Pragmatic and Internal Validity Issues in Sampling in Caregiver Studies

Associations of spousal and non-spousal caregiving with six-year trajectories of depressive symptoms among older women in the Caregiver-Study of Osteoporotic Fractures study

Objectives:Caregiving and becoming widowed are risk factors for depression in older adults, but few studies have examined their combined effect on depressive symptom trajectories. In a cohort of older women (mean age = 80.7 years) from the Caregiver-Study of Osteoporotic Fractures, we used latent class growth curve modeling to identify trajectories of depressive symptoms over approximately six years.Method:We used multinomial logistic regression to assess the relative odds of four depressive symptom trajectories (consistently low, consistently moderate, moderate/increasing, and consistently high), among three groups: spousal caregivers (n = 149), non-spousal caregivers (n = 157), and non-caregivers (n = 422). We also repeated this analysis with combined caregiving status and widowhood as the exposure.Results:Compared to non-caregivers, spousal caregivers had greater relative odds of consistently high versus consistently low depressive symptoms (adjusted odds ratio [aOR] = 3.6, 95% confidence interval [CI]: 1.9, 6.5). Non-spousal caregivers did not differ from non-caregivers in depressive trajectories. Compared to non-caregivers who did not become widowed, both widowed and non-widowed spousal caregivers had greater relative odds of consistently high versus consistently low depressive symptoms (aOR = 4.9, 95% CI: 1.9, 12.7 and aOR = 3.0, 95% CI: 1.5, 6.0, respectively). Non-widowed spousal caregivers, but not widowed spousal caregivers, had a non-statistically-significant trend toward increased relative odds of moderate/increasing depressive symptoms (aOR = 1.5, 95% CI: 0.7, 3.4).Conclusion:Spousal caregiving and widowhood, but not non-spousal caregiving, are associated with trajectories reflecting greater depressive symptoms over time. Informal caregiving is common among older women, and women caring for spouses should be monitored for depression, both during caregiving and after spousal loss.Supplemental data for this article can be accessed online at https://doi.org/10.1080/13607863.2021.1950611.

Caregiving Intensity and Mortality in Older Women, Accounting for Time-Varying and Lagged Caregiver Status: The Caregiver-Study of Osteoporotic Fractures Study

BACKGROUND AND OBJECTIVES

Caregiving is associated with reduced mortality in recent studies. Investigations of caregiving intensity may reveal an underlying mechanism. However, studies of caregiving intensity and mortality have mixed results, perhaps due to imprecise measurement of caregiving intensity, not accounting for healthier persons likely having greater caregiving involvement, or temporal changes in intensity. We examined the relationship between caregiving intensity (based on tasks performed) and mortality, treating intensity and health status as time-varying, and lagging exposure.

RESEARCH DESIGN AND METHODS

Caregiving tasks among 1,069 women in the Caregiver-Study of Osteoporotic Fractures study (35% caregivers) were assessed at 5 interviews conducted between 1999 and 2009. Caregivers were categorized as high intensity if they assisted a person with dressing, transferring, bathing, or toileting; or as low intensity if they assisted with other instrumental or basic activities of daily living (I/ADLs). Alternatively, high intensity was defined as assisting with more than the median number of I/ADL tasks (median-based measure). Mortality was assessed through 2011. Cox proportional hazards models estimated adjusted hazard ratios (aHR) and 95% confidence intervals based on concurrent intensity, and lagging exposure 2 years.

RESULTS

High-intensity caregivers had significantly lower mortality using the median-based measure after lagging exposure (aHR = 0.55, 0.34-0.89). Similar, but not statistically significant associations were observed in non-lagged analyses (aHR = 0.54, 0.29-1.04) and task-specific intensity (aHRs were 0.61 and 0.51). Low-intensity caregivers had similar mortality rates to noncaregivers in all analyses.

DISCUSSION AND IMPLICATIONS

Among older women, high-intensity caregivers had lower mortality rates than noncaregivers. Whether this association extends to other populations merits investigation.

