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Evaluation of the late life disability instrument in the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study.

Hsu FC, Rejeski WJ, Ip EH, Katula JA, Fielding R, Jette AM, Studenski SA, Blair SN, Miller ME - Health Qual Life Outcomes (2010)

Bottom Line: Physical activity and successful aging health education interventions were compared after 12-months of follow-up.The factor structure for the limitation domain within the LLDI in the LIFE-P study did not corroborate previous findings.In addition, the personal subscale would benefit from additional research using IRT.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA. fhsu@wfubmc.edu

ABSTRACT

Background: The late life disability instrument (LLDI) was developed to assess limitations in instrumental and management roles using a small and restricted sample. In this paper we examine the measurement properties of the LLDI using data from the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study.

Methods: LIFE-P participants, aged 70-89 years, were at elevated risk of disability. The 424 participants were enrolled at the Cooper Institute, Stanford University, University of Pittsburgh, and Wake Forest University. Physical activity and successful aging health education interventions were compared after 12-months of follow-up. Using factor analysis, we determined whether the LLDI's factor structure was comparable with that reported previously. We further examined how each item related to measured disability using item response theory (IRT).

Results: The factor structure for the limitation domain within the LLDI in the LIFE-P study did not corroborate previous findings. However, the factor structure using the abbreviated version was supported. Social and personal role factors were identified. IRT analysis revealed that each item in the social role factor provided a similar level of information, whereas the items in the personal role factor tended to provide different levels of information.

Conclusions: Within the context of community-based clinical intervention research in aged populations, an abbreviated version of the LLDI performed better than the full 16-item version. In addition, the personal subscale would benefit from additional research using IRT.

Trial registration: The protocol of LIFE-P is consistent with the principles of the Declaration of Helsinki and is registered at http://www.ClinicalTrials.gov (registration # NCT00116194).

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IRT analysis for personal role factor.
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Figure 2: IRT analysis for personal role factor.

Mentions: IRT was subsequently used to empirically assess the relation between the factor and each of the four items (abbreviated version) that loaded highly on the specific factor at month 12 in the LIFE-P participants. Results from this analysis are presented in Figures 1 and 2. The IRT analysis revealed that the level of information provided by each of the four items in the social role factor were consistent (Figure 1), and items in the personal role factor tended to provide different levels of information (Figure 2). For example, the item "take care of local errands" provided high discriminating power and a high level of information at a moderate level of disability, whereas the other three items did not appear to be highly informative across disability levels.


Evaluation of the late life disability instrument in the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study.

Hsu FC, Rejeski WJ, Ip EH, Katula JA, Fielding R, Jette AM, Studenski SA, Blair SN, Miller ME - Health Qual Life Outcomes (2010)

IRT analysis for personal role factor.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2984553&req=5

Figure 2: IRT analysis for personal role factor.
Mentions: IRT was subsequently used to empirically assess the relation between the factor and each of the four items (abbreviated version) that loaded highly on the specific factor at month 12 in the LIFE-P participants. Results from this analysis are presented in Figures 1 and 2. The IRT analysis revealed that the level of information provided by each of the four items in the social role factor were consistent (Figure 1), and items in the personal role factor tended to provide different levels of information (Figure 2). For example, the item "take care of local errands" provided high discriminating power and a high level of information at a moderate level of disability, whereas the other three items did not appear to be highly informative across disability levels.

Bottom Line: Physical activity and successful aging health education interventions were compared after 12-months of follow-up.The factor structure for the limitation domain within the LLDI in the LIFE-P study did not corroborate previous findings.In addition, the personal subscale would benefit from additional research using IRT.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biostatistical Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA. fhsu@wfubmc.edu

ABSTRACT

Background: The late life disability instrument (LLDI) was developed to assess limitations in instrumental and management roles using a small and restricted sample. In this paper we examine the measurement properties of the LLDI using data from the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study.

Methods: LIFE-P participants, aged 70-89 years, were at elevated risk of disability. The 424 participants were enrolled at the Cooper Institute, Stanford University, University of Pittsburgh, and Wake Forest University. Physical activity and successful aging health education interventions were compared after 12-months of follow-up. Using factor analysis, we determined whether the LLDI's factor structure was comparable with that reported previously. We further examined how each item related to measured disability using item response theory (IRT).

Results: The factor structure for the limitation domain within the LLDI in the LIFE-P study did not corroborate previous findings. However, the factor structure using the abbreviated version was supported. Social and personal role factors were identified. IRT analysis revealed that each item in the social role factor provided a similar level of information, whereas the items in the personal role factor tended to provide different levels of information.

Conclusions: Within the context of community-based clinical intervention research in aged populations, an abbreviated version of the LLDI performed better than the full 16-item version. In addition, the personal subscale would benefit from additional research using IRT.

Trial registration: The protocol of LIFE-P is consistent with the principles of the Declaration of Helsinki and is registered at http://www.ClinicalTrials.gov (registration # NCT00116194).

Show MeSH