Xandar Kardian Xandar Kardian Documentation v2.6.7
XANDAR KARDIANFor care teams

Reading the data · plain-language guide

What is POBC?

POBC (Probability of Baseline Change) tells you how unusual a resident's last 24 hours of respiratory and heart rate are for that particular person. This page explains how the number is made, how to read it, and when to be careful with it.

Version 1.0 · 2026-10-21 · Applies to XK300, XK300 Essence, Kardian Health Insights and the Kardian Dashboard

1 · The idea

The same number can mean different things for different people

Fixed limits, such as "alert if respiratory rate goes above 24", treat every resident the same. Most meaningful changes happen well inside those limits. A respiratory rate of 18 can be ordinary for one resident and a clear change for another.

POBC compares each resident only with their own recent history. It asks one question: how likely is it that the last 24 hours came from this person's usual pattern? If the answer is "very unlikely", POBC moves toward +100 or −100.

Respiratory rate over 8 days for two residents Each dot is one resting respiratory rate reading. Both residents average 15.6 breaths per minute over the previous 7 days. Resident A's readings stay in a narrow band; Resident B's spread widely. In the last 24 hours both average about 18. For A that is far outside the usual band and POBC is high; for B it is inside the usual spread and POBC stays low. 12 16 20 Resident A steady: 7-day average 15.6 usual range POBC high 12 16 20 Resident B variable: 7-day average 15.6 usual range POBC low Day −7 Day −6 Day −5 Day −4 Day −3 Day −2 Day −1 Last 24 h Baseline: previous 7 days breaths/min breaths/min
Illustrative data. Each dot is one resting reading; the sensor collects thousands a day. Both residents average 15.6 breaths per minute over the previous week, and both average about 18 in the last 24 hours. Resident A has been very steady, so 18 is far outside the usual range and POBC is high. Resident B always varies widely, so 18 is ordinary and POBC stays low.

2 · How it is calculated

Last 24 hours against the previous 7 days

1Collect resting readings

The sensor records respiratory and heart rate thousands of times a day, but only when the person is still and the reading is stable. Movement and noisy moments are left out.

2Build the baseline

The previous 7 days of readings form the resident's own baseline: not just the average, but how widely the values usually spread.

3Compare the last 24 hours

The last 24 hours are compared with that baseline. The more unusual they are for this person, the further POBC moves from 0.

Respiratory rate and heart rate each get their own POBC. They are calculated separately and can move independently.

Earlier name

POBC was first called the PoC score (Probability of Change). It is the same measure. The Kardian Dashboard's Detailed Analysis tab still shows the old name.

3 · Reading the score

Direction and size

The POBC scale POBC runs from −100 to +100. Zero means the same as usual. Values at or beyond −80 or +80 fall in the default alarm zone. Examples: −86 is an alarm for a fall, +12 is ordinary, +92 is an alarm for a rise. −100 −80 −50 0 +50 +80 +100 Alarm zone Alarm zone Around 0: same as usual ← Lower than usual Higher than usual → −86 · alarm +12 · ordinary +92 · alarm
The dashed ends are the default alarm zone in Kardian Health Insights (±80). Facilities can change it.
What you seeWhat it means
Sign (+ or −)The direction. Plus means the last 24 hours ran higher than this person's usual; minus means lower.
Size (0 to 100)How unusual the change is for this person. Near 0 is ordinary; near 100 means the recent pattern would be very unlikely if nothing had changed.
±80 or beyondThe default alarm level in Kardian Health Insights. Facilities can change it.

POBC is not a percentage. A score of 90 does not mean "90% chance of illness" or "90% higher than usual". It is a measure of how unusual the change is.

Patterns worth knowing

Several days in a row

Alarms on consecutive days deserve the most attention. A single alarm day is often a passing change, such as a poor night, a drink or a short-lived illness.

A rising trend

Values climbing day after day were more often linked to serious events. Respiratory rate was often the earlier and more telling signal than heart rate.

A falling trend

Also meaningful, but often seen when a resident improves with medication or treatment.

The POBC use cases show 186 real, de-identified examples of what followed a POBC alarm.

In daily use, a facility of 100 residents typically sees about 3 to 5 residents flagged a day, so staff can focus attention where it is most needed. In an independent review in 2024, the Validation Institute found that POBC flagged 75.6% of 201 hospital transfers up to 7 days before they happened. Alarms are also raised for residents who are not transferred. Not every real change ends in a transfer, and some are managed in place.

4 · Where you see it

Daily and real-time POBC

WhereWhat is shown
Insights, resident cardYesterday's 24-hour average respiratory and heart rate, with the POBC value next to each. The day runs 08:00 to 08:00 by default (a facility setting), and the numbers update at about 09:00.
Insights, trend chartThe last 7 days of daily respiratory and heart rate POBC. Days with an alarm are marked with a red dot.
Insights, real-time POBCA continuous version of daily POBC. It looks at the same 24 hours against 7 days, but as a sliding window, so a change can raise an alarm without waiting for the next morning. Recommended at night together with the vacancy alert.
Kardian DashboardPOBC on the resident detail page; the Detailed Analysis tab shows it under its earlier name, PoC score.
APIRespiratory and heart rate POBC values, including an hourly endpoint, for partners who build their own systems. See the API guide.

5 · When to be careful

What can blunt or exaggerate the score

SituationEffect on POBCWhat to do
First 7 daysThere is no baseline yet, so ordinary readings can look unusual. Alarms may be frequent.Expect this after installation or when a new resident is assigned. A new resident always starts a new 7-day learning period.
Few readingsIf the resident spends little time still in the sensor's view, the score has less data and can be blunted or over-sensitive.Check the number of readings shown with the values, and the sensor's position.
Very wide normal rangeIf a resident's values usually swing a lot, only a large change stands out.Know which residents are naturally variable and review their trends directly.
Sudden, acute eventsDaily POBC looks back over 24 hours, so a very sudden change may not show until the next day.Use real-time POBC and the usual real-time alerts when an immediate response is needed.
Not a diagnosis

POBC shows that something has changed for this person. It does not say what has changed or why. It supports the care team's judgement and does not replace a clinical assessment.

6 · Questions

Common questions

The values are in the normal range. Why is POBC high?
Because POBC compares the resident with themselves, not with a population range. A change that is small in absolute terms can be very unusual for a steady resident.
The heart rate looks high. Why is there no POBC alarm?
If the resident's heart rate is usually that high, or usually varies a lot, the reading is not unusual for them. Fixed high and low limits can still be set separately in Insights.
Why so many alarms in the first week?
The baseline needs 7 days of data. Until then, the score has little to compare with.
Can the alarm level be changed?
Yes. ±80 is the default in Kardian Health Insights and can be adjusted in the threshold settings.
Is POBC the same as the PoC score?
Yes. PoC score is the earlier name; the calculation is the same.