Event rate assessment

Abstract

This document discusses, among other things, systems and methods to determine an alert state for a patient using received physiologic information, determine an event rate for the alert state, and adjust determination of a composite risk for the patient using the determined event rate.

What is claimed is: 
     
         1 . A system, comprising:
 a signal receiver circuit configured to receive physiologic information of a patient;   a risk stratification circuit configured to determine a composite risk for the patient using a combination of signal metrics, the composite risk indicative of a risk of the patient to develop a heart failure (HF) decompensation event; and   a risk assessment circuit configured to:
 determine an alert state for the patient using the received physiologic information; 
 receive an indication of an occurrence of a HF event for the patient; 
 determine a HF event rate for the alert state, the HF event rate representing a count of HF events for the alert state per unit time; and 
 adjust the determination of the composite risk for the patient using the determined HF event rate to increase a sensitivity or a specificity of the physiologic information in assessing the risk of the patient to develop the HF decompensation event. 
   
     
     
         2 . The system of  claim 1 , wherein the indication of the occurrence of the HF event for the patient includes an indication of HF treatment to the patient. 
     
     
         3 . The system of  claim 2 , wherein the indication of HF treatment to the patient includes an admission or unscheduled visit into a hospital or clinic for HF treatment or an indication that the patient received HF treatment. 
     
     
         4 . The system of  claim 1 , wherein to adjust the determination of the composite risk for the patient includes to adjust the combination of signal metrics or a weighting of a signal metric of the combination of signal metrics used to determine the composite risk. 
     
     
         5 . The system of  claim 1 , wherein the alert state comprises an IN alert state,
 wherein the risk assessment circuit is configured to adjust the determination of the composite risk for the patient to minimize the occurrence of the IN alert state.   
     
     
         6 . The system of  claim 1 , wherein the received physiologic information includes a sensor input,
 wherein to adjust the determination of the composite risk for the patient includes to adjust the sensor input or a weighting of the sensor input using the determined HF event rate for the alert state.   
     
     
         7 . The system of  claim 1 , wherein the received physiologic information comprises the signal metrics. 
     
     
         8 . The system of  claim 1 , wherein the risk stratification circuit is configured to determine the signal metrics using the received physiological information. 
     
     
         9 . A method, comprising:
 receiving physiologic information of a patients using a signal receiver circuit;   determining, using a risk stratification circuit, a composite risk for the patient using a combination of signal metrics, the composite risk indicative of a risk of the patient to develop a heart failure (HF) decompensation event;   determining, using a risk assessment circuit, an alert state for the patient using the received physiologic information;   receiving, using the risk assessment circuit, an indication of an occurrence of a HF event for the patient;   determining, using the risk assessment circuit, a HF event rate for the alert state, the HF event rate representing a count of HF events for the alert state per unit time; and   adjusting, using the risk assessment circuit, the determination of the composite risk for the patient using the determined HF event rate to increase a sensitivity or a specificity of the physiologic information in assessing the risk of the patient to develop the HF decompensation event.   
     
     
         10 . The method of  claim 9 , wherein the indication of the occurrence of the HF event for the patient includes an indication of HF treatment to the patient. 
     
     
         11 . The method of  claim 10 , wherein the indication of HF treatment to the patient includes an admission or unscheduled visit into a hospital or clinic for HF treatment or an indication that the patient received HF treatment. 
     
     
         12 . The method of  claim 9 , wherein adjusting the determination of the composite risk for the patient includes adjusting the combination of signal metrics or a weighting of a signal metric of the combination of signal metrics used to determine the composite risk. 
     
     
         13 . The method of  claim 9 , wherein the alert state comprises an IN alert state.
 wherein adjusting the determination of the composite risk for the patient includes to minimize the occurrence of the IN alert state.   
     
     
         14 . The method of  claim 9 , wherein the received physiologic information includes a sensor input,
 wherein adjusting the determination of the composite risk for the patient includes adjusting the sensor input or a weighting of the sensor input using the determined HF event rate for the alert state.   
     
     
         15 . The system of  claim 1 , wherein the received physiologic information comprises the signal metrics. 
     
     
         16 . The system of  claim 1 , comprising determining, using the risk stratification circuit, the signal metrics using the received physiological information. 
     
     
         17 . A system, comprising:
 a signal receiver circuit configured to receive physiologic information of a patient;   a risk stratification circuit configured to determine signal metrics of the patient using the received physiologic information and to determine a composite risk of worsening status for the patient using a combination of the determined signal metrics; and   a risk assessment circuit configured to:
 determine an alert state for the patient using the received physiologic information; 
 receive an indication of an occurrence of an adverse medical event for the patient; 
 determine an event rate for the alert state, the event rate representing a count of events for the alert state per unit time; and 
 adjust the determination of the composite risk for the patient using the determined event rate to increase a sensitivity or a specificity of the physiologic information in assessing the risk of worsening status for the patient to experience the adverse medical event. 
   
     
     
         18 . The system of  claim 17 , wherein the indication of the occurrence of the adverse medical event includes information about an unscheduled patient admission or hospitalization or a treatment or intervention associated with the worsening status for the patient. 
     
     
         19 . The system of  claim 17 , wherein the composite risk of worsening status for the patient includes a composite risk indicative of a risk of the patient do develop a HF decompensation event,
 wherein the indication of the occurrence of the adverse medical event for the patient comprises an indication of an occurrence of a HF event for the patient,   wherein the event rate comprises a HF event rate representative of a count of HF events for the alert state per unit time.   
     
     
         20 . The system of  claim 17 , wherein the received physiologic information includes a sensor input,
 wherein to adjust the determination of the composite risk for the patient includes to adjust the sensor input or a weighting of the sensor input using the determined event rate for the alert state.