Elizabeth E Marfeo1, Pengsheng Ni2, Tamra Keeney3, Alan Jette4. 1. Department of Occupational Therapy, Tufts University Graduate School of Arts and Sciences, Medford, Massachusetts. 2. Department of Health Law, Policy & Management, Boston University School of Public Health, Massachusetts. 3. Center for Gerontology and Health Care Research, Brown University School of Public Health, Providence, Rhode Island. 4. Department of Rehabilitation Sciences and Physical Therapy, MGH Institute of Health Professions, Boston, Massachusetts.
Abstract
BACKGROUND AND OBJECTIVES: To better understand the disablement process among older adults, improved measures of activity limitations are needed. Traditional population-level measures lack the ability to distinguish precise gradations of activity limitation and are unable to detect degrees of differences over a wide range of ability levels. Therefore, we used contemporary measurement methods to improve upon current methodologies for characterizing activity limitations within the National Health and Aging Trends Study (NHATS) . RESEARCH DESIGN AND METHODS: We used the NHATS Round 1 cohort to assess the feasibility of constructing an Activity Limitations scale using Rasch item response theory methods. Factor analysis was used to develop the scale from a set of existing items in the NHATS Mobility, Self-Care, and Household Activity domains. Psychometric properties of the scale were evaluated and the scale was used to examine change in activity limitations among the sample from 2011 to 2015. RESULTS: Results supported an 18-item scale (N = 7,609). Rasch infit and outfit statistics were within acceptable range for all items (Cronbach's alpha = 0.95; sample score reliability = 0.83). From 2011 to 2015, 5.88% older adults demonstrated increase in function, 15% showed decrease in function, and 78% of the sample showed no change (did not exceed ± MDC90). DISCUSSION AND IMPLICATIONS: Findings demonstrate that a unidimensional, interval scale of activity limitations can be constructed using traditional survey measures nested within the NHATS. Results revealed concerns regarding ceiling effects within the current self-report items of activity limitations suggesting future work is needed to expand the range of ability currently represented in the NHATS Activity Limitation items.
BACKGROUND AND OBJECTIVES: To better understand the disablement process among older adults, improved measures of activity limitations are needed. Traditional population-level measures lack the ability to distinguish precise gradations of activity limitation and are unable to detect degrees of differences over a wide range of ability levels. Therefore, we used contemporary measurement methods to improve upon current methodologies for characterizing activity limitations within the National Health and Aging Trends Study (NHATS) . RESEARCH DESIGN AND METHODS: We used the NHATS Round 1 cohort to assess the feasibility of constructing an Activity Limitations scale using Rasch item response theory methods. Factor analysis was used to develop the scale from a set of existing items in the NHATS Mobility, Self-Care, and Household Activity domains. Psychometric properties of the scale were evaluated and the scale was used to examine change in activity limitations among the sample from 2011 to 2015. RESULTS: Results supported an 18-item scale (N = 7,609). Rasch infit and outfit statistics were within acceptable range for all items (Cronbach's alpha = 0.95; sample score reliability = 0.83). From 2011 to 2015, 5.88% older adults demonstrated increase in function, 15% showed decrease in function, and 78% of the sample showed no change (did not exceed ± MDC90). DISCUSSION AND IMPLICATIONS: Findings demonstrate that a unidimensional, interval scale of activity limitations can be constructed using traditional survey measures nested within the NHATS. Results revealed concerns regarding ceiling effects within the current self-report items of activity limitations suggesting future work is needed to expand the range of ability currently represented in the NHATS Activity Limitation items.
Authors: Irene G M Wijers; Alba Ayala; Carmen Rodriguez-Blazquez; Angel Rodriguez-Laso; Vicente Rodriguez-Rodriguez; Maria João Forjaz Journal: Gerontologist Date: 2018-09-14
Authors: Elizabeth E Marfeo; Pengsheng Ni; Christine McDonough; Kara Peterik; Molly Marino; Mark Meterko; Elizabeth K Rasch; Leighton Chan; Diane Brandt; Alan M Jette Journal: J Occup Rehabil Date: 2018-03
Authors: Henrica C de Vet; Caroline B Terwee; Raymond W Ostelo; Heleen Beckerman; Dirk L Knol; Lex M Bouter Journal: Health Qual Life Outcomes Date: 2006-08-22 Impact factor: 3.186