FreeFrail Project: A Multicomponent Intervention for the Management of Frailty in Primary Care: A Randomized Controlled Trial

The Short Physical Performance Battery (SPPB) is an ordinal quantitative scale ranging from 0 to 12. This validated tool assesses three functional domains: lower-limb muscle strength, by timing the repeated chair-stand test; gait speed, through the 4-meter walking test; and static balance, evaluated with three progressively difficult positions (feet together, semi-tandem, tandem). A composite score is calculated, with lower values reflecting poorer performance. A score of 9 or less has been widely adopted as a cut-off point for identifying frailty and pre-frailty in older adults, making this instrument particularly suitable for evaluating the effectiveness of interventions on physical function

The Mini-Mental State Examination (MMSE) is a continuous quantitative widely used 30-point screening tool validated for older adults to assess global cognitive function. It evaluates orientation, memory, attention, language, and praxis, providing a standardized quantitative measure of cognitive status. Although limited in sensitivity for mild or executive deficits, the MMSE remains a practical first-line assessment in frailty research and clinical protocols, and its integration alongside multidimensional frailty measures allows for a more comprehensive characterization of cognitive vulnerability in aging. A culturally adapted and validated version is available in Spanish, enabling its use in Hispanic populations.

The Frailty-VIG is an ordinal quantitative measure specifically validated for older adults in the community. This multidimensional tool comprises 22 dichotomous items spanning activities of daily living, nutrition, cognition, emotional health, social context, geriatric syndromes, and chronic diseases. By incorporating multimorbidity and psychosocial domains alongside physical aspects, the Frailty-VIG provides a comprehensive assessment of frailty, overcoming the limitations of purely physical indices

will be evaluated with the EuroQoL-5D-5L which generates ordinal categorical variables from five dimensions of health: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is rated on a five-point Likert scale, where higher scores denote lower quality of life. This standardized and validated instrument has been extensively applied in Spanish populations and is particularly appropriate to capture the multidimensional impact of frailty on health-related quality of life

will be assessed using the Spanish validated version of the Pittsburgh Sleep Quality Index (PSQI). This self-administered questionnaire yields a global score between 0 and 21, with higher scores reflecting worse sleep quality. It evaluates seven components-subjective quality, latency, duration, habitual efficiency, disturbances, medication use, and daytime dysfunction. A score above 5 is commonly considered indicative of clinically relevant sleep impairment. As poor sleep has been consistently associated with frailty and functional decline, the PSQI offers a sensitive and appropriate measure for this study

will be assessed through the International Physical Activity Questionnaire (IPAQ), which produces continuous quantitative data expressed in metabolic equivalent task minutes per week (MET-min/week). It includes seven open questions regarding activity over the previous seven days, covering walking, moderate and vigorous activities, and sedentary behaviour. The calculation of MET-min/week allows standardized estimation of global activity levels. This questionnaire is validated and widely used in community-dwelling adults, making it an appropriate measure for capturing the impact of the intervention on activity levels

will be measured with a handheld dynamometer. Results are expressed as continuous quantitative variables in kilograms. Following standardized protocols, participants will be seated with the elbow flexed at 90° and the wrist positioned between neutral and 30° dorsiflexion. They will be instructed to squeeze the dynamometer maximally for 3-5 seconds. Three trials will be performed alternately in each hand, with one-minute rest intervals, and the best value will be recorded. Handgrip strength is a simple, reliable, and validated marker of sarcopenia and frailty risk, strongly correlated with morbidity and mortality in older adults

are strongly supported by the literature in frail population, as these biological factors are fundamentally implicated in the pathways leading to frailty, sarcopenia, and functional impairment. Chronic low-grade inflammation ("inflammaging"), a hallmark of aging, is characterized by increased levels of circulating pro-inflammatory cytokines such as interleukin 6 and 8(IL-6, IL-8), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP). These biomarkers consistently correlate with chronic low-grade inflammation ("inflammaging") and mitochondrial dysfunction (3) they have also been consistently associated with sarcopenia, frailty, and functional decline (4,5) . The blood samples will be analysed at Biomedical Research Institute of Lleida (IRB Lleida), generating continuous quantitative data.