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PCDAI Calculator

The score children’s inflammatory bowel disease (IBD) teams use for Crohn’s disease, worked out from the last week, recent blood tests, growth and an examination.

The Paediatric Crohn’s Disease Activity Index (PCDAI) is a score from 0 to 100 that children’s IBD teams use to describe how active Crohn’s disease is in a child or teenager. Higher scores mean more active disease. It is also part of the rules for some funded Crohn’s medicines for children in Australia and New Zealand.

A parent or the young person can answer the questions about the last week: tummy pain, stools (poos), how they are coping with daily life, weight and other symptoms. The blood test results (haematocrit, ESR and albumin) are on a recent lab report. Growth and the examination items come from your child’s IBD team, so the calculator shows the total “so far” until those are filled in.

Work out your PCDAI score

The score’s blood test items use different normal ranges for males and females.

For ages 2 to 19.

Abdominal (tummy) pain in the last week
Stools (poos) in a day, over the last week
How your child has been coping with daily life in the last week
Haematocrit, from a blood test in the last week

It may be printed as Hct, HCT or PCV (packed cell volume). Type it as it’s printed on your report: 0.42 (L/L) and 42 (%) both work.

Points for each result
Aged 10 or under33 or more: 0 points; 28 to under 33: 2.5 points; under 28: 5 points
Girls aged 11 to 1934 or more: 0 points; 29 to under 34: 2.5 points; under 29: 5 points
Boys aged 11 to 1435 or more: 0 points; 30 to under 35: 2.5 points; under 30: 5 points
Boys aged 15 to 1937 or more: 0 points; 32 to under 37: 2.5 points; under 32: 5 points

Figures are in %. For a result in L/L, multiply by 100 (0.42 L/L is 42%).

ESR (erythrocyte sedimentation rate), from a blood test in the last week

Also called the sed rate or sedimentation rate. In mm/h (sometimes printed mm/hr or mm in the first hour), as printed on your report.

Points for each result
Everyoneunder 20: 0 points; 20 to 50: 2.5 points; over 50: 5 points

Figures are in mm/h.

Albumin, from a blood test in the last week

It may be printed as Alb, ALB or serum albumin, usually with the liver function tests (LFTs) or other chemistry results (in the US, the comprehensive metabolic panel). Type it as it’s printed on your report: 35 (g/L) and 3.5 (g/dL) both work.

Points for each result
Everyone3.5 or more: 0 points; over 3 to under 3.5: 5 points; 3 or less: 10 points

Figures are in g/dL. For a result in g/L, divide by 10 (35 g/L is 3.5 g/dL).

Weight
Growth in height, from your child’s growth chart From your IBD team: leave it blank if you don’t know

Countries use different growth charts (for example WHO, CDC or UK-WHO charts), so this item uses the chart your child’s IBD team uses. Centile lines are called percentile lines on some charts, and growth may be given as height velocity (cm a year).

Tummy examination by the doctor From your IBD team: leave it blank if you don’t know
Around the anus (perianal area), checked by the doctor From your IBD team: leave it blank if you don’t know
Other symptoms outside the gut in the last week: fever of 38.5 °C (101.3 °F) or more for 3 days, arthritis, eye inflammation (uveitis), erythema nodosum or pyoderma gangrenosum

How the PCDAI score is used where you live

Australia

In Australia, many medicines are subsidised through the Pharmaceutical Benefits Scheme (PBS). The PBS asks for a PCDAI score when a specialist applies for some subsidised Crohn’s medicines for children and teenagers. For one of them, for example, the PBS rules use a PCDAI of 40 or more to start treatment, or extensive inflammation of the small bowel shown on a scan. Source: PBS: severe Crohn disease in children (item 10413C).

Canada

In Canada, provincial drug plans and private insurers set their own rules for some Crohn’s medicines, and some of them ask your child’s specialist for a disease activity score.

New Zealand

In New Zealand, Pharmac, the government agency that decides which medicines are funded, asks for a Special Authority form for some of them. One of Pharmac’s Special Authority forms, for example, uses a PCDAI of 30 or more to start treatment, and a fall of 10 points or a PCDAI of 15 or less to continue it. Source: Pharmac: Special Authority form SA2183.

United Kingdom

In the UK, your child’s IBD team may use this score, or a similar one, to track how active Crohn’s disease is.

United States

In the US, health insurers set their own rules for approving some Crohn’s medicines, and some ask your child’s doctor for a disease activity score.

Somewhere else

Where you live, your child’s IBD team may use this score, or a similar one, to track how active Crohn’s disease is and when planning treatment.

What the total means

The PCDAI score describes how active Crohn’s disease looks from the answers given. It doesn’t diagnose anything, and your IBD team reads it alongside everything else they know about you.

  • Under 10: the range studies call inactive
  • 10 to 30: the range studies call mild
  • Over 30: the range studies call moderate to severe

Sources