Assessing the Role of Selection Bias in the Protective Relationship Between Caregiving and Mortality

Caregivers have lower mortality rates than noncaregivers in population-based studies, which contradicts the caregiver-stress model and raises speculation about selection bias influencing these findings. We examined possible selection bias due to 1) sampling decisions and 2) selective participation among women (baseline mean age = 79 years) in the Caregiver-Study of Osteoporotic Fractures (Caregiver-SOF) (1999-2009), an ancillary study to the Study of Osteoporotic Fractures (SOF). Caregiver-SOF includes 1,069 SOF participants (35% caregivers) from 4 US geographical areas (Baltimore, Maryland; Minneapolis, Minnesota; the Monongahela Valley, Pennsylvania; and Portland, Oregon). Participants were identified by screening all SOF participants for caregiver status (1997-1999; n = 4,036; 23% caregivers) and rescreening a subset of caregivers and noncaregivers matched on sociodemographic factors 1-2 years later. Adjusted hazard ratios related caregiving to 10-year mortality in all women initially screened, subsamples representing key points in constructing Caregiver-SOF, and Caregiver-SOF. Caregivers had better functioning than noncaregivers at each screening. The association between caregiving and mortality among women invited to participate in Caregiver-SOF (41% died; adjusted hazard ratio (aHR) = 0.73, 95% confidence interval (CI): 0.61, 0.88) was slightly more protective than that in all initially screened women (37% died; aHR = 0.83, 95% CI: 0.73, 0.95), indicating little evidence of selection bias due to sampling decisions, and was similar to that in Caregiver-SOF (39% died; aHR = 0.71, 95% CI: 0.57, 0.89), indicating no participation bias. These results add to a body of evidence that informal caregiving may impart health benefits.

Changes in Caregiving Status and Intensity and Sleep Characteristics Among High and Low Stressed Older Women

STUDY OBJECTIVES

To examine whether change in caregiving status and intensity among community-dwelling older women was associated with sleep characteristics at follow-up, and whether perceived stress modified these associations.

METHODS

The sample included 800 women aged 65 years or older who completed baseline and second follow-up interviews in the Caregiver-Study of Osteoporotic Fractures (Caregiver-SOF). Respondents were categorized into four groups based on change in caregiving status and intensity between the two time points: continuous noncaregivers, ceased caregivers, low-intensity caregivers (continuous caregivers with low/decreased intensity), and high-intensity caregivers (continuous caregivers with high/increased intensity or new caregivers). Perceived Stress Scale scores at the second follow-up were dichotomized into high versus low stress. Sleep outcomes at SOF Visit 8 (which overlapped with Caregiver-SOF second follow-up) included the Pittsburgh Sleep Quality Index total score; and actigraphy-measured total sleep time, sleep efficiency, wake after sleep onset, and sleep latency.

RESULTS

Multivariate-adjusted sleep characteristics did not differ significantly across caregiving groups. Among high-intensity caregivers, however, those with high stress levels had significantly longer wake after sleep onset (mean 82.3 minutes, 95% confidence interval = 70.9-93.7) than those with low stress levels (mean 65.4 minutes, 95% confidence interval = 55.2-75.7). No other sleep outcomes were modified by stress levels. Further, higher stress was significantly associated with worse Pittsburgh Sleep Quality Index scores, regardless of the caregiving group.

CONCLUSIONS

Overall, sleep characteristics did not differ among noncaregivers, ceased caregivers, or those with high-/low-intensity caregiving among older women. However, subgroups of caregivers may be vulnerable to developing sleep problems, particularly those with high stress levels.

Six key topics informal carers of patients with breathlessness in advanced disease want to learn about and why: MRC phase I study to inform an educational intervention

INTRODUCTION

Breathlessness is a common symptom of advanced disease placing a huge burden on patients, health systems and informal carers (families and friends providing daily help and support). It causes distress and isolation. Carers provide complex personal, practical and emotional support yet often feel ill-prepared to care. They lack knowledge and confidence in their caring role. The need to educate carers and families about breathlessness is established, yet we lack robustly developed carer-targeted educational interventions to meet their needs.

