Perceptual and Motor Skills, 1992, 75, 665-666.
O Perceptual and Motor Skills 1992
LONGITUDINAL RELIABILITY O F THE LIFE SATISFACTION I N D E X (SHORT FORM) WITH NURSING HOME RESIDENTS: A CAUTIONARY NOTE ' IVO L. ABRAHAM Center on Aging and Health, Uniuersity of Virginia School of Public Health, Catholic University, Leuuen Strmmary.-We administered the L i e Satisfaction Index (Short Form) 18 times over a 39-wk. period to an initial sample of 76 old, frail, multiply impaired, and depressed nursing home residents participating in a longitudinal quasi-experimental study of the effects of cognitive group interventions on cognition and depression. As no changes over time were observed on the outcome variable of life satisfaction, the stability of the instrument's internal consistency could be examined. Kuder-Richardson KR-20 coefficients ranged from .11 to .60, with a mean of .42 (SD= .11). We conclude that caution should be used when applying this instrument to measure life satisfaction in frail nursing home residents.
The recent emphasis on the quality of life of older adults, especially those in long-term care facilities, has sparked a renewed interest in the concept of life satisfaction and its measurement. Here we report the internal consistency reliabilities of the short version of the Life Satisfaction Index (Wood, Wylie, & Sheafor, 1969) over 18 repeated administrations in a quasiexperimental study involving frail, multiply impaired nursing home residents (Abraham, 1989). Since no significant changes were observed on the outcome variable of life satisfaction across and within subsamples, an investigation of the instrument's longitudinal internal consistency is appropriate as experimental effects can be excluded as source of variation (see also Abraham, 1991, for a related paper on the geriatric depression and hopelessness scales). Method.-Complete descriptions of methods have been presented (Abraham, 1789, 1991). Note that the sample consisted of 76 older adults (17 men and 59 women), residing in seven nursing homes. These subjects constituted a group of frail elderly, of advanced age, including cognitively intact as well as cognitively impaired people, who had been institutionalized for quite some time, who were physically quite ill, and who exhibited mild, moderate, or severe depression. The data reported here were obtained in a quasi-experimental study of the effects of cognitive-behavioral group therapy, focused visual-imagery group therapy, and educational discussion groups on cognition and depres-
'Supported by Grants lROlNR1566 from the National Institutes of Health and l T O l M H l 9362 from the National Institute of Mental Health. Address correspondence to I. L. Abraham, University of Virginia, Center on Aging and Health, Madison House, 170 Rugby Road, Charlottesville, VA 22903.
666
I . L. ABRAHAM
sive symptomatology in nursing home residents. There were 18 time points, spread over 36 weeks, at which the scale was administered. These ranged from the pretreatment period through the treatment period to the posttreatment period. 1 presents the KR-20 estimates for the Results and discunion.-Table scores at each of the 18 time points. Coefficients ranged from .11 to .60. Eight coefficients (44.4%) fell in the .41 to .50 range, four in the .31 to .40 (22.2%) and the .51 to .60 ranges (22.2%), and one in the . l l to .20 (5.6%) and the .21 to .30 (5.6%) ranges. The mean coefficient across the 18 time points was .42 (SD= .11). TABLE 1 KR-20 ESTLMATES AT 18 TIME POINTS(N= 76) Time
KR-20
Time
KR-20
Time
KR-20
I1 [2
.45
17
.36
'I 3
.51
.48
4
.60
114
.46
I>
4
ts
.51
if I
16
.30
!12
.40 .44 .46 .>4
'15
'4
.48 .37
.52 .38 .ll .43
*lo
t16 t17
t18
Mi n Max
M SD
.ll
.60 .42 .11
Clearly, internal consistency estimates were very low across the 18 time points. At 14 time points there was more unreliability for the instrument than reliability, as coefficients were below .50. The fact that the highest coefficient was a marginal .60 further underscores the compromised and inconsistent internal consistency of the scale when used with depressed, frail nursing home residents. While further investigations specifically psychometric in nature are needed, our findings, at least for the time being, are ground for cautioning against the indiscriminate use of the scale to measure life satisfaction in frail, multiply impaired, and depressed nursing home residents. REFERENCES ABRAH~M I. ,L. (1989) Comparative effectiveness of group interventions for depressed elderly in long term care. (Final Report of Grant lROlNR1566) Bethesda, MD: National Center for Nursing Research, National Institutes of Health. ABRAHAM, I. L. (1991) The Geriatric De ression Scale and Hopelessness Index: longitudinal psychometric dara on frail nursing [ome residents. Percepttraf and Motor Skiffs, 72, 875880. Woou, V., WYLIE,M. L . , & SI-IEAFOR, B. (1967) An analysis of a short self-report measure of life satisfaction: correlation with rater judgments. Journal of Gerontology, 24, 465-469.
