Validation of the GERY Protein Intake Screening Test among community-dwelling oldest-olds in Finland

Protein intake is often suboptimal among older adults, which may lead to protein-energy malnutrition, sarcopenia and frailty. A need exists 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. The aim of this study was to validate a novel protein screening test against a 1-d food record among Finnish older adults. Data were collected as part of the Helsinki Aging Study. The sample (N 140) consisted of Finnish community-dwelling oldest-old individuals (age range 80-100 years) with sufficient cognitive ability for at-home dietary assessment. A 1-d food record and the protein screening test were completed on one habitual eating day. Validity was assessed using the food record as a reference, with suboptimal protein intake defined as <1·2 g/kg BW/d. 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 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 for the screening test to identify suboptimal protein intake was assessed at <1·00 g/kg BW/d. The novel protein screening test has good concurrent validity with the food record in identifying Finnish community-dwelling oldest-olds with suboptimal protein intake. It shows diagnostic potential for identifying individuals with suboptimal intake and to engage in targeted intervention.