Models and Studies of Aging: Executive Summary of a Report from the U13 Conference Series

Patient-reported outcome measure use among older adults after emergency department care: A systematic review

BACKGROUND

Patient-reported outcome measures (PROMs) are gaining favor in clinical and research settings given their ability to capture a patient's symptom burden, functional status, and quality of life. Our objective in this systematic review was to summarize studies including PROMs assessed among older adults (age ≥ 65 years) after seeking emergency care.

METHODS

With the assistance of a medical librarian, we searched Ovid MEDLINE, PubMed, Embase, CINAHL, Web of Science-Core Collection, and Cochrane CENTRAL from inception through June 2023 for studies in which older adult ED patients had PROMs assessed in the post-emergency care time period. Independent reviewers performed title/abstract review, full-text screening, data extraction, study characteristic summarization, and risk-of-bias (RoB) assessments.

RESULTS

Our search strategy yielded 5153 studies of which 56 met study inclusion criteria. Within included studies, 304 unique PROM assessments were performed at varying time points after the ED visit, including 61 unique PROMs. The most commonly measured domain was physical function, assessed within the majority of studies (47/56; 84%), with measures including PROMs such as Katz activities of daily living (ADLs), instrumental ADLs, and the Barthel Index. PROMs were most frequently assessed at 1-3 months after an ED visit (113/304; 37%), greater than 6 months (91/304; 30%), and 4-6 months (88/304; 29%), with very few PROMs assessed within 1 month of the ED visit (12/304; 4%). Of the 16 interventional studies, two were determined to have a low RoB, four had moderate RoB, nine had high RoB, and one had insufficient information. Of the 40 observational studies, 10 were determined to be of good quality, 20 of moderate quality, and 10 of poor quality.

CONCLUSIONS

PROM assessments among older adults following an ED visit frequently measured physical function, with very few assessments occurring within the first 1 month after an ED visit.

A time-series analysis of blood-based biomarkers within a 25-year longitudinal dolphin cohort

Causal interactions and correlations between clinically-relevant biomarkers are important to understand, both for informing potential medical interventions as well as predicting the likely health trajectory of any individual as they age. These interactions and correlations can be hard to establish in humans, due to the difficulties of routine sampling and controlling for individual differences (e.g., diet, socio-economic status, medication). Because bottlenose dolphins are long-lived mammals that exhibit several age-related phenomena similar to humans, we analyzed data from a well controlled 25-year longitudinal cohort of 144 dolphins. The data from this study has been reported on earlier, and consists of 44 clinically relevant biomarkers. This time-series data exhibits three starkly different influences: (A) directed interactions between biomarkers, (B) sources of biological variation that can either correlate or decorrelate different biomarkers, and (C) random observation-noise which combines measurement error and very rapid fluctuations in the dolphin's biomarkers. Importantly, the sources of biological variation (type-B) are large in magnitude, often comparable to the observation errors (type-C) and larger than the effect of the directed interactions (type-A). Attempting to recover the type-A interactions without accounting for the type-B and type-C variation can result in an abundance of false-positives and false-negatives. Using a generalized regression which fits the longitudinal data with a linear model accounting for all three influences, we demonstrate that the dolphins exhibit many significant directed interactions (type-A), as well as strong correlated variation (type-B), between several pairs of biomarkers. Moreover, many of these interactions are associated with advanced age, suggesting that these interactions can be monitored and/or targeted to predict and potentially affect aging.

Study of Longitudinal Aging in Mice: Presentation of Experimental Techniques

Aging is associated with functional and metabolic decline and is a risk factor for all noncommunicable diseases. Even though mice are routinely used for modeling human aging and aging-related conditions, no comprehensive assessment to date has been conducted on normative mouse aging. To address this gap, the Study of Longitudinal Aging in Mice (SLAM) was designed and implemented by the National Institute on Aging (NIA/NIH) as the mouse counterpart to the Baltimore Longitudinal Study of Aging (BLSA). In this manuscript, we describe the premise, study design, methodologies, and technologies currently employed in SLAM. We also discuss current and future study directions. In this large population mouse study, inbred C57BL/6J and outbred UM-HET3 mice of both sexes are longitudinally evaluated for functional, phenotypic, and biological health, and collection of biospecimens is conducted throughout their life span. Within the longitudinal cohorts, a cross-sectional arm of the study has also been implemented for the well-controlled collection of tissues to generate a biorepository. SLAM and studies stemming from SLAM seek to identify and characterize phenotypic and biological predictors of mouse aging and age-associated conditions, examine the degrees of functional and biomolecular variability that occur within inbred and genetically heterogeneous mouse populations with age, and assess whether these changes are consistent with alterations observed in human aging in BLSA. The findings from these studies will be critical for evaluating the utility of mouse models for studying different aspects of aging, both in terms of interpreting prior findings and designing and implementing future studies.

Knowledge and clinical dialogues about complementary health approaches among nurse practitioners specialized in geriatrics

BACKGROUND

In the United States, people over the age of 65 years will account for 20% of the population by 2030, and these elders are more likely to have chronic comorbid complex health problems. Sixty-three percent use complementary health approaches (CHAs) but less than half disclose their use to their health care providers. Nurse practitioners (NPs) are the fastest growing population of primary care health providers.

PURPOSE

This study identifies to what degree NPs with specialized training in geriatrics understand CHAs, use them themselves, encourage their patients to access them, and engage in CHA clinical dialogue.

