Focused questionnaires

You have been asked to create a focused questionnaire for this investigation. The partners on the last OICC call agreed that the questionnaire should “collect detailed information on type, exact product brands, and purchase locations of nuts and seeds; and also collect product details on blueberries”.

Focused questionnaires are always investigation-specific, and are employed when hypotheses have been identified that need to be refined.

Question 3-1: What kind information would you need to collect on this focused questionnaire?

  • Information on foods of interest, specifically:
    • Brand and product name
    • Description of packaging (e.g., type (box, plastic clamshell, bulk, bag), size, weight, colour)
      • If packaging available: UPC code, lot code/best before date
    • Location and date of purchase
      • Purchase records
    • Description of product
      • Fresh or frozen (blueberries)
      • Roasted, raw, salted/unsalted, sliced, whole (nuts)
      • Roasted, raw, powder, sprouted (seeds)
    • Product samples: whether the case still has the product in question and, if yes, whether they are willing to have samples of this product taken from their home
  • Clinical information that is not already available (e.g., hospitalization)

The focused questionnaire used for this investigation can be downloaded here


The focused questionnaire is developed and shared with provincial epidemiologists (Module 3 – Focused questionnaire). They approve the questionnaire and PHAC will begin using it to re-interview new cases, as well as attempt to re-interview older cases again that were cooperative and had good recall to collect more detailed product information.

Additionally, CFIA has requested that local public health authorities collect product samples from cases’ homes wherever possible.

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