Original articleChoice of Analytic Approach for Eye-Specific Outcomes: One Eye or Two?
Section snippets
Selection and Categorization of Articles
An ophthalmologist (M.T.) selected 2 general and 3 subspecialty ophthalmology journals from the top 50% of the list of 45 ophthalmology journals on the ISI Web of Knowledge (ranked according to their 2007 impact factor). Both general and subspecialty ophthalmology journals were selected to reflect the broad spectrum and the distribution of analytic approaches in these published ophthalmologic articles. The journals selected were Acta Ophthalmologica, the American Journal of Ophthalmology, the
Review of Original Articles
In total, 161 original articles published in 2008 were reviewed. Of these, 31 articles were excluded from further analysis because no statistical inferential techniques were used (19.3%). One hundred eighteen (73.3%) of the remaining 130 articles that described the results of clinical or epidemiologic human investigations were considered further. The other 12 studies comprised 7 animal experiments, 3 laboratory studies, an article assessing the flow rate of vitreous cutters in different
Discussion
The findings of the present review indicate that interocular correlation is not assessed frequently or exploited in clinical ophthalmologic studies and that violation of the statistical assumption of independence remains fairly common practice. Although the issue of correlated data in ophthalmic research repeatedly has been raised in the literature, in the present study, it was found that interocular correlation was mentioned, assessed, or adjusted for in a small proportion of the articles in
References (39)
The importance of accounting for correlated observations
PM R
(2010)- et al.
Photopic pupillometry-guided laser in situ keratomileusis of hyperopic presbyopia
J Cataract Refract Surg
(2008) - et al.
Testing the equality of proportions for correlated otolaryngologic data
Comput Stat Data Anal
(2008) Statistical methods in ophthalmology: an adjustment for the intraclass correlation between eyes
Biometrics
(1982)- et al.
Incorporation of clustering effects for the Wilcoxon rank sum test: a large-sample approach
Biometrics
(2003) - et al.
Extending the simple linear regression model to account for correlated responses: an introduction to generalized estimating equations and multi-level modelling
Stat Med
(1998) - et al.
Appropriate statistical methods to account for similarities in binary outcomes between fellow eyes
Invest Ophthalmol Vis Sci
(1994) - et al.
Perimetry and migraine-deficits may not implicate glaucoma
Graefes Arch Clin Exp Ophthalmol
(2006) Photocoagulation treatment of proliferative diabetic retinopathy: the second report from the Diabetic Retinopathy Study
Arch Ophthalmol
(1978)- et al.
The Glaucoma Laser Trial: IAcute effects of argon laser trabeculectomy on intraocular pressure
Arch Ophthalmol
(1989)
Eyes or patients?Traps for the unwary in the statistical analysis of ophthalmological studies
Br J Ophthalmol
People and eyes: statistical approaches in ophthalmology
Br J Ophthalmol
Multilevel Statistical Models
Applied Mixed Models in Medicine
CONSORT statement: extension to cluster randomized trials
Br Med J
Statistical methods in ophthalmology: an adjusted chi-square approach
Biometrics
Comparison of alternative regression models for paired binary data
Stat Med
Accounting for the correlation between fellow eyes in regression analysis
Arch Ophthalmol
Methods to quantify the relation between disease progression in paired eyes
Am J Epidemiol
Cited by (0)
Supplemental Material available at AJO.com.