Aging is often conceptualized as a developmental challenge to maintain balance between the gains and losses of resources necessary for adaptation to age-related change, with losses increasing over the lifespan [
Studies on multiple resources and successful aging among older adults have grown tremendously [
In addition, because clinical work and empirical research may be tiring and confusing for older participants, a reduced version of the five OARS resources as modeled by five latent variables would prove helpful in reducing the time required to assess older adults’ resources. However, few studies have specified the OARS resources as latent variables [
The purpose of this study was to specify and test the latent factor structure of the five OARS resources administered to participants in their 60s, 80s, and 100s. We hypothesized that (a) the resource model proposed by Fillenbaum [
Participants were selected through the assistance of the University of Georgia Survey Research Center, the Office of the Governor of Georgia, the media, and local older adult service organizations [
The data collection at phase one included 321 older adults (217 women, 104 men), classified as sexagenarians (
Sample demographic characteristics.
Variables | Time 1 | Time 2 |
| ||
---|---|---|---|---|---|
|
% |
|
% | ||
Sex | 1.59 | ||||
Male | 104 | 32.4 | 60 | 29.9 | |
Female | 217 | 67.6 | 141 | 70.1 | |
| |||||
Race | 2.61 | ||||
Black | 89 | 27.7 | 62 | 30.8 | |
White | 232 | 72.3 | 139 | 69.2 | |
| |||||
Age group | 18.86*** | ||||
60s | 91 | 28.3 | 70 | 34.8 | |
80s | 93 | 29.0 | 63 | 31.3 | |
100s | 137 | 42.7 | 68 | 33.8 | |
| |||||
Education | 6.19 | ||||
0-8 years | 90 | 28.2 | 55 | 28.8 | |
High school | 84 | 26.3 | 42 | 22.0 | |
Business/trade school | 23 | 7.2 | 14 | 7.3 | |
College | 75 | 23.6 | 44 | 23.0 | |
Graduate school | 47 | 14.7 | 36 | 18.8 | |
| |||||
Self-rated health | 4.7 | ||||
Excellent | 67 | 21.1 | 39 | 20.2 | |
Good | 159 | 50.2 | 93 | 48.2 | |
Fair | 79 | 24.9 | 52 | 26.9 | |
Poor | 12 | 3.8 | 9 | 4.7 |
Because of rounding, percentages may not add to 100.
***
Differences between participants at Time 1 and participants at Time 1 and Time 2.
Variables | Time 1 Only | Time 1 and Time 2 |
|
||
---|---|---|---|---|---|
|
SD |
|
SD | ||
Mini-Mental (MMSE) | 25.30 | 2.72 | 26.31 | 3.01 | −3.03** |
Short Portable (SPMSQ) | 8.63 | 1.58 | 9.04 | 1.38 | −2.41* |
Economic Resources | 4.73 | 1.48 | 4.82 | 1.47 | .48 |
Mental Health | 5.12 | 1.33 | 5.27 | 1.24 | .97 |
IADLs | 4.81 | 1.30 | 5.25 | 1.19 | 3.02** |
Physical Health | 3.73 | 1.70 | 4.24 | 1.58 | 2.73** |
Social Resources | 4.49 | 1.55 | 4.57 | 1.47 | .42 |
*
Because the purpose of this study was to develop a latent variable model for the five OARS resources, in this section we provide a brief overview of the measures based upon Fillenbaum’s [
Six questions were asked; examples included “How well does the amount of money you have take care of your needs—very well, fairly well, or poorly?” and “Please tell me how well you think you are now doing financially as compared to other people your age—better, about the same, or worse?” These items were scaled from 0: poorly or worse to 2: very well or better.
Satisfaction (six items), sleep disturbance (two items), lethargy (6 items), and paranoid (three items) comprised the four dimensions of Mental Health [
Two commonly used dimensions, instrumental activities of daily living (IADL; seven items) and physical activities of daily living (PADLs; six items), comprised the self-care capacity assessment. An example of an IADL question included “Can you do your housework?” scaled so that 2: without help (can clean floors, etc.); 1: with some help (can prepare some things but unable to cook full meals yourself) or 0: are you completely unable to prepare any meals? A PADL question was “Can you dress and undress yourself” scaled so that 2: without help (able to pick out clothes, dress and undress yourself) 1: with some help, or 0: are you completely unable to dress and undress yourself?
Three questions assessing subjective self-rated health were included. For example, participants responded to “How would you rate your overall health at the present time—excellent, good, fair, or poor?” scaled so that 0: poor and 3: excellent.
