摘要：Older adults are vastly underrepresented in clinical trials in spite of shouldering a disproportionate burden of disease and consumption of prescription drugs and therapies, restricting treatments' generalizability, efficacy, and safety. Eliminating Disparities in Clinical Trials, a national initiative comprising a stakeholder network of researchers, community advocates, policymakers, and federal representatives, undertook a critical analysis of older adults' structural barriers to clinical trial participation. We present practice and policy change recommendations emerging from this process and their rationale, which spanned multiple themes: (1) decision making with cognitively impaired patients; (2) pharmacokinetic differences and physiological age; (3) health literacy, communication, and aging; (4) geriatric training; (5) federal monitoring and accountability; (6) clinical trial costs; and (7) cumulative effects of aging and ethnicity. In the past century, tremendous strides have been made in the effective management of chronic diseases through biomedical innovations, health promotion studies, and prevention trials, along with an improved understanding of pharmaceutical treatments and genetic determinants of health. 1 However, not every population benefits equally from these advancements, and disparities are perpetuated by the low clinical trial participation of vulnerable populations. 2 – 4 Exclusion of older adults as clinical trial participants is highly problematic, because older adults suffer the greatest health burden in the Western world, enduring disproportionately high rates of cancer, 5 cardiovascular disease, 6 dementia, 7 arthritis, and Parkinson's disease. 8 They spend 36% of total US personal health care dollars 9 and consume 42% of all prescription drugs. 10 Equitable participation in clinical trials on the basis of age, then, is vital, because it can advance medical knowledge and test the safety and efficacy of new treatments that are generalizable to aging populations. 11 – 13 However, older adults continue to be underrepresented in clinical trials. 14 Although two thirds of cancer patients are older than 65 years, only about 25% of cancer trial enrollees have attained this age. 15 Further research indicates that older adults carry 60% of the national disease burden but represent only 32% of patients in phase II and III clinical trials. 16 Clinical trial participation of older adults is also low in research on Alzheimer's disease, 17 arthritis, 18 epilepsy, 19 incontinence, 20 and cardiovascular disease. 21 These failings may limit generalizability, provide insufficient data about positive or negative effects of treatment among specific populations, 3 , 13 and hinder much-needed access to new treatments. The reasons for disparate inclusion of older adults in clinical trials are complex and challenging. Typically, older adults face a combination of obstacles, including comorbidities, 4 ageism, 4 economic constraints, underinsurance, lack of insurance, 22 communication issues (e.g., hearing difficulties that interfere with telephone interviews and impaired vision that affects written surveys), 9 , 23 and physical immobility that constrains transportation options. 24 , 25 The unethical treatment of African Americans in research, epitomized by the Tuskegee Syphilis Study, 26 , 27 may partly explain why older ethnic minorities may be reluctant to participate in today's clinical trials, despite achievements in human participant protections. For example, though individuals from racial/ethnic minority groups comprise about a quarter of the US population, fewer than 1 in 10 participants in cancer studies conducted between 1995 and 1999 were from racial/ethnic minority groups. 28 We recognize that for many older members of racial/ethnic minority groups, the cumulative effect of a lifetime of poverty, racial discrimination, segregation, migration histories, and ill health creates divergent world views in older age than Whites, 29 which may fuel their mistrust in medical establishments and research. We identified policy gaps from a current and historical context, and pinpointed limitations in evidence-based knowledge and practice that may contribute to disparities in older adults' participation in clinical trials. We describe policy-oriented and practical recommendations that can be applied across all clinical trial phases and disease areas. These key areas point to several short- and long-term opportunities for recruiting and retaining older adults into clinical trials. Our findings ensued from a workgroup on aging and clinical trials under the auspices of a national initiative, Eliminating Disparities in Clinical Trials (EDICT).