METHODS

We conducted a qualitative interview study with twenty five purposively-sampled patient-carer dyads living with breathlessness in advanced disease (half living with advanced cancer and half with advanced chronic obstructive pulmonary disease (COPD). We sought to identify carers' educational needs (including what they wanted to learn about) and explore differences by diagnostic group in order to inform an educational intervention for carers of patients with breathlessness in advanced disease.

RESULTS

There was a strong desire among carers for an educational intervention on breathlessness. Six key topics emerged as salient for them: 1) understanding breathlessness, 2) managing anxiety, panic and breathlessness, 3) managing infections, 4) keeping active, 5) living positively and 6) knowing what to expect in the future. A cross-cutting theme was relationship management: there were tensions within dyads resulting from mismatched expectations related to most topics. Carers felt that knowledge-gains would not only help them to support the patient better, but also help them to manage their own frustrations, anxieties, and quality of life. Different drivers for education need were identified by diagnostic group, possibly related to differences in caring role duration and resulting impacts.

CONCLUSION

Meeting the educational needs of carers requires robustly developed and evaluated interventions. This study provides the evidence-base for the content of an educational intervention for carers of patients with breathlessness in advanced disease.

Survey nonresponse among informal caregivers: effects on the presence and magnitude of associations with caregiver burden and satisfaction

Background

Informal caregiving is becoming more relevant with current trends such as population ageing. However, little is known about nonconsent and nonresponse bias in caregiving research. We investigated nonconsent and nonresponse bias in a sample of informal caregivers who participated in the LifeLines Cohort Study, and were invited for participation in an additional caregiving study.

Methods

We compared socio-demographic characteristics, caregiver health, caregiving situation, and caregiver outcomes of nonconsent and consent caregivers, and nonresponse and response caregivers, on LifeLines data, by using Chi-square tests, Independent Sample T-tests, and Mann-Whitney tests. Furthermore, we examined the influence of nonconsent and nonresponse on the presence and magnitude of the associations between caregiver characteristics and two commonly used caregiving outcomes (caregiver burden and satisfaction). We conducted multinomial logistic regression analyses, including interaction terms with nonconsent and nonresponse.

Results

Within a subcohort of 8443 caregivers, aged >18 years, 5095 caregivers (60 %) gave consent for participation in the caregiving study. Within the subgroup of 2002 caregivers who received the questionnaire, 965 (48 %) responded. Caregivers who were highly involved in caregiving (i.e. high time investment, high caregiver burden), gave more commonly consent to participate, and responded more often to the questionnaire. Nonconsent and nonresponse influenced the associations between caregiver characteristics and caregiver burden for only a few characteristics, mainly indicating the level of caregiving involvement (e.g. time investment, caregiving duration). Especially for caregiver burden, these indicators were stronger for consent and response caregivers than for nonconsent and nonresponse caregivers.

Conclusions

Our findings are important for caregiving research, as they emphasized that participation might not be evenly distributed among caregivers, and that the possibility of nonconsent and nonresponse bias should be considered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-2948-6) contains supplementary material, which is available to authorized users.

The Relationship Between Caregiving and Mortality After Accounting for Time-Varying Caregiver Status and Addressing the Healthy Caregiver Hypothesis

BACKGROUND

Previous studies have shown inconsistent associations between caregiving and mortality. This may be due to analyzing caregiver status at baseline only, and that better health is probably related to taking on caregiving responsibilities and continuing in that role. The latter is termed The Healthy Caregiver Hypothesis, similar to the Healthy Worker Effect in occupational epidemiology. We applied common approaches from occupational epidemiology to evaluate the association between caregiving and mortality, including treating caregiving as time-varying and lagging exposure up to 5 years.

METHODS

Caregiving status among 1,068 women (baseline mean age = 81.0 years; 35% caregivers) participating in the Caregiver-Study of Osteoporotic Fractures study was assessed at five interviews conducted between 1999 and 2009. Mortality was determined through January 2012. Cox proportional hazards models were used to estimate adjusted hazard ratios and 95% confidence intervals adjusted for sociodemographics, perceived stress, and functional limitations.

