OBJECTIVE: To examine the measurement equivalence of items on disability across three international surveys of aging. METHOD: Data for persons aged 65 and older were drawn from the Health and Retirement Survey (HRS, n = 10,905), English Longitudinal Study of Aging (ELSA, n = 5,437), and Survey of Health, Ageing and Retirement in Europe (SHARE, n = 13,408). Differential item functioning (DIF) was assessed using item response theory (IRT) methods for activities of daily living (ADL) and instrumental activities of daily living (IADL) items. RESULTS: HRS and SHARE exhibited measurement equivalence, but 6 of 11 items in ELSA demonstrated meaningful DIF. At the scale level, this item-level DIF affected scores reflecting greater disability. IRT methods also spread out score distributions and shifted scores higher (toward greater disability). Results for mean disability differences by demographic characteristics, using original and DIF-adjusted scores, were the same overall but differed for some subgroup comparisons involving ELSA. DISCUSSION: Testing and adjusting for DIF is one means of minimizing measurement error in cross-national survey comparisons. IRT methods were used to evaluate potential measurement bias in disability comparisons across three international surveys of aging. The analysis also suggested DIF was mitigated for scales including both ADL and IADL and that summary indexes (counts of limitations) likely underestimate mean disability in these international populations.
OBJECTIVE: To examine the measurement equivalence of items on disability across three international surveys of aging. METHOD: Data for persons aged 65 and older were drawn from the Health and Retirement Survey (HRS, n = 10,905), English Longitudinal Study of Aging (ELSA, n = 5,437), and Survey of Health, Ageing and Retirement in Europe (SHARE, n = 13,408). Differential item functioning (DIF) was assessed using item response theory (IRT) methods for activities of daily living (ADL) and instrumental activities of daily living (IADL) items. RESULTS:HRS and SHARE exhibited measurement equivalence, but 6 of 11 items in ELSA demonstrated meaningful DIF. At the scale level, this item-level DIF affected scores reflecting greater disability. IRT methods also spread out score distributions and shifted scores higher (toward greater disability). Results for mean disability differences by demographic characteristics, using original and DIF-adjusted scores, were the same overall but differed for some subgroup comparisons involving ELSA. DISCUSSION: Testing and adjusting for DIF is one means of minimizing measurement error in cross-national survey comparisons. IRT methods were used to evaluate potential measurement bias in disability comparisons across three international surveys of aging. The analysis also suggested DIF was mitigated for scales including both ADL and IADL and that summary indexes (counts of limitations) likely underestimate mean disability in these international populations.
Authors: Brian K Chen; Hawre Jalal; Hideki Hashimoto; Sze-Chuan Suen; Karen Eggleston; Michael Hurley; Lena Schoemaker; Jay Bhattacharya Journal: J Econ Ageing Date: 2016-06-23
Authors: K C Prakash; Subas Neupane; Päivi Leino-Arjas; Mikaela B von Bonsdorff; Taina Rantanen; Monika E von Bonsdorff; Jorma Seitsamo; Juhani Ilmarinen; Clas-Håkan Nygård Journal: Int Arch Occup Environ Health Date: 2016-05-04 Impact factor: 3.015
Authors: Aljoscha Landös; Martina von Arx; Boris Cheval; Stefan Sieber; Matthias Kliegel; Rainer Gabriel; Dan Orsholits; Bernadette W A van der Linden; David Blane; Matthieu P Boisgontier; Delphine S Courvoisier; Idris Guessous; Claudine Burton-Jeangros; Stéphane Cullati Journal: Eur J Public Health Date: 2019-02-01 Impact factor: 3.367