522134
research-article2014
CRE0010.1177/0269215514522134Clinical RehabilitationKammerlind et al.
CLINICAL REHABILITATION
Article
Test–retest reliability of the Swedish version of the Life-Space Assessment Questionnaire among community-dwelling older adults
Clinical Rehabilitation 2014, Vol. 28(8) 817–823 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0269215514522134 cre.sagepub.com
Ann-Sofi C Kammerlind1,2, Sofi Fristedt3, Marie Ernsth Bravell4 and Eleonor I Fransson5,6
Abstract Objective: To examine the test–retest reliability of the Swedish version of the Life-Space Assessment Questionnaire. Design: Test–retest reliability study. Subjects: A total of 298 community-dwelling subjects between 75 and 90 years of age. Methods: The Life-Space Assessment Questionnaire was translated into Swedish. By personal interviews during home visits and two weeks later by telephone interviews the subjects were asked about their lifespace mobility during the past four weeks, and how often and whether they were independent or needed assistance from another person or equipment to reach different life-space levels. Results: None of the four scoring methods showed significant difference between test sessions. The mean (SD) total scores were 65 (22) and 65 (23) out of the maximum possible score of 120 at the two sessions. High levels were found for independent, assisted, and maximal life-space at both sessions. Intraclass correlation coefficients and weighted Kappa-values between 0.84–0.94 were found for the total score, the independent, and the assisted life-space levels, indicating good to excellent reliability. A lower Kappa-value was observed for the maximal life-space level, mainly owing to skewed distributions. The method error values showed that a change of 10 in the total score and a change of one level in any of the three life-space levels can be considered to indicate a real change in clinical practice. Conclusion: The Swedish version of the Life-Space Assessment Questionnaire can be reliably used among community-dwelling older adults. Keywords Elderly, life space, mobility limitation, outcome assessment, reproducibility of results Received: 30 August 2013; accepted: 9 January 2014
1Futurum
– the Academy for Healthcare, County Council, Jönköping, Sweden 2Department of Medical and Health Sciences, Linköping University, Linköping, Sweden 3Department of Rehabilitation, Jönköping University, Jönköping, Sweden 4Institute of Gerontology, Jönköping University, Jönköping, Sweden
5Department
of Natural Science and Biomedicine, Jönköping University, Jönköping, Sweden 6Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Corresponding author: Ann-Sofi Kammerlind, Futurum – the Academy for Healthcare, Ryhov County Hospital, SE-55185 Jönköping, Sweden. Email: [email protected]
Downloaded from cre.sagepub.com at UCSF LIBRARY & CKM on March 9, 2015
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Clinical Rehabilitation 28(8)
Introduction Mobility is a vitally important activity throughout life. Advanced age carries an increased risk of experiencing decreased mobility, with associated activity limitations and participation restrictions in social events.1,2 The Life-Space Assessment, originally developed by Sawyer Baker and colleagues,3,4 has been used to measure mobility in many different populations, for example community-dwelling older adults,5,6 people with eye diseases,7 wheelchair users,8 power mobility device users,9 older people after hospitalization,10 and palliative care patients.11 The questionnaire has previously been translated, e.g. into French-Canadian,9 Finnish,12 Japanese,13 Spanish,14,15 and Portuguese14 versions. Reliable native language versions are vital to ensure standardized measurements of life-space mobility across settings. The purpose of the present study was to examine the test–retest reliability of the Swedish version of the Life-Space Assessment.
