A 78-year-old resident of a care home develops a fever, cough productive of purulent sputum, and confusion over the past 48 hours. On examination, her respiratory rate is 28/min, heart rate 110/min, BP 100/70 mmHg, and temperature 38.5°C. Chest auscultation reveals crackles and bronchial breathing in the right lower lobe. Her CURB-65 score is 3 (Confusion=1, Urea >7mmol/L, RR >=30 or age >=65, BP <90 systolic or <=60 diastolic). According to NICE guidelines, what is the most appropriate initial management setting for this patient?