Abstract
OBJECTIVE: To evaluate the feasibility of a telephone-based intervention grounded in Peplau's Interpersonal Relations Theory for the management of anxiety among users of Primary Health Care. METHOD: A quasi-experimental, single-arm, before-and-after study was conducted in four Primary Health Care units in the city of São Paulo, Brazil, between January and November 2021. Feasibility was assessed across four domains: demand, acceptability, implementation, and practicality. The Interpersonal Relations Theory for the management of anxiety telephonebased intervention and its preliminary effectiveness was analyzed using a linear mixed-effects model. RESULTS: A total of 1,327 adults were recruited, of whom 1,171 presented moderate to severe anxiety levels, identified through the State-Trait Anxiety Inventory - Six-Item Short Form. High demand (88.2%) and good acceptability were observed, with 69.8% of participants completing follow-up. A significant reduction was found in mean anxiety scores immediately after the intervention (p < 0.001). CONCLUSION: The telephone-based intervention demonstrated feasibility in terms of demand, acceptability, implementation, and practicality, positioning itself as a promising strategy to expand access to mental health care in Primary Health Care.