The Single Interviewer Approach for Enteric Diseases

Transcription

1 The Single Interviewer Approach for Enteric Diseases Outbreak Management Workshop, September 20, 2013 Joanne Dow, BScN, RN CIC Public Health Nurse, Middlesex London Health Unit Dean Middleton, BSc, DVM, MSc. Senior Public Health Epidemiologist, Enteric, Zoonotic and Vector-Borne Diseases Unit

2 Outline 1. The Single Interviewer Approach (SIA) Health Unit Level Provincial Level 2. The Standardized Questionnaire 3. Online Survey Tools 4. Summary 2

3 What is The Single Interviewer Approach? The administration of questionnaires on cases that occur via one, or a small number, of interviewers Federal Field Epidemiologists use the SIA frequently in investigations Contrast with the Multiple Interviewer Approach Numerous interviewers administering questionnaires The Model in Health Units One interviewer interviews all the cases of one pathogen (e.g., E. coli) 3

4 The SIA in Health Units General Advantages of the SIA include: One interviewer can synthesize all of the information pertaining to the one pathogen within the health unit Surveillance for the pathogen improves within the health unit This assists greatly in early detection of clusters Coordination of a provincial investigation is easier if each health unit has a single investigator with clear responsibility for a pathogen Disadvantages Interviewer focuses on one pathogen only 4

5 Examples from Middlesex-London Health Unit 1999 Local Fair Petting Zoo E. coli O157:H7 Outbreak Four E. coli reports within 10-day period Same Agricultural Pavilion + feeding goats The SIA assisted with identifying the outbreak setting and source Iterative, evolving interview process - hypothesis generation 5

6 Examples from Middlesex-London Health Unit 2005 Salmonella Enteritidis PT13 Mung Bean Sprout Outbreak Three lab-confirmed Salmonella cases reported within a week The SIA assisted with identifying the mung bean sprouts Local becomes Provincial 6

7 Examples from Middlesex-London Health Unit 2007 University Food Court Salmonella Typhimurium PT108 Six verbal reports to the Single Interviewer within an hour The SIA assisted with identifying the outbreak source Multiple SIs became a necessity: volume, urgency Electronic tools: accuracy of data, student buy-in, asynchronous responses, online survey 7

8 The Single Interviewer Approach In Health Units 12 health units are currently using the SIA Different models are used in these health units 8

9 The Single Interviewer Approach at the Provincial Level 9

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11 Outbreak Interviewing S. Heidelberg, By Month, Ontario, Jan Mar. 2012* * As of Mar. 9,

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13 Advantages of the SIA at the Provincial Level Item Questionnaire Data Consistency/Quality/ Comparability Hypothesis Generation Hypothesis Testing Data Analysis Multiple Interviewer Approach 1 or 2 cases in numerous health units leads to inconsistencies. Potential hypotheses not discussed among all of the interviewers. Inability to quickly respond to items identified as highly suspected to be the source of the outbreak. Primarily running frequencies of closed ended questions. Single Interviewer Approach Better data consistency and comparability. Every case given priority. 1 or 2 interviewers synthesize all information gathered to generate hypotheses. Can explore the hypotheses on the very next interview. 1 or 2 interviewers synthesize the open ended question data better. 13

14 The Single Interviewer Approach Provincial Outbreaks Beneficial for certain provincial outbreaks These outbreaks would primarily include those where it is suspected that a food item is being distributed to two or more health units 14

15 What is the Numbers Impact of Provincial Outbreaks? Number of enteric ESDs Number of ESDs that could have used SIA 5 5 Number of cases involved with the SIA * Total number of enteric cases 8,952 9,022 Approximate percent of total enteric cases 2.9% 7.8% * * The S. Enteritidis case-control study is included in these numbers. An ESD was not issued for this investigation. The investigation included 630/9,022 = 7.0% of enteric cases. Source: iphis weekly and monthly reports. 15