RESULTS

A total of 483 participants died during follow-up (38.8% and 48.7% of baseline caregivers and noncaregivers, respectively). Using baseline caregiving status, the association with mortality was 0.77, 0.62-0.95. Models of time-varying caregiving status showed a more pronounced reduction in mortality in current caregivers (hazard ratios = 0.54, 0.38-0.75), which diminished with longer lag periods (3-year lag hazard ratio = 0.68, 0.52-0.88, 5-year lag hazard ratios = 0.76, 0.60-0.95).

CONCLUSIONS

Overall, caregivers had lower mortality rates than noncaregivers in all analyses. These associations were sensitive to the lagged period, indicating that the timing of leaving caregiving does influence this relationship and should be considered in future investigations.

The Effect of Transitions in Caregiving Status and Intensity on Perceived Stress Among 992 Female Caregivers and Noncaregivers

BACKGROUND

Informal caregiving, a chronic stressor, is also a dynamic experience, as caregivers may repeatedly enter and exit the role and alter the amount of care they provide. Changes in caregiving status and intensity influence stress, but few studies have evaluated the simultaneous impact of these changes on perceived stress.

METHODS

A total of 1,027 female caregivers and noncaregivers (mean age = 81.7), of which 992 were included in the final sample, were followed for at least two consecutive annual interviews (ie, one interval) and up to five interviews over a 9-year period. Caregiving status was measured by self-report of whether the respondent assisted someone with at least one basic or instrumental activity of daily living; caregiving intensity was dichotomized at the median number of basic or instrumental activity of daily living tasks caregivers performed. The associations between changes in caregiving status and intensity level with Perceived Stress Scale (PSS) score at the end of an interval were estimated using mixed-effects regression models.

RESULTS

Respondents contributed 2,832 intervals. High-intensity caregivers reported the highest stress at the end of an interval, whereas noncaregivers reported the lowest (mean PSS = 18.97 vs 15.73, p < .01). Low-intensity caregivers, whose intensity increased, had higher stress than continuing high-intensity caregivers. Those who stopped caregiving, regardless of intensity level, reported the same amount of stress as noncaregivers.

CONCLUSIONS

Transitions in caregiving status and intensity affect caregiver perceived stress. Continuing high-intensity caregivers and those who transition from low- to high-intensity caregiving report the highest stress of all transition groups, suggesting that stress-reduction interventions should target high-intensity caregivers.

Longitudinal and Reciprocal Relationships Between Depression and Disability in Older Women Caregivers and Noncaregivers

PURPOSE OF THE STUDY

Depressive symptoms and disability each increase the risk of the other, yet few studies have examined reciprocal associations between these conditions in a single study, or over periods longer than 3 years. These associations may differ in older caregivers due to chronic stress, health characteristics, or factors related to caregiving.

DESIGN AND METHODS

Structural equation models were used to investigate relationships between depressive symptoms and disability over 3 interviews spanning 6 years among 956 older women (M = 81.5 years) from the Caregiver Study of Osteoporotic Fractures. Results were evaluated separately for 611 noncaregivers and 345 caregivers to a relative or friend.

RESULTS

In noncaregivers, more depressive symptoms significantly predicted greater disability, whereas greater disability predicted increased depressive symptoms at the next interview in age-adjusted models. In contrast, there was not a significant relationship between depression and disability in either direction for caregivers. Further adjustment for body mass index and medical condition variables did not change these relationships.

IMPLICATIONS

Caregivers did not exhibit longitudinal or reciprocal relationships between depressive symptoms and disability observed in noncaregivers. It is possible that older women caregivers are buffered by better physical condition or social interactions related to caregiving activities.

Depressive symptoms among dementia caregivers: role of mediating factors

OBJECTIVE

To compare depressive symptoms between caregivers to persons with dementia and other illnesses and determine whether caregiver role captivity and care recipient disruptive behaviors mediate this association.