Accepted
Augiisl 10, 1992.
O Perceptual and Motor Skills 1992
LONGITUDINAL RELIABILITY O F THE LIFE SATISFACTION I N D E X (SHORT FORM) WITH NURSING HOME RESIDENTS: A CAUTIONARY NOTE ' IVO L. ABRAHAM Center on Aging and Health, Uniuersity of Virginia School of Public Health, Catholic University, Leuuen Strmmary.-We administered the L i e Satisfaction Index (Short Form) 18 times over a 39-wk. period to an initial sample of 76 old, frail, multiply impaired, and depressed nursing home residents participating in a longitudinal quasi-experimental study of the effects of cognitive group interventions on cognition and depression. As no changes over time were observed on the outcome variable of life satisfaction, the stability of the instrument's internal consistency could be examined. Kuder-Richardson KR-20 coefficients ranged from .11 to .60, with a mean of .42 (SD= .11). We conclude that caution should be used when applying this instrument to measure life satisfaction in frail nursing home residents.
The recent emphasis on the quality of life of older adults, especially those in long-term care facilities, has sparked a renewed interest in the concept of life satisfaction and its measurement. Here we report the internal consistency reliabilities of the short version of the Life Satisfaction Index (Wood, Wylie, & Sheafor, 1969) over 18 repeated administrations in a quasiexperimental study involving frail, multiply impaired nursing home residents (Abraham, 1989). Since no significant changes were observed on the outcome variable of life satisfaction across and within subsamples, an investigation of the instrument's longitudinal internal consistency is appropriate as experimental effects can be excluded as source of variation (see also Abraham, 1991, for a related paper on the geriatric depression and hopelessness scales). Method.-Complete descriptions of methods have been presented (Abraham, 1789, 1991). Note that the sample consisted of 76 older adults (17 men and 59 women), residing in seven nursing homes. These subjects constituted a group of frail elderly, of advanced age, including cognitively intact as well as cognitively impaired people, who had been institutionalized for quite some time, who were physically quite ill, and who exhibited mild, moderate, or severe depression. The data reported here were obtained in a quasi-experimental study of the effects of cognitive-behavioral group therapy, focused visual-imagery group therapy, and educational discussion groups on cognition and depres-
'Supported by Grants lROlNR1566 from the National Institutes of Health and l T O l M H l 9362 from the National Institute of Mental Health. Address correspondence to I. L. Abraham, University of Virginia, Center on Aging and Health, Madison House, 170 Rugby Road, Charlottesville, VA 22903.
666
I . L. ABRAHAM
sive symptomatology in nursing home residents. There were 18 time points, spread over 36 weeks, at which the scale was administered. These ranged from the pretreatment period through the treatment period to the posttreatment period. 1 presents the KR-20 estimates for the Results and discunion.-Table scores at each of the 18 time points. Coefficients ranged from .11 to .60. Eight coefficients (44.4%) fell in the .41 to .50 range, four in the .31 to .40 (22.2%) and the .51 to .60 ranges (22.2%), and one in the . l l to .20 (5.6%) and the .21 to .30 (5.6%) ranges. The mean coefficient across the 18 time points was .42 (SD= .11). TABLE 1 KR-20 ESTLMATES AT 18 TIME POINTS(N= 76) Time
KR-20
Time
KR-20
Time
KR-20
I1 [2
.45
17
.36
'I 3
.51
.48
4
.60
114
.46
I>
4
ts
.51
if I
16
.30
!12
.40 .44 .46 .>4
'15
'4
.48 .37
.52 .38 .ll .43
*lo
t16 t17
t18
Mi n Max
M SD
.ll
.60 .42 .11
Clearly, internal consistency estimates were very low across the 18 time points. At 14 time points there was more unreliability for the instrument than reliability, as coefficients were below .50. The fact that the highest coefficient was a marginal .60 further underscores the compromised and inconsistent internal consistency of the scale when used with depressed, frail nursing home residents. While further investigations specifically psychometric in nature are needed, our findings, at least for the time being, are ground for cautioning against the indiscriminate use of the scale to measure life satisfaction in frail, multiply impaired, and depressed nursing home residents. REFERENCES ABRAH~M I. ,L. (1989) Comparative effectiveness of group interventions for depressed elderly in long term care. (Final Report of Grant lROlNR1566) Bethesda, MD: National Center for Nursing Research, National Institutes of Health. ABRAHAM, I. L. (1991) The Geriatric De ression Scale and Hopelessness Index: longitudinal psychometric dara on frail nursing [ome residents. Percepttraf and Motor Skiffs, 72, 875880. Woou, V., WYLIE,M. L . , & SI-IEAFOR, B. (1967) An analysis of a short self-report measure of life satisfaction: correlation with rater judgments. Journal of Gerontology, 24, 465-469.
Accepted
Augiisl 10, 1992.
