Purchase this article with an account.
J. H. Kempen, C. S. Foster, K. J. Helzlsouer, D. A. Jabs, G. A. Levy-Clarke, R. B. Nussenblatt, J. T. Rosenbaum, E. B. Suhler, Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study Group; Epidemiologic Methods for Detecting Rare, Long-Term Adverse Events Associated With Eye Diseases: The Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study. Invest. Ophthalmol. Vis. Sci. 2007;48(13):4408.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To describe epidemiological methods for evaluating putative long-term effects of systemic immunosuppressive therapies on the risk of mortality and cancer, and present the approach of the SITE Cohort Study.
Prospective individual-level studies, ideally with randomization, provide the most robust data regarding "effects" of treatments on outcomes, but are very costly and take many years to reach useful conclusions. Retrospective cohort studies, while more efficient in cost and timeliness, are completely dependent on the fortuitous availability of existing records which provide quality information over as much follow-up time as would be required for a prospective study. Case-control methods would require very large sample sizes to study the association of common outcomes (e.g., mortality) and rare exposures (e.g., treatment of eye diseases with immunosuppressive medicines), and incur problems of using surrogate reporting for the (dead) cases but not for controls.
The SITE Cohort Study is a retrospective cohort study, ascertaining use/non-use of immunosuppressive medications from existing medical records of ~9,263 ocular inflammatory disease patients at five centers. Mortality and cause-specific mortality data are obtained through the National Death Index, a national registry of death certificates, providing ~101,680 person-years of follow-up. United States vital statistics provide general population mortality rates for comparison with treated and non-treated ocular inflammation patients. Calculated (2-tailed) detectable differences in the risk of mortality and of fatal malignancy respectively with respect to the general population for classes of agents are: 22% and 49% for antimetabolites; 28% and 62% for T-cell inhibitors; and 36% and 81% for alkylating agents.
The SITE Cohort Study is expected to provide valuable information regarding important uncertainties about putative long-term adverse effects of immunosuppressive agents used in managing eye diseases.
This PDF is available to Subscribers Only