Social Resources were measured using seven questions. An example of a question focusing on the interaction aspect of social support was “How many people do you know well enough to visit with in their homes?” Participants chose from a scale of 0: none to 3: five or more. An assessment of dependability of social support included two questions. These questions were answered 1: yes and 0: no. For example, one question was “Do you have someone you can trust and confide in?” A third assessment of the affective domain of social support also included two questions, scaled 1: yes and 0: no. For example, one question was “Do you see your relatives and friends as often as you want to or not?”
The analyses conducted to confirm a measurement model included the following steps for each resource: (a) specifying and testing Fillenbaum’s subscales; (b) adapting Fillenbaum’s recommendations when modeling difficulties were encountered; (c) employing exploratory factor analyses (i.e., principal axis factoring retaining three factors with oblique rotation) to assess relationships within the data and to posit possible indicators for latent constructs; (d) testing the measurement model by confirmatory factor analyses. We developed at least three indicators for each resource and then tested the latent variable measurement model via confirmatory factor analysis. Table
OARS resources latent variable measurement model results.
Construct/indicators | Loadings ( |
Uniqueness ( |
Loadings ( |
Uniqueness ( |
---|---|---|---|---|
T1* | T2** | |||
|
||||
Sufficient Income | .81b | .66 | .96b | .93 |
Overall Income | .70 | .49 | .61 | .37 |
Meet Payments | .63 | .40 | .30 | .09 |
|
||||
Exciting | .60b | .36 | .53b | .28 |
Overall Mental Health | .53 | .29 | .49 | .24 |
Life Satisfaction | .50 | .25 | .69 | .47 |
IADLS | ||||
Getting Out | .89b | .80 | .94b | .88 |
Housework | .88 | .78 | .94 | .88 |
Medicine | .65 | .42 | .77 | .59 |
|
||||
Low Troubles | .70b | .49 | .86b | .73 |
Overall Physical Health | .66 | .44 | .49 | .24 |
Comparative Health | .46 | .21 | .48 | .23 |
|
||||
Phone Talk | .64b | .41 | .94b | .89 |
Visit Network Number | .47 | .22 | .08 | .01 |
Visits With Others | .42 | .17 | .29 | .08 |
aParameter estimates are from the standardized solution. bThese indicator loadings were fixed to 1.0 (unstandardized) for model identification; all estimated loadings
*T1 Fit Indices: MLR
**T2 Fit Indices: MLR
We used full-information maximum likelihood (FIML) to estimate our models [
Exploratory factor analyses were conducted using SPSS 18.0, whereas confirmatory factor analyses and structural equation modeling were conducted with
Inspection of the
Based on the previous exploratory factor analyses, we specified and tested a measurement model using confirmatory factor analysis and comprised of the five factors and their respective indicators as previously discussed. However, in the first test of the measurement model, loneliness did not significantly load on the latent variable for Social Resources at Time 1 (
The five latent variables were significantly correlated with one another at each measurement occasion with a few exceptions at Time 2 (Table
Correlation Matrix of OARS Resources Latent Variables (Time1 below the diagonal; Time 2 above the diagonal).
1 | 2 | 3 | 4 | 5 | |
---|---|---|---|---|---|
1. Economic Resources | — | .26** | .43** | .27** | .08 |
2. Physical Health | .46** | — | .15 | .58** | .14 |
3. Mental Health | .60** | .83** | — | .38** | .25 |
4. IADLS | .21** | .56** | .42** | — | .45** |
5. Social Resources | .27** | .34** | .35** | .50** | — |
**
Correlation matrix of indicators for OARS measurement model (Time 1 below the diagonal; Time 2 above the diagonal).