16 Case and Contact Management for a Provincial Outbreak HU s contact case. Inform the case that they may be contacted again if they are identified as being part of an outbreak HU s enter the case s contact information (e.g., phone number) in iphis The single interviewer contacts the case 2-3 days later, after the appropriate laboratory typing/ subtyping findings identify that the case is included in the outbreak 16

17 Adopting the Single Interviewer Approach The SIA Working Group supports adopting the SIA Representation from 10 health units Use of the Single Interviewer Approach as a Best Practice for Investigation of Enteric Diseases in Ontario document. The work of the Standardized Questionnaire Working Group is expected to compliment the SIA 17

18 The SIA Working Group Jurisdiction Name Title TOR Anne Arthur Manager (A), Communicable Diseases Surveillance Unit PTC Edwina Dusome Manager, Infectious Disease Programs MSL Joanne Dow (Co-Chair) Public Health Nurse NIA Heather Hague Manager, Infectious Diseases MOHLTC Melissa Helferty Epidemiologist PHO Christina Lee Senior Public Health Consultant LGL Joan Mays Manager, Community Health Protection PHO Dean Middleton (Co- Chair) Senior Public Health Epidemiologist PHO Stephen Moore Manager, Enteric, Zoonotic and Vector-Borne Diseases Unit YRK Omar Ozaldin Program Manager, Control of Infectious Diseases SUD Cindy Rocca Environmental Support Officer WDG Janice Walters Manager, Control of Infectious Diseases OTT Lindsay Whitmore Epidemiologist 18

19 Enteric Standardized Questionnaire Currently, the 36 health units use different questionnaires Constraints in comparison of questionnaire information between health units Health Unit staff have asked about creating standardized questionnaires 19

20 The Shotgun Questionnaire Originated in the late 1990 s pages 8 point font Mind numbing for the interviewee and interviewer Not likely to obtain accurate information 20

21 What are the Questions on Questionnaires? How to improve a questionnaire to get better information? What is the optimal length? How can the accuracy of the interviewee s answers be improved? How can the flow or the question order be improved? When should the case be allowed to self administer the questionnaire? Is there a need for a standardized questionnaire? How can the transfer of data from the questionnaire to iphis be improved? 21

22 Questionnaire Review Process Literature Review Searched MEDLINE and PsycINFO Example Finding Answers to questions positioned later in the questionnaire were faster, shorter, and more uniform than answers to questions positioned near the beginning (Galesic et al, 2009) 22

23 Jurisdictional Scan Canadian BC CDC C-Enternet PHAC Correctional Services Canada / Canadian Field Epidemiology Program USA US CDC Foodcore Minnesota, Utah, Oregon, Wisconsin Outside of North America OzFoodNet 23

24 The Standardized Questionnaire Working Group Health Unit Name Health Unit Name NWR Sandra Krikke HAL Joanna Oliver SUD Holly Browne WAT Amy MacArthur ALG Gary Leith PTC Edwina Dusome LAM Janet Bowls PEE Liz Haydu OXF Kitty Chan DUR Ross MacEachern MSL Joanne Dow TOR Gemma Vena HUR Erika Clark SMD Jason Riewe GBO Stephanie Nickels HPE Lindsey Bearnes HAM Debra Marsillo LGL Joan Mays NIA Lorrie Ross OTT Melissa Guy WDG Katherine Paphitis PHAC Andrea Nesbitt BRN Rose Corby MOHLTC Melissa Helferty 24

25 Online Survey Tools Web-based data capture Centralized database Entry from multiple sites Entry from multiple users simultaneously Real-time access to questionnaire data Facilitates self-administered questionnaires Particularly useful if contact list available (e.g. event-based outbreaks) 25

26 Online Survey Tools Fluid Surveys Privacy considerations Salmonella Typhimurium phage type 10 February 2013 Outbreak associated with reptiles/feeder mice Post outbreak review focused on use of the online tool 26

27 Summary Single Interviewer Approach Provincial Level Health Unit Level Standardized Questionnaires Online Survey Tools 27