PeriodVol

PBAC on Paper vs on Your Phone

Same arithmetic, different failure modes. Which one you should use depends on how you actually behave during a period — not on which is more modern.

The Pictorial Blood Loss Assessment Chart was published in 1990 as a paper form, and that is still how most people meet it: a PDF from a clinic, or a printout from a patient organisation, with a row for each product and a column for each day.

A phone can hold exactly the same tally. Neither version is obviously better. They fail in different places, and the one that suits you depends on what you are actually like at 11pm on day three.

What both are doing

Both are counting the same thing. Each pad or tampon scores by how soaked it is, clots and flooding add their own points, and the whole period adds up to one number. A total of 100 or more is the mark Higham (1990) proposed as suggesting heavy menstrual bleeding.

Nothing about that arithmetic changes on a screen. If a phone gives you a different answer from paper for the same period, one of them recorded something the other missed — usually the paper one, and usually because it was filled in from memory.

The PBAC calculator does this sum in a browser without installing anything, and the printable tally sheet is the paper version of the same table.

Where paper wins

Your clinic may have given you a specific one. Charts differ slightly between versions — what counts as a "large" clot is not identical everywhere. If a haematologist handed you their sheet and expects that sheet back, fill in theirs. A score they cannot place against their own reference is worth less to them.

Nothing to install, nothing to trust. This is not a small point in bleeding-disorder communities. The Hemophilia Federation of America retired its own tracking app in 2022, after the reversal of Roe v. Wade raised concerns among the women using it about menstrual records being sought as evidence. HFA replaced it with downloadable tracking pages, and paper is what they hand out today.

It works with no phone in your hand. A tally sheet on the back of the bathroom door gets marked at the moment you change a product. That is the moment the number is accurate.

Where a phone wins

You are more likely to actually do it. This is the measured difference, not a marketing claim. In a randomised cross-over study of young women tracking their periods both ways (Journal of Pediatric and Adolescent Gynecology, 2017), 80% preferred the app version, and compliance with reporting was higher on the app. Paper diaries are filled in later, and later means from memory.

It does the adding up. Eight days of tallies multiplied by point values and summed by hand is a place to make a mistake, and a mistake near 100 is the one that matters most.

It is harder to lose over five to eight days. A single sheet of paper has to survive a whole period and then the trip to an appointment.

It can carry more than points. A PBAC score is an abstract scale. PeriodVol keeps the same product logging but also estimates the loss in millilitres and marks the 80 ml per-cycle line, so you arrive with a figure clinicians already use rather than a number that needs explaining. How that estimate is derived is written out in the methodology.

What neither one can do

So which one

If this is youUse
A clinic gave you their chartTheirs, on paper
You would rather nothing about your period sits on a devicePaper — print the sheet
You mark things down when they happenEither — paper is fine
You remember at bedtime what happened all dayA phone
You want millilitres, not just pointsA phone
You are scoring two or three cycles to compareA phone, for the adding up alone

The worst option is the one you abandon on day two. If paper is what you will finish, paper is the better tool.

FAQ

Is there an app that does the PBAC score?

Yes. PeriodVol counts the same pads, tampons, clots and flooding you would tally on paper and keeps the running score, alongside an estimate in millilitres. The Hemophilia Federation of America previously offered one as well, but retired it in 2022 and now publishes paper tracking pages instead.

Is a digital PBAC as accurate as the paper chart?

The scoring is identical, so any difference comes from what gets recorded rather than how it is added up. The published comparison found higher compliance and stronger preference for the app version, which points the other way from the usual worry — the risk with paper is what never gets written down.

Can I switch partway through a period?

Yes, as long as nothing gets counted twice. Add the marks already on your sheet into the app for the days that have passed, then carry on. What you must not do is keep both and add the totals together.

Do I need to print anything to use the app?

No. The app is a complete alternative to the sheet. Some people still print one to hand over at an appointment — a page a clinician can hold is easier to discuss than a screen you are scrolling.

PeriodVol — menstrual volume (ml) tracker for heavy bleeding and low iron. The figures here are references for the numbers, not medical advice, and PeriodVol is not a medical device.
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