Purpose: This study investigated the reasons why cases of one of the most common low-risk gastroenteric diseases, Campylobacter, did not return their questionnaires and whether there were missed opportunities for public health interventions.
Methods: Clients reported between April 3 and November 5, 2012 with a confirmed Campylobacter illness and who did not respond within 30 days after a questionnaire was mailed to them were included. These non-respondents were telephoned, to ask whether they remembered receiving a letter from TPH, the reason why they did not respond, what would have encouraged a response and whether they worked in a sensitive occupation.
Results: A total of 226 Campylobacter cases had not responded during the study period. Of these, 172 (76.1%) were reached by phone and 162 (71.7%) agreed to participate. The age and gender distribution of participants did not differ from cases who responded to the original letter. The largest proportion (54.4%) of participants reported they had forgotten to return the questionnaire. When asked what would have encouraged a response, more information on the importance of returning the questionnaire (19.1%), followed by a simpler form (15.9%) were the most common answers. Only 3 (2.4%) cases were employed in sensitive occupations; none reported working while ill.
Significance: This study validated treating Campylobacter reports as "low-risk" for public health follow-up. Data collected suggest a reminder, simplifying the questionnaire, and underscoring the importance of responding could increase the response rate for letter-based investigations.