In Reply Dr Gaynes argues that using a clinical diagnosis such as cataract as an outcome hinders the validity of our study because clinicians may differ on when to label their patients with the diagnosis. Using clinical diagnoses as outcomes is not uncommon1-3 and does not preclude a study’s validity as long as both statin users and nonusers were exposed equally to the same measure and appropriate confounders were considered.4 Our patients had similar health care coverage, were enrolled in the same regional military health care system, and were propensity score matched for inpatient and outpatient health care utilization in both baseline and follow-up periods. Additionally, we performed several analyses including a propensity score–matched cohort, a no–comorbidity index cohort (in which patients with any element of the Charlson Comorbidity Index were excluded), and 3 different subgroups of statin users based on duration of use. Our results remained consistent throughout. Therefore, our results have validity. Dr Gaynes suggests that using cataract surgery would be a more reliable outcome. We agree; however, owing to the short follow-up (approximately 4.5 years), it is unlikely that this outcome will be meaningful in our study. Longer follow-up of our cohort may enable such an assessment.
Mansi I, Leuschen J, Mortensen EM. Statins and Cataract—Reply. JAMA Ophthalmol. 2014;132(3):363. doi:10.1001/jamaophthalmol.2013.8267
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