METHODS

Prospective cohort study of older women in four U.S. communities followed from 1999 to 2009. Home-based interviews were used in 345 caregiving participants from the Caregiver-Study of Osteoporotic Fractures. Caregiver status was based on self-report of performing one or more instrumental or basic activities of daily living for a care recipient. Depressive symptoms were measured using the 20-item Center for Epidemiologic Studies Depression Scale. Scores of 16 or greater represented high depressive symptoms. Caregiver role captivity and care recipient problematic behaviors were measured using validated instruments.

RESULTS

Approximately one third of the caregivers cared for a person with dementia. High depressive symptoms were more common among dementia caregivers (22.8% versus 11.2%, p <0.001) (unadjusted odds ratio: 2.12; 95% confidence interval [CI]: 1.20-3.74). This association was completely mediated by caregiver role captivity and care recipient problematic behaviors. In adjusted results, high depressive symptoms were associated with middle and highest tertiles of role captivity (adjusted odds ratios [AOR]: 5.01; 95% CI: 2.31-11.05 and AOR: 9.41; 95% CI: 3.95-22.40 for the middle and highest tertiles, respectively) and care recipient problematic behaviors (AOR: 2.52; 95% CI: 1.02-6.19 and AOR: 5.26; 95% CI: 2.00-13.8 for the middle and highest tertiles, respectively).

CONCLUSION

Older caregivers to persons with dementia are at increased risk of high depressive symptoms. Targeting problematic behaviors among dementia patients and addressing aspects of dementia care that result in role captivity may ameliorate caregiver depression.

Caregiving and cognitive function in older women: evidence for the healthy caregiver hypothesis

OBJECTIVES

Recent findings of better health outcomes in older caregivers than noncaregivers suggest a healthy caregiver hypothesis (HCH) model may be more appropriate than the stress process model for evaluating the health effects of caregiving. In a cross-sectional study, we tested the HCH on two cognitive domains: verbal memory and processing speed.

METHOD

Participants from the Caregiver Study of Osteoporotic Fractures who had a 2-year follow-up interview were categorized as continuous caregivers (n = 194), former caregivers (n = 148), or continuous noncaregivers (n = 574). The Hopkins Verbal Learning Test (HVLT; memory) and Digit Symbol Substitution Task (DSST; processing speed) were administered at the follow-up interview.

RESULTS

Continuous caregivers had better memory performance and processing speed than continuous noncaregivers: adjusted mean scores for HVLT were 18.38 versus 15.80 (p < .0001), and for DSST were 35.91 versus 34.38 (p = .09).

DISCUSSION

Results support the HCH model for cognitive outcomes in older women caregivers; however, the relationship may be domain specific.

Association between insomnia symptoms and weight change in older women: caregiver--study of osteoporotic fractures study

OBJECTIVES

To determine whether self-reported insomnia symptoms were associated with weight change in older women and whether caregiving, comorbidities, sleep medication, or stress modified this association.

DESIGN

One-year prospective study conducted in four communities from 1999 to 2003 nested within a larger cohort study.

SETTING

Home-based interviews.

PARTICIPANTS

Nine hundred eighty-eight participants (354 caregivers and 634 noncaregivers) from the Caregiver--Study of Osteoporotic Fractures.

MEASUREMENTS

Self-reported insomnia symptoms in the previous month: trouble falling asleep, trouble staying asleep, and waking early and having trouble getting back to sleep. Weight was measured at baseline and 12 months.

RESULTS

The average weight change was -1.9 ± 7.8 pounds. Trouble staying asleep was significantly associated with an average weight loss of 1.3 pounds (P = .03) in multivariable analyses. Neither of the other insomnia symptoms was associated with weight change. Use of sleep medications modified the association between trouble falling asleep (interaction term P = .03) and weight change. Insomnia symptoms were associated with weight loss only in women not taking sleep medications. Neither caregiving status, presence of multiple comorbidities, nor stress modified the association.

