All patients enrolled in the study, who have eligible study device, signed inform consent, signed HIPAA, and have at least one OptiVol threshold crossing post the start date, were included in this analysis.

There are 3 summary scale scores for the Self-Care of Heart Failure Index (SCHFI) form: self-care maintenance score (Section A), management score (Section B), and confidence score (Section C). Each scale score is standardized to a 0 to 100 range, with 0 indicating the worst and 100 indicating the best performance for each scale score.

Here, changes in each scale score between 6 month follow-up and baseline and between 12 month follow-up and baseline are the secondary outcome measures. Specifically, change at 6 (or 12) month follow-up is calculated as a scale score at 6 (or 12) month follow-up subtracts that at baseline. These changes range from -100 to 100 with 0 indicating no change at all, -100 indicating maximum decrease and 100 indicating maximum increase that is possible from baseline for a self-care scale score.

For each component, the subject needs to have baseline and 6 (or 12) month measurements to calculate the changes. Subjects included for the each component are as following:

Maintenance (or Confidence): 720 and 675 for monthly and quarterly arms at 6 mo, respectively, 640 and 588 at 12 mo. Management, 166 and 141 at 6 mo, 166 and 104 at 12 mo.

The binary outcome of having clinical actions taken (Yes/No) is recorded within one month interval for the monthly review group, and within three months interval for the quarterly review group. To make the endpoints of both groups comparable, data from monthly review group are converted as they were collected quarterly. For example, the month 1, 2 and 3 visits of monthly review group are combined as one visit. If there is at least one action taken in any of these three monthly visits, the action taken variable for the combined visit will be recorded as 'yes'. Unscheduled visits in both groups are lumped to the next quarterly time point.