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Trial NCT00000157

Resource URI: http://static.linkedct.org/resource/trials/NCT00000157
linkedct:brief_title Randomized Trial of Aspirin and Cataracts in U.S. Physicians
linkedct:condition <http://static.linkedct.org/resource/condition/2367>
linkedct:criteria The study population consisted of 22,071 male U.S. physicians, aged 40 to 84 years in 1982, with no history of myocardial infarction, cancer, kidney disease, renal disease, or any other contraindication to the use of aspirin or beta-carotene, including regular use of corticosteroids.
linkedct:description Cataract is one of the most common causes of impaired vision as well as the third leading cause of blindness in the United States. Cataract surgery is one of the safest and most successful of all operations. The National Eye Institute has estimated that if the progression of cataract could be slowed enough to delay the need for surgery by even 10 years, the current annual number could be reduced by 45 percent. Little is known about the relative importance of various potential risk factors in the development of cataract. Most current information on risk factors has come from anecdotal reports or from relatively small case-control studies. One major project, the Framingham Eye Study, has identified several factors that were significantly associated with subsequent cataract formation, including diabetes and dietary factors. Diabetes has long been thought to increase the risk of developing cataract. Recently, aspirin has been proposed as a drug that can prevent cataract formation or slow its progression. Aspirin may affect tryptophan levels in patients with cataract, or it may inhibit aldose reductase, an enzyme associated with the development of diabetic cataract. Thus, data from this study sought to determine whether one 325-mg aspirin tablet, taken on alternate days, protects against cataract formation. The data also sought to reveal other additional cataract risk factors that emerge after simultaneous controlling for other variables. The other primary objective of this trial was to assess the antioxidant effects of beta-carotene (50 mg on alternate days) on cataract development. In addition, factors that have been suggested to be cataractogenic were assessed in prospective cohort studies. These factors included age, blood pressure, blood cholesterol, height, diabetes, medication use, cigarette smoking, and history of previous eye trauma or surgery. In addition, the possible associations between history of vitamin E and selenium intake and cataract were explored. This trial was part of the Physicians Health Study, an ongoing, randomized, placebo-controlled clinical trial of aspirin in the prevention of cardiovascular mortality and of beta-carotene in the prevention of cancer. Following randomization, each of the 22,071 physicians enrolled was assigned to one of four groups to take either aspirin or its placebo and beta-carotene or its placebo. Follow-up questionnaires were sent 6 and 12 months after randomization and every 12 months thereafter. The randomized aspirin component of the trial was terminated early (January 1988), after an average followup of approximately 5 years, because of a statistically extreme 44 percent reduced risk of a first myocardial infarction in the aspirin group. Since this study is conducted by mail among physicians nationwide, examinations cannot be performed on all patients to determine when they have reached an end point. Reported diagnoses of cataract are confirmed by medical record review. The primary analysis will be of incidence of cataract in the aspirin and placebo groups. In addition, the Cox proportional hazards model will be used to determine whether there is a difference in time to cataract diagnosis between the two groups. It has been postulated that the potent antioxidant properties of beta-carotene might make it effective in preventing cataract development. The investigators will thus determine whether there is a difference in the numbers of cataracts between the beta-carotene/placebo groups and the aspirin/placebo groups.
linkedct:download_date Information obtained from ClinicalTrials.gov on December 30, 2009
linkedct:eligibility_gender Male
linkedct:eligibility_healthy_volunteers Accepts Healthy Volunteers
linkedct:eligibility_maximum_age 84 Years
linkedct:eligibility_minimum_age 40 Years
linkedct:end_date January 1988
linkedct:enrollment 0 (xsd:int)
linkedct:firstreceived_date September 23, 1999
linkedct:id NCT00000157
rdfs:label Trial NCT00000157
linkedct:lastchanged_date September 16, 2009
linkedct:lead_sponsor_agency National Eye Institute (NEI)
linkedct:nct_id NCT00000157
linkedct:number_of_arms 0 (xsd:int)
linkedct:number_of_groups 0 (xsd:int)
linkedct:org_study_id NEI-59
linkedct:overall_status Terminated
linkedct:oversight <http://static.linkedct.org/resource/oversight/2918>
foaf:page <http://clinicaltrials.gov/show/NCT00000157>
linkedct:phase Phase 3
linkedct:reference <http://static.linkedct.org/resource/reference/21402>
linkedct:reference <http://static.linkedct.org/resource/reference/37818>
linkedct:reference <http://static.linkedct.org/resource/reference/45619>
linkedct:reference <http://static.linkedct.org/resource/reference/46712>
linkedct:reference <http://static.linkedct.org/resource/reference/47801>
linkedct:reference <http://static.linkedct.org/resource/reference/50508>
linkedct:source National Eye Institute (NEI)
linkedct:start_date April 1982
linkedct:study_design Prevention, Randomized, Placebo Control
linkedct:study_type Interventional
linkedct:summary To determine whether 325 mg of aspirin taken on -alternate days reduces the risk of developing cataract among male U.S. physicians who were aged 40 to 84 in 1982. To identify potential risk factors for cataract development, such as age, blood pressure, blood cholesterol, height, diabetes, medication use, and history of previous eye trauma or surgery.
rdf:type linkedct:trials
linkedct:verification_date September 2009