CONCLUSION

Trouble staying asleep was associated with weight loss over 12 months in older women. Practitioners should inquire about sleep habits of patients presenting with weight loss, because this may identify a marker of declining health and may be a factor that can be modified.

Mortality associated with caregiving, general stress, and caregiving-related stress in elderly women: results of caregiver-study of osteoporotic fractures

OBJECTIVES

To investigate the separate and combined effects of caregiver status and high stress on mortality risk over 8 years in elderly women.

DESIGN

Prospective cohort study conducted in four U.S. communities followed from 1999/01 (baseline) to December 31, 2007.

SETTING

Home-based interviews.

PARTICIPANTS

Three hundred seventy-five caregiver and 694 noncaregiver participants from the Caregiver-Study of Osteoporotic Fractures (Caregiver-SOF) who participated in the baseline Caregiver-SOF interview.

MEASUREMENTS

Caregiver status was based on SOF respondents' self-report of performing one or more instrumental or basic activities of daily living for a relative or friend with impairments. Two measures of stress were used: Perceived Stress Scale and stress related to caregiving tasks. All-cause mortality was the outcome.

RESULTS

Caregivers were more stressed than noncaregivers; 19.7% of caregivers and 27.4% of noncaregivers died. Mortality was lower in caregivers than noncaregivers (adjusted hazard ratio, (AHR)=0.74, 95% confidence interval (CI)=0.56-0.89). High-stress respondents had greater mortality risk than low-stress respondents over the first 3 years of follow-up (AHR=1.81, 95% CI=1.16-2.82) but not in later years. Likewise, high-stress caregivers and noncaregivers had higher mortality risk than low-stress noncaregivers, although low-stress caregivers had significantly lower mortality than did noncaregivers, whether perceived stress or caregiving-related stress was measured (AHR=0.67 and 0.57). Similar results were observed in analyses comparing spouse caregivers with married noncaregivers.

CONCLUSION

Short-term effects of stress, not caregiving per se, may increase the risk of health decline in older caregivers.

Caregiving, metabolic syndrome indicators, and 1-year decline in walking speed: results of Caregiver-SOF

Background.

Chronic stress may lead to health decline through metabolic syndrome. Thus, persons in stressful caregiving situations who also have more indicators of metabolic syndrome may experience more decline than other caregivers or noncaregivers.

Methods.

The sample included 921 women (338 caregivers and 583 noncaregivers) from the Caregiver-Study of Osteoporotic Fractures study. Participants had home-based baseline and 1-year follow-up interviews between 1999 and 2003. At baseline, caregivers were categorized as long term (³4 years) versus short term (<4 years), and caring for someone with Alzheimer's disease/dementia or not. A metabolic risk composite score was the sum of four indicators: body mass index ³30, and diagnosis or using medications for hypertension, diabetes, or high cholesterol. Walking speed (m/second) was measured at both interviews.

Results.

Walking speed declined for the total sample (adjusted mean = −0.005 m/second, ±0.16) over an average of 1.04 years (±0.16). Overall, caregiving was not associated with decline. Increasing metabolic risk score was associated with greater decline for the total sample and long-term and dementia caregivers, but not other caregivers or noncaregivers. Metabolic risk score modified the adjusted associations between years of caregiving and dementia caregiving with walking speed decline (p values for interaction terms were 0.039 and 0.057, respectively). The biggest declines were in long-term caregivers and dementia caregivers who also had 3–4 metabolic indicators (−0.10 m/second and −0.155 m/second, respectively).

Conclusions.

Walking speed declined the most among older women who had both stressful caregiving situations and more metabolic syndrome indicators, suggesting these caregiver subgroups may have increased risk of health decline.

