Measurements of Intrinsic Capacity in Older Adults: A Scoping Review and Quality Assessment

Abstract

Objectives: This review summarizes the measurements of intrinsic capacity in 5 domains across different studies and evaluates the quality of research papers.

Design: Scoping review of papers written in English and Chinese published in peer-reviewed journals.

Setting and participants: The intrinsic capacity of older adults was assessed using the multidomain structure (Cognition, Locomotion, Psychological, Sensory and Vitality) proposed by the World Health Organization.

Methods: We searched PubMed, MEDLINE, and Web of Science for papers in English, and CNKI, CBM for papers written in Chinese published until September 13, 2022. Both cross-sectional and cohort studies of multidomain measurements of intrinsic capacity were included. Three independent reviewers appraised the quality of studies, and Cohen's kappa was calculated to determine interrater reliability. Data were listed by author, year, setting, country, age range and number of participants, measurement and calculation of intrinsic capacity, and data acquisition method.

Results: We included 53 studies. Twenty-one studies were of high quality, 31 studies were of moderate quality, and 1 study was of low quality. Measurements of intrinsic capacity and derivation of the summative index score were heterogeneous. Intrinsic capacity was usually assessed in 4 or 5 domains. Sensory was the most frequently overlooked domain or subdivided into vision and hearing in some studies. Indicators of vitality were the most heterogeneous. We also found consistency in heterogeneous measurements. The most common measurements of cognition, locomotion, and psychological capacity were the Mini-Mental State Examination, Short Physical Performance Battery, and Geriatric Depression Scale respectively. Self-reported questionnaires were commonly adopted in sensory domain. The Mini-Nutritional Assessment and grip strength were the most measured indicators of vitality.

Conclusions and implications: The focus on capacity and disease should be balanced to better promote healthy aging in older adults. Heterogeneity of intrinsic capacity measurements underscores the need for consensus about standardized measurements and calculation procedures.

Keywords: Intrinsic capacity; healthy aging; measurement; older adults; quality assessment; scoping review.