Methods The data were derived from a population-based study of health, functioning, and mobility among older persons in Sweden. The study population was randomly selected from a population register. Men and women, 75, 80, 85, or 90 years old, living in Jönköping County, Sweden, in 2009 and 2010, were eligible. Persons with dementia were excluded. In total, 327 persons participated. The study was approved by the regional ethical committee in Linköping (dnr 225-08). During home visits, trained nurses interviewed the participants using the Life-Space Assessment. Two weeks later, the participants were asked to repeat the questionnaire in a telephone interview conducted by a nurse who was blinded to the responses from the home visit. The present reliability study excluded subjects with no or incomplete test results for either of the two test sessions (n = 22) and subjects living in nursing homes (n = 7), yielding an analytical sample of 298 participants. The Life-Space Assessment includes six levels of life-space, ranging from the person’s bedroom
(life-space 0) to places beyond the person’s hometown (life-space 5) (Appendices 1 and 2, available online).3,16 For each of these six levels, the person is asked how often they have gone to that specific lifespace area during the last four weeks, and whether they did so independently or needed assistance from another person or equipment. A total LifeSpace Assessment score is obtained by multiplying the life-space level reached (1–5) by the value for independence (2, 1.5, or 1), as well as by a value for the frequency of transportations (1–4). The total score can range from 0 (totally confined to bed) to 120 (independent, with daily out-of-town mobility). Moreover, three additional measures of life-space levels can be calculated. The independent life-space level indicates the highest level obtained without any assistance. The assistive life-space level defines the highest level reached with help from equipment but not another person. Finally, the maximal lifespace level indicates the greatest distance travelled irrespective of assistance from equipment and/or another person. These three measures can range from 0 (not leaving the bedroom) to 5 (visiting places outside one’s own town). The translation of the Life-Space Assessment into Swedish was performed following well established methods17 and back-translated by a professional text reviewer. For the total scores, the means, mean difference, and 95% confidence interval (CI) were calculated to enable detection of any systematic change of the mean between the first and second test sessions. For the independent, assistive, and maximal lifespace levels, we calculated the medians, and the first and third quartiles. We evaluated relative reliability for the total score (correlation between the first and second test sessions) using ICC2.1.18 To assess the agreements for the independent, assistive, and maximal life-space levels, we calculated the overall proportions of agreement between the two test sessions. For these variables, we also derived weighted Kappa coefficients using FleissCohen weights. We evaluated absolute reliability (variation between the first and second test session) using the method error (ME) (SD of the difference/√2). ME can serve as useful guidelines for determining what magnitude of change should be
Downloaded from cre.sagepub.com at UCSF LIBRARY & CKM on March 9, 2015
819
Kammerlind et al. Table 1. Characteristics of study participants (n = 298). Variable
Sex, n (%) Males Females Age, years, mean (SD) Marital status, n (%) Married Widows/widowers Never been married Divorced Type of housing, n (%) Living in their own house Living in an apartment Type of living area, n (%) Living in town >5000 inhabitants Living in village 200–5000 inhabitants Living in small village
research-article2014
CRE0010.1177/0269215514522134Clinical RehabilitationKammerlind et al.
CLINICAL REHABILITATION
Article
Test–retest reliability of the Swedish version of the Life-Space Assessment Questionnaire among community-dwelling older adults
Clinical Rehabilitation 2014, Vol. 28(8) 817–823 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0269215514522134 cre.sagepub.com
Ann-Sofi C Kammerlind1,2, Sofi Fristedt3, Marie Ernsth Bravell4 and Eleonor I Fransson5,6
Abstract Objective: To examine the test–retest reliability of the Swedish version of the Life-Space Assessment Questionnaire. Design: Test–retest reliability study. Subjects: A total of 298 community-dwelling subjects between 75 and 90 years of age. Methods: The Life-Space Assessment Questionnaire was translated into Swedish. By personal interviews during home visits and two weeks later by telephone interviews the subjects were asked about their lifespace mobility during the past four weeks, and how often and whether they were independent or needed assistance from another person or equipment to reach different life-space levels. Results: None of the four scoring methods showed significant difference between test sessions. The mean (SD) total scores were 65 (22) and 65 (23) out of the maximum possible score of 120 at the two sessions. High levels were found for independent, assisted, and maximal life-space at both sessions. Intraclass correlation coefficients and weighted Kappa-values between 0.84–0.94 were found for the total score, the independent, and the assisted life-space levels, indicating good to excellent reliability. A lower Kappa-value was observed for the maximal life-space level, mainly owing to skewed distributions. The method error values showed that a change of 10 in the total score and a change of one level in any of the three life-space levels can be considered to indicate a real change in clinical practice. Conclusion: The Swedish version of the Life-Space Assessment Questionnaire can be reliably used among community-dwelling older adults. Keywords Elderly, life space, mobility limitation, outcome assessment, reproducibility of results Received: 30 August 2013; accepted: 9 January 2014
1Futurum
– the Academy for Healthcare, County Council, Jönköping, Sweden 2Department of Medical and Health Sciences, Linköping University, Linköping, Sweden 3Department of Rehabilitation, Jönköping University, Jönköping, Sweden 4Institute of Gerontology, Jönköping University, Jönköping, Sweden
5Department
of Natural Science and Biomedicine, Jönköping University, Jönköping, Sweden 6Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Corresponding author: Ann-Sofi Kammerlind, Futurum – the Academy for Healthcare, Ryhov County Hospital, SE-55185 Jönköping, Sweden. Email: [email protected]
Downloaded from cre.sagepub.com at UCSF LIBRARY & CKM on March 9, 2015
818
Clinical Rehabilitation 28(8)
Introduction Mobility is a vitally important activity throughout life. Advanced age carries an increased risk of experiencing decreased mobility, with associated activity limitations and participation restrictions in social events.1,2 The Life-Space Assessment, originally developed by Sawyer Baker and colleagues,3,4 has been used to measure mobility in many different populations, for example community-dwelling older adults,5,6 people with eye diseases,7 wheelchair users,8 power mobility device users,9 older people after hospitalization,10 and palliative care patients.11 The questionnaire has previously been translated, e.g. into French-Canadian,9 Finnish,12 Japanese,13 Spanish,14,15 and Portuguese14 versions. Reliable native language versions are vital to ensure standardized measurements of life-space mobility across settings. The purpose of the present study was to examine the test–retest reliability of the Swedish version of the Life-Space Assessment.
