How old was Mrs. Laronda Bernier at the time of her most recent medical encounter?
how old = SUBTRACT(MIN(encounters.DATE), patients.birthdate); most recent medical encounter refers to MIN(encounters.DATE);
SELECT T2.DATE - T1.birthdate AS age FROM patients AS T1 INNER JOIN encounters AS T2 ON T1.patient = T2.PATIENT WHERE T1.first = 'Laronda' AND T1.last = 'Bernier' ORDER BY T2.DATE DESC LIMIT 1