Caregiving intensity and change in physical functioning over a 2-year period: results of the caregiver-study of osteoporotic fractures

It is unknown whether caregivers who perform more caregiving tasks have a greater decline in health from higher stress or less decline because of better health, staying active, or psychological factors. This 1999-2004 US study examined caregiving intensity and 2-year change in performance-based functioning among 901 elderly women from the Caregiver-Study of Osteoporotic Fractures sample. Caregivers were categorized as high (n = 167) or low (n = 166) intensity based on how many activities of daily living they performed for the care recipient. Caregiving intensity status and physical performance score (sum of quartiles of walking pace, grip strength, and chair-stand speed; range, 0-9) were assessed at baseline and at 2 annual follow-up interviews. At baseline, high-intensity caregivers reported the most stress but had the best physical functioning; noncaregivers (n = 568) had the poorest physical functioning (adjusted scores = 5.09 vs. 4.54, P = 0.03). Low-intensity caregivers declined more than noncaregivers over 2 years, but high-intensity caregivers did not (adjusted difference = -0.33, P = 0.07 vs. 0.03, P = 0.89). Among respondents with the same caregiving status at baseline and 1-year interviews, high-intensity caregivers maintained the highest physical performance throughout follow-up. Higher levels of physical performance persisted over 2 years among high-intensity caregivers, which did not support the traditional stress hypothesis.

Positive affect and incidence of frailty in elderly women caregivers and noncaregivers: results of Caregiver-Study of Osteoporotic Fractures

OBJECTIVES

To determine whether positive affect is associated with a lower incidence of frailty over 2 years in elderly community-dwelling women and to test the stress-buffering hypothesis by evaluating whether these associations differed in caregivers and noncaregivers.

DESIGN

Prospective cohort study with three annual interviews conducted in four U.S. communities between 1999 and 2004.

SETTING

Home-based interviews.

PARTICIPANTS

Three hundred thirty-seven caregiver and 617 noncaregiver participants from the Caregiver-Study of Osteoporotic Fractures (Caregiver-SOF) who were not frail at the baseline Caregiver-SOF interview.

MEASUREMENTS

High and low positive affect and depressive symptoms were derived from the baseline 20-item Center for Epidemiologic Studies Depression Scale. Frailty was the development of three or more indicators (weight loss, exhaustion, slow walking speed, or weak grip strength) at the first or second follow-up interview.

RESULTS

Respondents' mean age was 81.2. Caregivers and noncaregivers had similar levels of positive affect (56.3% vs 58.3%) and frailty incidence (15.4% vs 15.9%) but differed in perceived stress (mean Perceived Stress Scale score 16.7 vs 14.8, P<.001). Frailty risk was lower in respondents with high positive affect than in those with low positive affect in the total sample (adjusted hazard ratio (HR)=0.49, 95% confidence interval (CI)=0.35-0.70), caregivers (adjusted HR=0.44, 95% CI=0.24-0.80) and noncaregivers (adjusted HR=0.50, 95% CI=0.32-0.77).

CONCLUSION

These findings add to the evidence that positive affect protects against health decline in older adults, although it had no additional stress-buffering effect on health in elderly caregivers.

Caregiving, mortality, and mobility decline: the Health, Aging, and Body Composition (Health ABC) Study

BACKGROUND

Although caregivers report more stress than noncaregivers, few studies have found greater health decline in older caregivers. We hypothesized that caregivers may be more physically active than noncaregivers, which may protect them from health decline.

METHODS

The sample included 3075 healthy adults from the Health, Aging, and Body Composition (Health ABC) Study. They were aged 70 to 79 years in April 1997 to June 1998 and resided in Memphis, Tennessee, or Pittsburgh, Pennsylvania. Caregivers (680 [22.1%]) were participants who provided regular care or assistance for a child or a disabled or sick adult. Outcomes included all-cause mortality and incident mobility limitation (defined as difficulty walking one-quarter mile or climbing 10 steps on 2 consecutive semiannual contacts) during 8 years. Total physical activity included daily routine, exercise, and caregiving activity.

RESULTS

Overall, 20.6% of caregivers died and 50.9% developed mobility limitations vs 22.0% and 48.9% of noncaregivers, respectively. Associations differed by race and sex. Mortality and mobility limitation rates were 1.5 times higher in white caregivers (eg, among white female caregivers, adjusted hazard ratio for mortality, 1.6; 95% confidence interval, 1.0-2.5) but not for black female caregivers vs noncaregivers (adjusted hazard ratio for mortality, 0.9; 95% confidence interval, 0.5-1.4). Physical activity mediated these associations in most race-sex groups. High-intensity caregivers (ie, caregiving > or =24 hours per week) had elevated rates of decline when adjusted for physical activity but lower rates when not adjusted for activity.