Methods The data were derived from a population-based study of health, functioning, and mobility among older persons in Sweden. The study population was randomly selected from a population register. Men and women, 75, 80, 85, or 90 years old, living in Jönköping County, Sweden, in 2009 and 2010, were eligible. Persons with dementia were excluded. In total, 327 persons participated. The study was approved by the regional ethical committee in Linköping (dnr 225-08). During home visits, trained nurses interviewed the participants using the Life-Space Assessment. Two weeks later, the participants were asked to repeat the questionnaire in a telephone interview conducted by a nurse who was blinded to the responses from the home visit. The present reliability study excluded subjects with no or incomplete test results for either of the two test sessions (n = 22) and subjects living in nursing homes (n = 7), yielding an analytical sample of 298 participants. The Life-Space Assessment includes six levels of life-space, ranging from the person’s bedroom
(life-space 0) to places beyond the person’s hometown (life-space 5) (Appendices 1 and 2, available online).3,16 For each of these six levels, the person is asked how often they have gone to that specific lifespace area during the last four weeks, and whether they did so independently or needed assistance from another person or equipment. A total LifeSpace Assessment score is obtained by multiplying the life-space level reached (1–5) by the value for independence (2, 1.5, or 1), as well as by a value for the frequency of transportations (1–4). The total score can range from 0 (totally confined to bed) to 120 (independent, with daily out-of-town mobility). Moreover, three additional measures of life-space levels can be calculated. The independent life-space level indicates the highest level obtained without any assistance. The assistive life-space level defines the highest level reached with help from equipment but not another person. Finally, the maximal lifespace level indicates the greatest distance travelled irrespective of assistance from equipment and/or another person. These three measures can range from 0 (not leaving the bedroom) to 5 (visiting places outside one’s own town). The translation of the Life-Space Assessment into Swedish was performed following well established methods17 and back-translated by a professional text reviewer. For the total scores, the means, mean difference, and 95% confidence interval (CI) were calculated to enable detection of any systematic change of the mean between the first and second test sessions. For the independent, assistive, and maximal lifespace levels, we calculated the medians, and the first and third quartiles. We evaluated relative reliability for the total score (correlation between the first and second test sessions) using ICC2.1.18 To assess the agreements for the independent, assistive, and maximal life-space levels, we calculated the overall proportions of agreement between the two test sessions. For these variables, we also derived weighted Kappa coefficients using FleissCohen weights. We evaluated absolute reliability (variation between the first and second test session) using the method error (ME) (SD of the difference/√2). ME can serve as useful guidelines for determining what magnitude of change should be
Downloaded from cre.sagepub.com at UCSF LIBRARY & CKM on March 9, 2015
819
Kammerlind et al. Table 1. Characteristics of study participants (n = 298). Variable
Sex, n (%) Males Females Age, years, mean (SD) Marital status, n (%) Married Widows/widowers Never been married Divorced Type of housing, n (%) Living in their own house Living in an apartment Type of living area, n (%) Living in town >5000 inhabitants Living in village 200–5000 inhabitants Living in small village
