622
DO - 10.1136/bjophthalmol-2013-303622
M3 - Article
C2 - 24357494
SN - 0007-1161
VL - 98
SP - 309
EP - 314
JO - British Journal of Ophthalmology
JF - British Journal of Ophthalmology
IS - 3
ER -