Instrumental Activities of Daily Living Scales to Detect Cognitive Impairment and Dementia in Low- and Middle-Income Countries: A Systematic Review

Background: The largest proportion of people with dementia worldwide live in low- and middle- income countries (LMICs), with dementia prevalence continuing to rise. Assessment and diagnosis of dementia involves identifying the impact of cognitive decline on function, usually measured by instrumental activities of daily living (IADLs). Objective: This review aimed to identify IADL measures which are specifically developed, validated, or adapted for use in LMICs to guide selection of such tools. Methods: A systematic search was conducted (fourteen databases) up to April 2020. Only studies reporting on development, validation, or adaptation of IADL measures for dementia or cognitive impairment among older adults (aged over 50) in LMICs were included. The QUADAS 2 was used to assess quality of diagnostic accuracy studies. Results: 22 papers met inclusion criteria; identifying 19 discrete IADL tools across 11 LMICs. These were either translated from IADL measures used in high-income countries (n = 6), translated and adapted for cultural differences (n = 6), or newly developed for target LMIC populations (n = 7). Seven measures were investigated in multiple studies; overall quality of diagnostic accuracy was moderate to good. Conclusion: Reliability, validity, and accuracy of IADL measures for supporting dementia diagnosis within LMICs was reported. Key components to consider when selecting an IADL tool for such settings were highlighted, including choosing culturally appropriate, time-efficient tools that account for gender- and literacy-bias, and can be conducted by any volunteer with appropriate training. There is a need for greater technical and external validation of IADL tools across different regions, countries, populations, and cultures.

Automated summary

This study identified 19 discrete IADL tools developed, validated, or adapted for use in low- and middle-income countries for older adults with dementia or cognitive impairment. The diagnostic accuracy of these tools was found to be moderate to good, highlighting the importance of considering cultural appropriateness, efficiency, and gender- and literacy-bias when selecting IADL tools for dementia diagnosis in LMICs. There is a need for further technical and external validation of IADL tools across different regions, countries, populations, and cultures.