Trends of Disability Under Different Measurement Schemes in the Chinese Elderly Population, 2002 to 2008

ADL and IADL indexes, both of which are self-reported limitations on the daily activities, are limited to differentiate the contextual barriers and intrinsic impairment for of disability status in the elderly population. This study examines four types of disability measurements in the Chinese elderly disability trend analysis: 1) the self-reported difficulty in IADL, 2) the self-reported dependency in ADL, 3) the self-evaluated function performance, and 4) the objective performance in function tests. The data are from three waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2002, 2005 and 2008. The results showed contrasting trends under four different measurement schemes. The fact that the trends based on objective performance is reversed in comparison with trends of ADL and IADL suggests that it is likely that the ADL and IADL improvement could be largely due to the changes in the living environment of the elderly instead of the improvement of their body functions. To better understand the source of disability in the elderly population is extremely important for medical interventions, elderly care and public policy development and we call for more attentions to such a measurement problems in the disability trend studies.