Informal Caregiving for Older Americans: An Analysis of the 2011 National Study of Caregiving. Analysis Measures


Measures used in this report include both care-recipient characteristics drawn from the NHATS and caregiver characteristics and experience drawn from the NSOC.

Care-Recipient Measures

The care-recipient measures used are a hierarchical assistance level measure developed and further described in Freedman & Spillman (2013), a dementia measure developed and described in Kasper et al. (2013b, 2014), and an indicator that the NHATS respondent is living in a supportive care setting other than a nursing home.

As noted, only NHATS respondents reporting assistance in the last month with self-care or mobility activities, help with household activities for reasons related to health or functioning, or living in supportive care settings are eligible to have informal caregivers selected for the NSOC. Self-care activities include bathing, dressing, eating, and toileting. Mobility-related activities include getting out of bed, getting around inside one’s home or building, and leaving one’s home or building. Taken together, self-care and mobility activities correspond to ADLs. Household activities include laundry, hot meals, shopping for personal items, paying bills/banking, handling medications, corresponding to IADLs. These activities were grouped into a three-category hierarchical measure identifying NHATS respondents as receiving assistance only with household activities, receiving assistance with 1-2 self-care or mobility activities, or receiving assistance with 3+ self-care or mobility activities.

The dementia measure used also is a three-category measure classifying NHATS respondents as having probable dementia, possible dementia, or no dementia based on: (1) a report that a doctor told the sample person he/she had dementia or Alzheimer’s disease; (2) a score indicating probable dementia on a screening instrument (the AD8; Galvin 2005, 2006) administered to all proxy respondents; and (3) results from cognitive tests that evaluate memory, orientation and executive function (Kasper et al. 2013).

Informal Caregiver Measures

NSOC gathered detailed information about each informal caregiver’s caregiving experience, caregiving support, and demographic, socioeconomic, and family characteristics. In this report, we focus primarily on the type and amount of help provided in the last month, work and family situation, positive and negative aspects of caregiving (i.e., gains from and burdens of caregiving activities), physical and mental health (including symptoms and impairments that limited their activities), participation in valued activities and whether caregiving limited participation, and subjective well-being.

Type and Amount of Help. Each NSOC respondent reported the total hours of care they provided in the month prior to interview and the proportion devoted to self-care or mobility assistance. In this report, we focus only on the total hours of care each caregiver-reported. NSOC respondents reported whether they helped with activities in five domains of care:

  • self-care and mobility activities;
  • household activities;
  • ransportation;
  • health or medical care activities; and
  • interactions relating to the health care system and providers.

In addition to examining whether each caregiver assisted with individual tasks, we constructed indicators of whether each caregiver assisted with any task in each domain, measures of engagement and specialization, and a hierarchical measure of the intensity of caregiving.

We used two measures to characterize the engagement of each caregiver in the recipient’s care. The first measure of engagement and the most common in the literature is whether the caregiver assisted with activities in the first domain, self-care or mobility activities, which are associated both with greater personal contact and with greater dependency. This measure is used throughout the report. The second measure differentiates caregivers who help with tasks in all domains in which the recipient receives help from those who specialize in a subset of activities. To construct this measure, we compared the specific tasks with which each caregiver helped and the full array of tasks with which the recipient received help from any network member. Using this information, we constructed an indicator of whether each caregiver provided assistance across all domains in which the care-recipient received help (not specializing), or only a subset of domains (specializing).

Finally, we used the monthly hours of care provided as a measure of caregiving intensity, to examine the relationship between caregiving intensity and subjective well-being and burden.

Work and Family. We examine each caregiver’s age, relationship to the care-recipient, gender, and whether they worked for pay. For employed caregivers, we also examine hours worked in the last week. For those who were employed but did not work in the last week, hours were assessed for the most recent week when they did work. For caregivers other than spouses, we also examined whether the caregiver lived with the care-recipient, marital status, whether the caregiver had children under age 18, and employment and hours worked.

Positive and Negative Aspects of Caregiving. The primary measures used to characterize positive and negative aspects of caregiving draw on four items assessing perceived gains from caregiving and four items assessing perceived negative aspects of caregiving (Pearlin et al. 1990, Lawton et al. 1989). Each item has three response categories: very much, somewhat, or not so much. Both sets of questions were preceded by a neutral introduction in which the interviewer asked the respondent to listen to the statements and “answer whether this describes your situation…”. Values were rescaled so that each item was valued from 0 (not so much) to 2 (very much). Factor analysis indicated that the two sets of items represented two factors, one positive with loadings of 0.52 or higher (alpha=0.70) and the other negative with loadings of 0.58 or higher (alpha=0.75). Each set of items was then combined to create positive and negative scales valued 0-8. We also examined three items in which respondents were asked where they experienced financial, emotional, and physical “difficulty,” and if so, to rate the level of difficulty of each type on a scale of 1-5. Only 94 (<5%) of the 1996 respondents in the analysis sample was missing any of the 11 items. Missing values were imputed separately for positive, negative, and difficulty items using a vector approach that matched donors and recipients by residential setting, the reported values for the vector of positive (negative, or difficulty) items, relationship to care-recipient, gender, and age. Donors were respondents with the respective vectors fully reported.

Physical and Mental Health. To characterize the health of informal caregivers, we drew on self-reported health; two scales measuring depression and anxiety, respectively; sleep problems; and severity of symptoms or impairments. Depression and anxiety scales were created by combining two questions about the frequency of current symptoms of depression and two about generalized anxiety and rescaling the result from 2-8 to 0-6. For each scale, a cut point of 3 was used (Kroenke et al. 2009; Lowe et al. 2009). Sleep problems were assessed as the frequency of difficulty of falling back to sleep. Severity of symptoms or impairments were assessed as the frequency with which pain, upper or lower body weakness, low energy or exhaustion, or breathing problems limited activities.

Participation and Well-Being. We also constructed measures of restricted participation in valued activities because of caregiving and subjective well-being. We measured participation restriction using four items about visiting in person with friends or family; attending religious services; participating in clubs, classes, or other organized activities; and going out for enjoyment in the month prior to interview. We constructed a count of the number of activity restrictions, based on the caregiver’s rating the activity as somewhat or very important and reporting that caregiving ever prevented participation in the activity in the last month. For subjective well-being, we created a score for each caregiver from four items reflecting positive and negative emotions (frequency from every day to never in the last month of feeling cheerful, bored, full of life, upset) and three reflecting self-realization (extent of disagreement with statements about purpose in life, self-acceptance, and environmental mastery). Factor analysis confirmed that these items formed one factor with loadings 0.74 or higher (alpha=0.92). Only 62 respondents (3% of the analysis sample) were missing any of the seven items. Values were imputed using the vector approach described above.

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