Validating a protein screening test for the Finnish oldest-olds

Abstract Background The population of older adults (≥65 years), especially the subgroup of oldest-olds (≥80 years), is growing rapidly. Despite the importance of adequate intake, protein intake is often suboptimal. There is a need for a simple, efficient and feasible protein-specific dietary assessment tool. Thus, a novel protein screening test adapted to the Finnish cultural context was developed. Aims The aim of this study was to validate a novel protein screening test against a 1-day food record among Finnish older adults, specifically in the community-dwelling oldest-old population. Participants and methods Data were collected as part of the Helsinki Aging Study. The sample (N = 140) consisted of Finnish community-dwelling oldest-old individuals (80 to 100+ years) with sufficient cognitive ability to complete at-home dietary assessment. A 1-day food record and the protein screening test were completed on one habitual eating day. Validity of the protein screening test was assessed using the food record as the reference method, with inadequate protein intake defined as < 1.2 g/kg body weight per day. Results A Bland-Altman plot and concordance correlation coefficient (0.87, 95% CI: 0.83-0.91) demonstrated good agreement between the methods. Sensitivity (0.85, 95% CI: 0.72-0.94), specificity (0.81, 95% CI: 0.71-0.88), area under the receiver operating characteristic curve (0.90, 95% CI: 0.85-0.95), and positive likelihood ratio (4.40, 95% CI: 2.86-6.77) indicated strong diagnostic performance of the protein screening test. An optimal cut-off point for the screening test to identify inadequate protein intake (<1.00 g/kg body weight) was determined. Conclusions The novel protein screening test shows good validity in identifying Finnish community-dwelling oldest-olds with inadequate protein intake. It shows diagnostic potential, given the importance of preventing adverse health outcomes related to suboptimal intake. Key messages • The novel protein screening test shows good validity in identifying Finnish community-dwelling oldest-olds with inadequate protein intake. • The novel protein screening test shows diagnostic potential, given the importance of preventing adverse health outcomes related to suboptimal intake.