METHODS

Cross-sectional online survey collecting quantitative and narrative data; US NPs with specialized training in geriatrics (n = 170, mean age 52 years, SD: 9.0, range: 29-73).

RESULTS

Although NPs are knowledgeable about some CHA and believe they are beneficial for older adults to use, they want more education to help understand the effects of a variety of CHA, be more aware of possible treatment interactions, and to integrate CHA into the current health care system. Patient factors (impaired cognitive function, acute health problems, and not open to CHA), provider factors (inadequate CHA knowledge, limited referral paths and resources), and system factors (limited accessibility and availability of CHA in in-patient setting, CHA not covered by insurance, and limited clinical time) disrupt NPs from assessing and discussing CHA with their patients.

IMPLICATIONS FOR PRACTICE

There is a need to develop and implement NP practice guidelines for CHA clinical management for older adults and provide educational opportunities to incorporate CHA into clinical practice.

A 25-y longitudinal dolphin cohort supports that long-lived individuals in same environment exhibit variation in aging rates

Aging is a degradative process that varies among individuals. Due to limitations in defining and differentiating aging rates in human populations, understanding why some people appear to age slower than others has proven difficult. We analyzed 44 blood-based indices of health as candidate aging rate biomarkers collected over a 25-y period on a relevant, long-lived population of dolphins. Evidence of subsets of dolphins exhibiting slow and accelerated aging rates were detected, despite sharing the same environment, diet, and health care. Furthermore, some dolphin subsets were more likely to develop clinically relevant conditions, including anemia and immunosenescence. Our results support the notion that aging rates in long-lived mammals may be defined and provide insight into novel interventions to delay aging.

While it is believed that humans age at different rates, a lack of robust longitudinal human studies using consensus biomarkers meant to capture aging rates has hindered an understanding of the degree to which individuals vary in their rates of aging. Because bottlenose dolphins are long-lived mammals that develop comorbidities of aging similar to humans, we analyzed data from a well-controlled, 25-y longitudinal cohort of 144 US Navy dolphins housed in the same oceanic environment. Our analysis focused on 44 clinically relevant hematologic and clinical chemistry measures recorded during routine blood draws throughout the dolphins’ lifetimes. Using stepwise regression and general linear models that accommodate correlations between measures obtained on individual dolphins, we demonstrate that, in a manner similar to humans, dolphins exhibit independent and linear age-related declines in four of these measures: hemoglobin, alkaline phosphatase, platelets, and lymphocytes. Using linear regressions and analyses of covariance with post hoc Tukey–Kramer tests to compare slopes (i.e., linear age-related rates) of our four aging rate biomarkers among 34 individual dolphins aging from 10 y to up to 40 y old, we could identify slow and accelerated agers and differentiate subgroups that were more or less likely to develop anemia and lymphopenia. This study successfully documents aging rate differences over the lifetime of long-lived individuals in a controlled environment. Our study suggests that nonenvironmental factors influencing aging rate biomarkers, including declining hemoglobin and anemia, may be targeted to delay the effects of aging in a compelling model of human biology.

Current nutritional and pharmacological anti-aging interventions

Aging is the main risk factor for chronic diseases and disablement in human societies with a great impact in social and health care expenditures. So far, aging and, eventually, death are unavoidable. Nevertheless, research efforts on aging-associated diseases with the aim not only to extend life span but also to increment health span in an attempt to delay, stop and even reverse the aging process have not stopped growing. Caloric restriction extends both health and life span in several short-lived experimental models and has brought to light the role of different molecular effectors involved in nutrient sensing pathways and longevity. This opens the possibility of modulating these molecular effectors also in humans to increase longevity and health span. The difficulty to implement caloric restricted diets in humans has led to the development of new bearable diets such as time-restricted feeding, intermittent fasting or diets with limited amounts of some nutrients and to the search of pharmacological agents, targeted to the effectors that mediate the extension of life and health span in response to these anti-aging diets. Pharmacological approaches that eliminate senescent cells or prevent primary causes of aging such as telomere attrition also emerge as potential anti-aging strategies. In the present article, we review these possible nutritional and pharmacological interventions designed to mitigate and/or delay the aging process and to increase health and life span.

Leadership Lessons: Developing Mentoring Infrastructure for GEMSSTAR Scholars

Through the National Institute on Aging's (NIA's) "Grants for Early Medical/Surgical Specialists" Transition to Aging Research (GEMSSTAR) U13 grant, the NIA and the American Geriatrics Society (AGS) developed three transdisciplinary research conferences with a focus on mentoring and leadership skills development. The NIA's GEMSSTAR program evolved from two earlier programs, the AGS' Dennis W. Jahnigen and the Association of Specialty Professors' T. Franklin Williams Career Development Scholars Awards. It supports the continued cultivation of the next generation of medical and surgical specialty researchers with an interest in aging research. The award requires both geriatrics and specialty mentoring and currently provides up to $150,000 a year in direct support to scholars. Additionally, the award requires that scholars have a professional development plan that is complementary to the GEMSSTAR award. The U13 conferences, focused on frailty, models of aging, and cognition, brought together GEMSSTAR scholars, former scholars, innovators, mentors, and leaders in aging research, the specialties, and geriatric medicine. This article describes the themes of each of the GEMSSTAR U13 conferences and highlights the lessons learned on mentoring, team science, aging research networks, and work-life balance. We plan to use these lessons to guide the support we provide to the growing group of emerging leaders who are poised to lead the transdisciplinary research network of the future. J Am Geriatr Soc 67:650-656, 2019.