Noninvasive telephone monitoring after hospital discharge has had mixed results in different subgroups of people who have heart failure. Researchers conducted a secondary analysis of data from a multisite study to determine whether the association between postdischarge noninvasive telephone monitoring and nurse telephone coaching (NTM-NTC) differs in patients who have heart failure and different comorbidity burdens, and whether comorbidity burden could help identify patients who may benefit from this approach.

In the original study, patients ages 50 years or older who were admitted for acute decompensated heart failure were randomized to postdischarge NTM-NTC or usual care. A total of 1,313 patients with complete comorbidity data were included in the secondary analysis.

Patients had a mean of 5.7 comorbidities and were classified into low, moderate, or high comorbidity subgroups. Readmission rates at 30 and 180 days weren't significantly different between the intervention and control groups. There was, however, a significant interaction effect between comorbidity burden and NTM-NTC on the mean number of days alive and days alive and out of the hospital. Patients in the high comorbidity subgroup who received NTM-NTC had significantly more days alive and more days alive and out of the hospital than those who received usual care. In contrast, no significant differences between intervention and control groups were found within the low and moderate comorbidity subgroups. Within the high comorbidity subgroup, the risk of death was 50% lower in the NTM-NTC group than in the usual care group, with the survival curve closely resembling that of the low and moderate comorbidity subgroups.

The authors point out that because the study included a subsample of patients with complete data, bias due to missing data may have been introduced.