Gerontologic Biostatistics: The Statistical Challenges of Clinical Research with Older Study Participants

Abstract

The medical and personal circumstances of older persons present challenges for designing and analyzing clinical research studies in which they participate. These challenges presented by elderly study samples are not unique but they are sufficiently distinctive to warrant deliberate and systematic attention. Their distinctiveness originates in the multifactorial etiologies of geriatric health syndromes and the multiple morbidities accruing with aging at the end of life. The objective of this article is to identify a set of statistical challenges arising in research with older persons that should be considered conjointly in the practice of clinical research and that should be addressed systematically in the training of biostatisticians intending to work with gerontologists, geriatricians, and older study participants. The statistical challenges include design and analytical strategies for multicomponent interventions, multiple outcomes, state transition models, floor and ceiling effects, missing data, and mixed methods. The methodological and pedagogical themes of this article will be integrated by a description of a proposed subdiscipline of "gerontologic biostatistics" and supported by the introduction of new set of statistical resources for researchers working in this area. These conceptual and methodological resources have been developed in the context of several collaborating Claude D. Pepper Older Americans Independence Centers.

Efficacy and effectiveness as aspects of cluster randomized trials with nursing home residents: Methodological insights from a pneumonia prevention trial

“…Clustered designs offer one approach, involving characteristic opportunities and constraints. Geriatric and gerontologic researchers have considerable experience and expertise working with older study participants and grappling with the distinctive clinical [21] and statistical [26] challenges they pose. The PRIDE trial is contributing to current efforts to advance comparative effectiveness research among nursing home residents.…”

Mixed Methods for the Interpretation of Longitudinal Gerontologic Data

“…Clinical attention in geriatric care is not restricted to medical cures—though they are highly desirable to achieve when possible—but is also consistently directed to quality of life and integrity of medical decision making. Because these issues involve deeply personal and individualistic elements, clinical aging research is an especially appropriate context for measuring health outcomes qualitatively as they change over time (Van Ness et al, 2010). …”

The stress of aging

“…This will facilitate the building of evidence specific for frail older persons and provide research results of easier and quicker implementation to the clinical setting. For example, several trials have already been increasingly implementing multidomain interventions against major geriatric conditions (including physical disability (Opasich et al, 2010;van Hout et al, 2010), Alzheimer's disease (Gillette Guyonnet et al, 2008;Nourhashemi et al, 2010), and falls (Vind et al, 2010)), often adopting standardly-tailored designs (Van Ness et al, 2010). In this context, about one year ago, we started at the Centre Hospitalier Universitaire de Toulouse (Toulouse, France), a novel and innovative clinical setting aimed at evaluating frail non-disabled older persons living in the community.…”