OBJECTIVES: The use of telemonitoring is receiving increased recognition by providers and payers as a means of decreasing healthcare costs while improving or stabilizing patient outcomes. We compared hospitalizations and ER visits for telemonitored patients before and after they began telemonitoring. METHODS: We analyzed 415 CHF patients who were assigned HomMed SentryTM telemonitors, an FDA-approved 510(k) device, between October 1, 2001, and September 30, 2002. Admission and discharge dates from telemonitoring service were compared with standardized home health nursing assessments using the CMS-mandated Outcome and Assessment Information Set (OASIS). Health status of telemonitored patients was compared with 6509 CHF patients from the ASK for Agencies TM research database, representing 218 home health agencies in 44 states. Comparison patients had OASIS assessments during the same study period. Within-patient differences in the rate of hospitalizations and ER visits per 100 days were reported for telemonitored patients before and after telemonitoring. RESULTS: Telemonitored CHF patients were more likely to have poorly controlled CHF symptoms (45%) than non-monitored patients (34%, p < .001), although monitored and non-monitored patients were comparable on age (78.8 vs. 79.2 years, p > .10) and estimated severity of comorbid conditions (4.6 vs. 5.3 on a 0-16 scale, p > .10). Once CHF patients began telemonitoring, the average decrease in hospitalizations was 3.2 admissions per 100 homecare days (t=-1.98, p=.05) and decrease in ER visits was 3.3 admissions per 100 homecare days (t=-1.94, p=.05). CONCLUSIONS: Telemonitors are a valuable tool for improving the functional status and outcomes of homebound CHF patients. That telemonitored CHF patients are more likely than other homebound CHF patients to have poorly controlled symptoms suggests that home health agencies are assigning telemonitors to their most severe patients.