Statistical techniques in ophthalmic journals

Over the years, the use of statistics to evaluate experimental data in ophthalmology has increased. The present study sought to assess the frequency and types of statistical techniques used in ophthalmic journals. We reviewed 974 original articles from the Archives for 1970, 1980, and 1990; the American Journal of Ophthalmology for 1990; and Ophthalmology for 1990. Of the 592 articles reviewed for 1990, 391 (66.0%) contained statistics, with measures of central tendency most commonly used (385 articles [65.0%]), followed by dispersion (298 [50.3%]), t test (120 [20.3%]), and contingency tables (98 [16.6%]). A reader familiar with 10 statistical techniques would have "statistical accessibility" to 526 (88.9%) of 1990 articles. A statistically significant difference was found in the percentage of articles containing statistical methods among the journals (P = .0003; Archives, 75.3%; Ophthalmology, 66.8%; and American Journal of Ophthalmology, 55.2%).