1. A system comprising: a plurality of sensors, each sensor configured to provide a sensor signal that includes physiological information; a processor, communicatively coupled to the sensors, wherein the processor includes: a physiological change event detection module configured to: detect a physiological change event from a sensor signal; and produce an indication of occurrence of one or more physiological change events; and a heart failure (HF) detection module configured to: determine whether the detected physiological change events are indicative of a change in HF status using a first rule: determine whether to override the first rule HF determination using a second rule; and generate an indication of whether the change in HF status occurred according to the first and second rules.