The activities of daily living (ADL) and instrumental activities of daily living (IADL) scales represent fundamental measurements of functional status and are important tools not only for planning and predicting the need for long-term care but also for assessing the effectiveness of various policies and services for older populations. 1) Several studies have confirmed the accuracy, validity, and reliability of these functional scales. However, their accuracy as a measure of functioning may be limited by latent biases stemming from cultural differences in who performs different activities.Gender differences in the ADL and IADL tasks have long been postulated. When asked about items related to performing light housework, doing laundry, and preparing meals, men often report that they do not perform these functions due to gender roles. Lawton 2) recognized traditional gender roles as possible confounders Objectives: Culture-based gender norms regarding who performs daily activities can bias the assessment of instrumental activities of daily living (IADL). This study evaluated item-response biases in the activities of daily living (ADL) and IADL among community-living Korean older adults.
Methods: The subjects included older Korean participants of the Korean Longitudinal Study ofAgeing baseline survey (n=4,164). We performed differential item functioning (DIF) analysis of these data using the Mantel-Haenszel method. Results: We observed different reported levels of disability for eight IADL items among gender, age, and educational level subgroups. After matching for overall functional disability, men were more likely to report limitations in performing various household activities, compared to cognitive activities in women. Conclusions: Cross-national comparisons of ADL and IADL disabilities need to consider item response bias stemming from culture-based gender norms regarding who performs different household activities.