- Arm I: PCPs are mailed response forms (regarding the disposition of their eligible patients [e.g. patient letter mailed, patient called, scheduled for colonoscopy, colonoscopy completed elsewhere, patient refused procedure, clinical contraindication, patient deceased]) and letters reminding them that their patients are due for a follow-up colonoscopy. PCPs who do not return response forms within 4 weeks are sent a second set of reminders and patient letters.