An assessment of the content and properties of extended and instrumental activities of daily living scales: a systematic review

PurposeWe performed a systematic review to assess the psychometric properties of extended Activities of Daily Living (eADL) scales.Materials and MethodsArticles assessing eADL scales' properties were retrieved by searching multidisciplinary databases, and reference screening. Data on the following properties were extracted: validity, reliability, responsiveness, and internal consistency. The COSMIN (Consensus-based Standards for the selection of health status Measurement Instruments) risk of bias checklists are used to assess the quality of included articles. All aspects were performed by two independent researchers.ResultsOf 245 titles, 26 articles were eligible, comprising 15 different eADL scales. The Lawton scale had the most papers describing properties, while the Performance-based Instrumental Activities of Daily Living received the highest COSMIN rating. Properties most often assessed were convergent validity and reliability, no articles assessed all COSMIN properties. The COSMIN assessment rated 43% of the properties as 'positive', 31% 'doubtful' and 26% 'inadequate'. Only Lawton was assessed in more than one paper, available data suggest that this scale has excellent reliability, construct validity, internal consistency, and medium criterion validity.ConclusionDespite their common use, there are limited data on the properties of eADL scales. Where data are available there are potential methodological issues in the studies.