The goal of this population-based cohort study is to assess the safety of initiating a new outpatient prescription of 50 mg/day of Sertraline, a higher dose, compared to 25 mg/day, a lower dose, in adults aged 65+ with low kidney function. The primary question is whether initiating a new outpatient prescription of a higher dose of Sertraline (50mg/day) compared to a lower dose (25 mg/day) in older adults with low kidney function (an eGFR \<45 mL/min per 1.73 m2, but not receiving dialysis or having a history of kidney transplantation) is associated with a higher 30-day risk. The outcome measured will be a composite of all-cause hospitalization, all-cause emergency department visit, or all-cause mortality.