Variables | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
(1) Age Group | — | −.18** | .02 | −.08 | −.22** | −.23** | −.13 | −.72** | −.71** | −.47** | −.27** | −.10 | −.09 | −.40** | −.18** | −.03 |
(2) Sufficient Income | −.05 | — | .58** | .28** | .17** | .18** | .32** | .27** | .25** | .12 | .19** | .30** | .04 | .14 | −.02 | .16 |
(3) Overall Income | .07 | .56** | — | .22** | .07 | .14 | .21* | .02 | .04 | −.01 | .02 | .16* | .04 | .08 | .10 | .09 |
(4) Meet Payments | −.04 | .55** | .41** | — | .09 | .06 | .14 | .12 | .10 | .06 | .21** | .10 | .13 | −.02 | −.06 | −.01 |
(5) Exciting | −.24** | .22** | .27** | .20** | — | .29** | .35** | .23** | .17 | .22** | .05 | .13 | −.09 | .14* | .06 | .20** |
(6) Overall Mental Health | −.08 | .28** | .31** | .16** | .27** | — | .33** | .16** | .21** | .07 | .00 | .33** | .01 | .07 | .13* | .03 |
(7) Life Satisfaction | −.10 | .22** | .24** | .24** | .38** | .23** | — | .19* | .26** | .20* | .09 | .18** | −.02 | .16** | .04 | .17** |
(8) Getting Out | −.69** | .17** | .11 | .18** | .33** | .13** | .20** | — | .88** | .73** | .46** | .32** | .17* | .40** | .13 | .02 |
(9) House Work | −.63** | .04 | .07 | .16** | .29** | .11 | .14** | .79** | — | .72** | .48** | .27** | .16* | .40** | .07 | .07 |
(10) Medicine | −.38** | .19** | .00 | .02 | .21** | .03 | .07 | .55** | .61** | — | .38** | .27** | .14 | .31** | .07 | .05 |
(11) Low Troubles | −.26** | .19** | .25** | .21** | .32** | .26** | .28** | .41** | .35** | .30** | — | .40** | .41** | .09 | −.14* | .00 |
(12) Overall Physical Health | −.16** | .30** | .29** | .22** | .33** | .48** | .20** | .28** | .24** | .17** | .45** | — | .33** | .16* | .03 | .08 |
(13) Comparative Health | −.28** | .08 | .12 | .11 | .25** | .17** | .13** | .29** | .27** | .19** | .35** | .28** | — | .10 | −.13 | −.03 |
(14) Phone Talk | .23** | .04 | .18** | .03 | .16** | .08 | .11 | .35** | .30** | .20** | .15* | .20** | .01 | — | .07 | .27** |
(15) Visit Network Number | −.21** | .03 | .07 | .09 | .11** | .05 | .04 | .32** | .21** | .19 | .10 | .13 | .09 | .24** | — | .19 |
(16) Visits With Others | −.03 | .14** | .05 | −.01 | .10 | .09 | .11 | .10 | .00 | .08 | .11 | .09 | −.01 | .31** | .25** | — |
Means | Time 1 |
|
1.14 | 1.52 | 1.44 | 1.78 | 1.41 | 2.06 | 1.75 | 1.63 | 1.58 | 1.83 | 1.29 | 1.89 | .86 | 2.41 |
Time 2 |
|
.99 | 1.52 | 1.42 | 1.72 | 1.42 | 1.97 | 1.77 | 1.55 | 1.47 | 1.77 | 1.17 | 1.83 | .78 | 2.41 | |
SD | Time 1 |
|
.78 | .78 | .52 | .50 | .57 | .70 | .47 | .46 | .59 | .40 | .76 | .77 | .62 | .85 |
Time 2 |
|
.83 | .78 | .77 | .58 | .57 | .72 | .49 | .55 | .67 | .51 | .78 | .80 | .61 | .89 |
Finally, we attempted a nested model test for factorial invariance over time by constraining the loadings of each indicator at Time 1 equal to the same indicator at Time 2. Also, the residual for each indicator at Time 1 was correlated with its counterpart at Time 2. This constrained or nested model did not fit the data well: MLR
As a follow-up, we decided to fit a measurement model without the Social Resources latent variable. The unconstrained or base model, including the four latent variable resource constructs (without Social Resources at Time 1 and Time 2), specified with correlated residuals across time, fit the data well: MLR
The focus of this study was a widely used integral part of the
Five latent variables with three indicators each, corresponding to the five OARS resources, were specified; the combined measurement model fit the data adequately using a sample of older adults in their 60s, 80s, and 100s. Three results from the measurement analyses are noteworthy. First, because of advances in SEM programs and techniques allowing specification of measurement error and latent factor modeling, a comprehensive measurement model of the five OARS resources would prove useful to researchers and those assessing and caring for older adults. With the exception of Social Resources at Time 2, researchers employing the OARS may confidently specify the measurement model tested in this study. The measurement model tested in this study fit the data well at Time 1 and Time 2. Factor loadings (except those of Social Resources at Time 2) were significant and substantive, providing adequate evidence of an acceptable latent variable measurement model for the five OARS resources.
Second, supplementary analyses of factorial invariance over time, conducted without Social Resources at Time 2, revealed that in this sample, the four latent variables (i.e., Economic Resources, IADL, Physical Health, and Mental Health) fit the data well and did not change significantly over time. It is noted that for the younger participants (i.e., those in their 60s and 80s), five years elapsed between measurement occasions, whereas, for the centenarians, 20 months. Researchers interested in developmental questions of change over time are encouraged to employ the measurement model verified by this study and to extend this work by carefully considering the time intervals necessary for proximal and distal influences to unfold among older adults.