CONCLUSION

Older white caregivers have poorer health outcomes than black female caregivers. Physical activity appears to mask the adverse effects of high-intensity caregiving in most race-sex groups.

Mental health and physical health of family caregivers for persons with dementia: a comparison of African American and white caregivers

This investigation analyzed the differences between African American and white caregivers in the effects of family caregiving for a person with dementia on mental health and physical health variables (including subjective health, reported diseases and cardiovascular measures). A population-based sample of 102 caregivers is compared with 102 non-caregivers matched on ethnicity, gender and age. There were no significant group differences for mental health effects. Most significant physical health effects were attributable to main effects of ethnicity rather than caregiving status. However, African American caregivers had higher diastolic blood pressure than all other groups, a finding consistent with group-specific risk for circulatory system disorders.

Korean version of the Revised Caregiving Appraisal Scale: a translation and validation study

AIM

This paper is a report of a study to examine the reliability and validity of a Korean version of the Revised Caregiving Appraisal Scale with Korean caregivers of older stroke survivors.

BACKGROUND

The Revised Caregiving Appraisal Scale was developed in the United States of America for an American English-speaking population to measure primary caregivers' appraisals of potential stressors and the efficacy of their coping efforts related to caregiving experiences.

METHODS

Using the back-translation method, the instrument was translated into Korean. The Korean version of the Revised Caregiving Appraisal Scale was self-administered by 147 primary family caregivers recruited from three outpatient clinics and two home health agencies in Korea. The study was conducted in 2005.

RESULTS

In this sample, Cronbach's alpha for the total scale was 0.86. Reliability coefficients for each of the five subscales ranged from 0.40 to 0.85. Two subscales, burden and satisfaction, showed good reliability; one subscale, impact, showed marginally acceptable reliability; two subscales, mastery and demand, had low reliability. Principal components factor analysis of the Korean version of the Revised Caregiving Appraisal Scale yielded six factors. Except for the mastery domain, which was divided into two factors, the other factors were similar to those in the original scale.

CONCLUSION

The Korean version of the Revised Caregiving Appraisal Scale had adequate reliability and validity in a sample of Korean caregivers of stroke survivors. It can be used to assess the impact of caregiving and interventions on Korean caregiver attitudes. Further studies are needed with different categories of caregiver.

Leisure-time exercise and overall physical activity in older women caregivers and non-caregivers from the Caregiver-SOF Study

BACKGROUND

Elderly caregivers report less leisure-time physical activity than same-aged non-caregivers. However, through caregiving tasks, caregivers may be as physically active as non-caregivers. This study compared leisure-time exercise and overall physical activity in elderly women caregivers and non-caregivers.

METHODS

The sample included 179 caregivers (153 cared for spouses and 26 for other relatives or friends) and 670 non-caregivers who were participants in the Study of Osteoporotic Fractures. Leisure-time exercise was based on respondents' report of walking for exercise or other regular exercise at least once a week. High overall physical activity included leisure-time exercise or being in the top quartile of walking and climbing stairs during one's daily routine.

RESULTS

Leisure-time exercise was lower in spouse caregivers (adjusted odds ratio (OR) and 95% confidence interval (CI) = 0.64, 0.41-1.00) and non-spouse caregivers (OR = 0.39, 95% CI = 0.16-0.95) than married non-caregivers. Differences in overall physical activity between caregivers and married non-caregivers were smaller and not statistically significant. Caregivers who climbed stairs at least 15 min/day during caregiving tasks reported more overall physical activity than non-caregivers (OR = 4.06, 95% CI = 1.23-13.36).

CONCLUSIONS

Studies comparing physical activity in caregivers and non-caregivers should assess activities performed during routine caregiving tasks.