Participation in the Ischemic Optic Neuropathy Decompression Trial: Sex, race, and age

BACKGROUND. The Ischemic Optic Neuropathy Decompression Trial (IONDT) is a randomized, single masked, multicenter trial designed to assess the safety and efficacy of optic nerve decompression surgery compared with careful follow-up in patients 50 years or older with non-arteritic anterior ischemic neuropathy (NAION). OBJECTIVES. To examine and evaluate the sex, race, and age distributions of the screened, and subsequently enrolled, IONDT population, especially the proportions of female, minority, and elderly patients, and demographic characteristics of clinical center investigators, the geographical location of IONDT Clinical Centers, and the referral patterns of local physicians. SETTING. Twenty-five U.S. clinical centers. PARTICIPANTS. There were 1681 referrals to the Clinical Centers; an Eligibility Screening Form providing demographic information was completed for 1152. FINDINGS. Forty-three percent (495/1152) of screened cases were women. Seven percent (85/1152) were minorities: 33 African-Americans, 34 Hispanics, 17 Asians, and 1 Native-American. The average age was 66 ± 10 years with a range of 22-92 years of age. Of the 1152 referred patients, 305 were eligible for randomization; 258 (85%) of these agreed to participate in the trial. The demographic makeup of the randomized IONDT patients was similar to that of the screened population. CONCLUSIONS. Women and the elderly are well represented in the IONDT. Because the number of participating minorities was low, we cannot reliably assess their level of participation. Both a low incidence of NAION in minorities and a low referral rate of minorities to clinical trials are plausible explanations for our findings.