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Copyright 04-056

Perianal Disease Activity Index (PDAI)

Perianal Crohn’s Disease occurs when there is inflammation at or near the anus, including tags, fissures, fistulae, abscesses or stenosis. Symptoms range from pain, itching, bleeding, discharge, or incontinence of stool.


Troublesome perianal disease occurs in approximately 35% of patients with Crohn’s disease, yet conventional disease activity indices do not reflect the severity of this feature. To address this issue, Dr. Jan Irvine, an experienced gastroenterologist and clinical investigator at McMaster University, developed the Perianal Disease Activity Index (PDAI).

This instrument quantifies disease severity, has acceptable measurement variation and is able to detect important changes in perianal activity status. The PDAI was validated against physician and patient global assessments, serving as the gold standard for evaluating perianal disease.

PDAI uses a simple five-point index, which is easy to administer in a variety of settings. It has been licensed out worldwide and 31 validated translations are now available. The PDAI is utilized in academic research to monitor patients in clinical trials and observational studies. It can also be used to track the progress of patients in practice settings.

To meet increasing demand for electronic versions of questionnaires, the PDAI is available in electronic format as well as in hardcopy. MILO is working closely with translation companies to review electronic conversions of all questionnaires in its library. MILO is also continuing to increase the portfolio of validated translations for questionnaires.

Therapeutic Areas

  • Perianal disease
  • Crohn’s disease
  • Perianal fistulas


  • Academic studies
  • Observational studies
  • Clinical trials


  • 31 Validated translations
  • Use in hardcopy or electronic


MILO Business Development

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