For clinicians: reading a My Flow Check diary

How this data was collected

The diary is a documentation tool, not a diagnostic device. A few design facts help you weigh the record:

• Entries are logged in real time, as each void and drink happens, in the patient's own timezone.
• Data is stored only on the patient's own device. There is no server and no account; the patient decides when to share the export with you.
• Diary days are anchored to the patient's reported bedtimes rather than to midnight, so time spent awake past midnight stays within the correct diary day.
• Day 1 is excluded from the 24-hour volume, nocturnal polyuria index, and average voided volume calculations, since the patient may have started partway through a day.

Reading the report

The PDF export is a seven-page clinical report. Its pages, in order:

1. A combined three-day grid of every logged event.
2. A results overview with the headline metrics.
3. Three per-day pages, one for each diary day.
4. Clinical analysis charts.
5. A machine-readable data page.

The accompanying CSV and FHIR files carry the same data in EMR- and spreadsheet-ready form.

Metric definitions

The report computes the following metrics. These are definitions and computation conventions only.

24-hour voided volume (24HV)

The total urine volume voided across a full 24-hour period.

Nocturnal polyuria index (NPi)

The proportion of the 24-hour voided volume produced overnight, including the first morning void.

Average voided volume (AVV)

The mean volume per void across the measured period.

Maximum voided volume (MVV)

The largest single voided volume recorded during the diary.

Daytime frequency

The number of voids recorded during waking hours, between the first morning void and bedtime.

Nocturia

The number of voids recorded during the night, between bedtime and the first morning void.

Reference ranges follow the ICS standardisation of terminology.