Susan E. Hardy

Improvement in Usual Gait Speed Predicts Better Survival in Older Adults

OBJECTIVES: To estimate the relationship between 1‐year improvement in measures of health and physical function and 8‐year survival.

Resilience of community-dwelling older persons.

Objectives:  To assess resilience of community‐dwelling older persons using a new scale based on response to a stressful life event and to identify the demographic, clinical, functional, and psychosocial factors associated with high resilience.

The Dynamic Nature of Mobility Disability in Older Persons

To determine the rates of clinically meaningful transitions in mobility disability; evaluate how these transitions differ according to age, sex, and physical frailty; and depict the duration of the resulting episodes of mobility disability.

Underestimation of Disability in Community‐Living Older Persons

OBJECTIVES: When ascertaining the occurrence of disability, long assessment intervals may be problematic because they do not account for the possibility of recovery or for deaths or losses to follow‐up. Our objective was to compare the rates of disability obtained from single follow‐up assessments with those obtained from monthly assessments for intervals up to 24 months.

Executive Function, Memory, and Gait Speed Decline in Well-Functioning Older Adults

BACKGROUND In community-dwelling older adults, global cognitive function predicts longitudinal gait speed decline. Few prospective studies have evaluated whether specific executive cognitive deficits in aging may account for gait slowing over time. METHODS Multiple cognitive tasks were administered at baseline in 909 participants in the Health, Aging, and Body Composition Study Cognitive Vitality Substudy (mean age 75.2 ± 2.8 years, 50.6% women, 48.4% black). Usual gait speed (m/s) over 20 minutes was assessed at baseline and over a 5-year follow-up. RESULTS Poorer performance in each cognitive task was cross-sectionally associated with slower gait independent of demographic and health characteristics. In longitudinal analyses, each 1 SD poorer performance in global function, verbal memory, and executive function was associated with 0.003-0.004 m/s greater gait speed decline per year (p =.03-.05) after adjustment for baseline gait speed, demographic, and health characteristics. CONCLUSIONS In this well-functioning cohort, several cognitive tasks were associated with gait speed cross-sectionally and predicted longitudinal gait speed decline. These data are consistent with a shared pathology underlying cognitive and motor declines but do not suggest that specific executive cognitive deficits account for slowing of usual gait in aging.

Missing Data: A Special Challenge in Aging Research

Scientific evidence should guide clinical care, but special methodological challenges influence interpretation of the medical literature pertaining to older adults. Missing data, ranging from lack of individual items in questionnaires to complete loss to follow‐up, affect the quality of the evidence and are more likely to occur in studies of older adults because older adults have more health and functional problems that interfere with all aspects of data collection than do younger people. The purpose of this article is to promote knowledge about the risks and consequences of missing data in clinical aging research and to provide an organized approach to prevention and management. Although it is almost never possible to achieve complete data capture, efforts to prevent missing data are more effective than analytical “cure.” Strategies to prevent missing data include selecting a primary outcome that is easy to determine and devising valid alternate definitions, adapting data collection to the special needs of the target population, pilot testing data collection plans, and monitoring missing data rates during the study and adapting data collection procedures as needed. Key steps in the analysis of missing data include assessing the extent and types of missing data before analysis, exploring potential mechanisms that contributed to the missing data, and using multiple analytical approaches to assess the effect of missing data on the results. Manuscripts should disclose rates of missing data and losses to follow‐up, compare dropouts with participants who completed the study, describe how missing data were managed in the analysis phase, and discuss the potential effect of missing data on the conclusions of the study.

Fatigue Predicts Mortality in Older Adults

OBJECTIVES: To determine the association between fatigue and survival over 10 years in a population of older community‐dwelling primary care patients.

Methylphenidate for the treatment of depressive symptoms, including fatigue and apathy, in medically ill older adults and terminally ill adults.