Third, Social Resources tended to have the lowest loadings per indicator. In this sample, relative to the other indicators, talking on the phone is the main indicator tapping the respondent’s Social Resources. Burholt and colleagues [
Several limitations, however, exist that affect the generalization of this study’s results. First, the participants were Southeastern older adults in reasonably good health, mentally competent, and community-dwelling. Second, the younger age groups (those in their 60s and those in their 80s) were randomly selected by race and gender to approximate older adults in Georgia. However, in contrast, centenarians were selected using convenience sampling through state and local agencies. Also, the sexagenarians and octogenarians were assessed in testing locations; centenarians completed their assessments at home. In addition, for the two younger age groups, measurement occasions were five years apart, but for the centenarians the measurement occasions were approximately 20 months apart. With only two waves of data, longitudinal results are to be interpreted with caution. Future research will want to employ other valid assessments of similar assessments of the five resources for comparison, particularly with larger, more homogeneous samples. This would provide opportunity to compare the relationships between the revised OARS latent resources based on our results and other known measures. Also, using a more homogenous sample of older adults might mitigate some of the methodological difficulties inherent in our heterogeneous sample that includes three age groups of old (60s and 80s) and very old adults (100s).
Finally, the items used for Social Resources in this study could be improved in future research. All the latent variables except Social Resources were fairly consistent across measurement occasions. In fact, for the models tested without the Social Resources latent variable, the overall measurement model fit the data well and factorial invariance of the latent variables over time was substantiated. Future research is encouraged to consider other measures of Social Resources (see [
This study employed data from the Georgia Centenarian Study and used the popular Duke OARS [
Are your assets and financial resources sufficient to meet emergencies? 1 Yes 0 No
Do you usually have enough to buy those little “extras,” that is, those small luxuries? 1 Yes 0 No
At the present time do you feel that you will have enough for your needs in the future? 1 Yes 0 No
Please tell me how well you think you are now doing financially as compared to other people your age—better, about the same, or worse? 3 Better 2 About the same 1 Worse
How well does the amount of money you have take care of your needs—very well, fairly well, or poorly? 3 Very well 2 Fairly well 1 Poorly
Are your expenses so heavy that you cannot meet the payments, or can you barely meet the payments, or are your payments no problem to you? 0 Subject cannot meet payments 1 Subject can barely meet payments 2 Payments are no problem
In general, do you find life exciting, pretty routine, or dull? 2 Exciting 1 Pretty routine 0 Dull
How would you rate your mental or emotional health at the present time—excellent, good, fair, or poor? 3 Excellent 2 Good 1 Fair 0 Poor
Taking everything into consideration how would you describe your satisfaction with life in general at the present time—good, fair, or poor? 2 Good 1 Fair 0 Poor
Can you use the telephone… 2 without help, including looking up numbers and dialing? 1 with some help (can answer phone or dial operator in an emergency, but need a special phone or help in getting the number or dialing)? 0 are you completely unable to use the telephone?
Can you get to places out of walking distance… 2 without help (drive your own car, or travel alone on buses, or taxis)? 1 with some help (need someone to help you or go with you when traveling)? 0 are you unable to travel unless emergency arrangements are made for a specialized vehicle like an ambulance?
Can you go shopping for groceries or clothes (assuming subject has trans.)… 2 without help (taking care of all shopping needs yourself, assuming you had transportation)? 1 with some help (need someone to go with you on all shopping trips)? 0 are you completely unable to do any shopping?
Can you prepare your own meals… 2 without help (plan and cook full meals yourself)? 1 with some help (can prepare some things but unable to cook full meals yourself)? 0 are you completely unable to prepare any meals?
Can you do housework… 2 without help (can clean floors, etc.)? 1 with some help (can do light housework but need help with heavy work)? 0 are you completely unable to do any housework?
Can you handle your own money… 2 without help (write checks, pay bills, etc.)? 1 with some help (manage day-to-day buying but need help with managing your checkbook and paying your bills)? 0 are you completely unable to handle money?
Can you take your own medicine… 2 without help (in the right dose at the right time)? 1 with some help (able to take medicine if someone prepares it for you and/or reminds you to take it)? 0 are you completely unable to take your medicines?
How much do your health troubles stand in the way of your doing the things you want to do—not at all, a little (some), or a great deal? 2 Not at all 1 A little (some) 0 A great deal
How would you rate your overall health at the present time—excellent, good, fair, or poor? 3 Excellent 2 Good 1 Fair 0 Poor
Is your health now better, about the same, or worse than it was five years ago? 2 Better 1 About the same 0 Worse
How many people do you know well enough to visit with in their homes? 3 Five or more 2 Three to four 1 One or two 0 None
About how many times did you talk to someone—friends, relatives, or others—on the telephone in the past week (either you called them or they called you?) (if subject has no phone, question still applies). 3 Once a day or more 2 2–6 times 1 Once 0 Not at all
How many times during the past week did you spend some time with someone who does not live with you, that is, you went to see them or they came to visit you, or you went out to do things together? 3 Once a day or more 2 2–6 times 1 Once 0 Not at all
This research was supported in part by NIH grant RO1-43435 and PO1 AG17533-01A1.