TY - JOUR
T1 - Interobserver reliability of the prism and alternate cover test in children with esotropia
AU - Holmes, Jonathan M.
AU - Chandler, Danielle L.
AU - Christiansen, Stephen P.
AU - Birch, Eileen E.
AU - Bothun, Erick
AU - Laby, Daniel
AU - Melia, B. Michele
AU - Repka, Michael X.
AU - Silbert, David I.
AU - Zeto, V. Lori
PY - 2009/1
Y1 - 2009/1
N2 - Objective: To determine 95% limits of agreement on a measurement and on a difference between 2 measurements for the prism and alternate cover test (PACT) at distance and at near fixation. Methods: In a test-retest reliability study, 143 children aged 60 months or younger with esotropia were examined by 2 masked examiners on 1 or 2 occasions yielding 199 test-retest pairs for PACT at distance fixation and 239 test-retest pairs for PACT at near fixation. Results: For angles greater than 20 prism diopters (PD), the 95% limits of agreement on a measurement and on a difference between 2 measurements were ±7.3 PD and ±10.4 PD, respectively, for PACT at distance and ±8.3 PD and ±11.7 PD, respectively, for PACT at near. For angles of 10 to 20 PD, the 95% limits of agreement on a measurement and on a difference between 2 measurements were ±4.1 PD and ±5.8 PD, respectively, for PACT at distance and ±3.3 PD and ±4.7 PD, respectively, for PACT at near. Conclusion: In childhood esotropia, differences of 12 PD or more for angles greater than 20 PD and differences of 6 PD or more for angles between 10 PD and 20 PD are likely to indicate real change. Smaller differences could be real change but could also be due to measurement error.
AB - Objective: To determine 95% limits of agreement on a measurement and on a difference between 2 measurements for the prism and alternate cover test (PACT) at distance and at near fixation. Methods: In a test-retest reliability study, 143 children aged 60 months or younger with esotropia were examined by 2 masked examiners on 1 or 2 occasions yielding 199 test-retest pairs for PACT at distance fixation and 239 test-retest pairs for PACT at near fixation. Results: For angles greater than 20 prism diopters (PD), the 95% limits of agreement on a measurement and on a difference between 2 measurements were ±7.3 PD and ±10.4 PD, respectively, for PACT at distance and ±8.3 PD and ±11.7 PD, respectively, for PACT at near. For angles of 10 to 20 PD, the 95% limits of agreement on a measurement and on a difference between 2 measurements were ±4.1 PD and ±5.8 PD, respectively, for PACT at distance and ±3.3 PD and ±4.7 PD, respectively, for PACT at near. Conclusion: In childhood esotropia, differences of 12 PD or more for angles greater than 20 PD and differences of 6 PD or more for angles between 10 PD and 20 PD are likely to indicate real change. Smaller differences could be real change but could also be due to measurement error.
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U2 - 10.1001/archophthalmol.2008.548
DO - 10.1001/archophthalmol.2008.548
M3 - Article
C2 - 19139339
AN - SCOPUS:58449101069
SN - 0003-9950
VL - 127
SP - 59
EP - 65
JO - Archives of ophthalmology
JF - Archives of ophthalmology
IS - 1
ER -