BACKGROUND Depressive symptoms, fatigue, and apathy are common symptoms among medically ill older adults and patients with advanced disease, and have been associated with morbidity and mortality. Methylphenidate has been used to treat these symptoms because of its rapid effect. Despite the long history of methylphenidate use for the treatment of depressive symptoms, fatigue, and apathy, there is little definitive evidence to support its use. OBJECTIVE The aim of this paper was to review the efficacy and tolerability of methylphenidate in the treatment of depressive symptoms, fatigue, and apathy in medically ill older adults and adults receiving palliative care. METHODS English-language articles presenting systematic reviews, clinical trials, or case series describing the use of methylphenidate for the treatment of depressive symptoms, fatigue, or apathy in medically ill older adults or adults receiving palliative care were identified. The key words methylphenidate and either depressive, depression, fatigue, or apathy were used to search the Cochrane Database, MEDLINE, PsycINFO, and International Pharmaceutical Abstracts. Included articles addressed depressive symptoms, fatigue, or apathy in (1) older adults (generally, age > or =65 years), particularly those with comorbid medical illness; (2) adults receiving palliative care; and (3) adults with other chronic illnesses. I excluded articles regarding treatment of depression in healthy young adults; bipolar disorder and attention-deficit/hyperactivity disorder; and narcolepsy, chronic fatigue syndrome, and related disorders. RESULTS A total of 19 controlled trials of methylphenidate in medically ill older adults or patients in palliative care were identified. Unfortunately, their conflicting results, small sample sizes, and poor methodologic quality limited the ability to draw inferences regarding the efficacy of methylphenidate, although evidence of tolerability was stronger. The available evidence suggests possible effectiveness of methylphenidate for depressive symptoms, fatigue, and apathy in various medically ill populations. CONCLUSION In the absence of definitive evidence of effectiveness, trials of low-dose methylphenidate in medically ill adults with depression, fatigue, or apathy, with monitoring for response and adverse effects, are appropriate.

Stressful Life Events Among Community-living Older Persons

OBJECTIVES: To identify the life events that older persons experience as most stressful, to evaluate older persons’ perceptions of the consequences of these stressful events for their lives, and to evaluate the relationship of demographic factors and measures of health and functional status to these perceptions.DESIGN: Cross-sectional study.PARTICIPANTS: Seven hundred fifty-four community-living persons aged 70 years or older.MEASURES: During a comprehensive assessment, participants identified the most stressful event that they had experienced in the past 5 years and, subsequently, rated its stressfulness and perceived consequences.RESULTS: Six hundred three participants (80%) identified a stressful life event. Of these, 18% identified a personal illness, 42% the death of a family member or friend, 23% the illness of a family member or friend, and 17% a nonmedical event. Although participants consistently rated their events as highly stressful, they reported widely varied consequences of these events for their lives. While 27% to 59% of participants across the 4 event types reported considerable negative consequences, 17% to 36% reported positive consequences such as starting new activities that have become important to them and changing for the better how they feel about their lives. Dependence in instrumental activities of daily living and depressive symptoms were independently associated with several negative perceived consequences.CONCLUSIONS: Older persons experience a wide array of stressful life events, with only a small minority reporting personal illnesses as the most stressful. Similar stressful events can have either negative or positive consequences for older persons’ lives. This variation in response to stressful events among older persons may indicate different degrees of resilience, a potentially important factor underlying successful aging that deserves further investigation.

Explaining the Effect of Gender on Functional Transitions in Older Persons

Background: Women live longer but experience greater disability than men. The reasons for this gender difference in disability are not well understood. Objective: Our objectives were to determine if the higher prevalence of disability in women is due to greater incidence of disability, longer duration of disability, or both, and to identify factors that potentially explain these gender differences. Methods: 754 community-living persons aged 70 and older who were non-disabled (required no personal assistance) in four essential activities of daily living (ADLs) were assessed monthly for disability for up to 6 years. A multi-state extension of the proportional hazards model was used to determine the effects of gender on transitions between states of no disability, mild disability, severe disability, and death, and to evaluate potential mediators of these effects. Results: Women were more likely to make the transition from no disability to mild disability and less likely to make the transitions from mild to no disability and from both mild and severe disability to death. The gender difference in the transitions between no disability and mild disability was largely explained by differences in gait speed and physical activity, but gender difference in transitions to death persisted despite adjustment for multiple potential mediators. Conclusion: The higher prevalence of disability in women versus men is due to a combination of higher incidence and longer duration, resulting from lower rates of recovery and mortality among disabled women.