Public Health Information Network (PHIN) Series II

1. Public Health Information Network (PHIN) Series II Outbreak Investigation Methods: From Mystery to Mastery

3. Access Series Files Onlinehttp://www.vdh.virginia.gov/EPR/Training.asp • Session slides • Session activities (when applicable) • Session evaluation forms • Speaker biographies Alternate Web site:http://www.sph.unc.edu/nccphp/phtin/index.htm

4. Site Sign-in Sheet Please submit your site sign-in sheet and session evaluation forms to: Suzi Silverstein Director, Education and Training Emergency Preparedness & Response Programs FAX: (804) 225 - 3888

5. Series IISession V “Interviewing Techniques”

6. Series II Sessions

7. CDCOutbreak Management System Software Support: National Center for Public Health Informatics outbreakms@cdc.gov / (800) 532-9929, option 6

8. OMS Applications • Track demographics, case investigations, and exposure contact relationships for persons, animals, events, travel events, vehicles, objects, organizations, other organisms, and locations. • Create household, social, or occupational relationships among records • Run OMS on desktops or laptops [CAPI]

9. OMS User Interface Source: http://www.cdc.gov/phin/software-solutions/oms/index.html

10. OMS User Interface Source: http://www.cdc.gov/phin/software-solutions/oms/index.html

11. OMS in Virginia Contact: Michael A. Coletta, MPH Bioterrorism Surveillance Coordinator Division of Surveillance and Investigation Office of Epidemiology Telephone: (804) 864-8099 Email: michael.coletta@vdh.virginia.gov

12. Today’s Presenters Aaron Wendelboe, MSPH Doctoral Candidate and Graduate Research Assistant, NC Center for Public Health Preparedness Erin Rothney, MPH Research Associate, NC Center for Public Health Preparedness

13. “Interviewing Techniques” Learning Objectives Upon completion of this session, you will: • Recognize the interrelatedness of interview techniques and questionnaire design • Understand key survey research terms • Understand the advantages and disadvantages of face-to-face, telephone, and computer assisted interview methods

14. Learning Objectives (cont’d.) • Understand the advantages and disadvantages of mail and Web-based survey implementation • Know what to address in interviewer training • Recognize good interview techniques • Understand confidentiality concerns from the perspectives of both the respondent and the outbreak investigator

15. Lecturer Aaron Wendelboe, MSPH Doctoral Candidate and Graduate Research Assistant, NC Center for Public Health Preparedness

16. Basic Steps of an Outbreak Investigation • Verify the diagnosis and confirm the outbreak • Define a case and conduct case finding • Tabulate and orient data: time, place, person • Take immediate control measures • Formulate and test hypothesis • Plan and execute additional studies • Implement and evaluate control measures • Communicate findings

17. Interviewing Techniques Introduction

18. Introduction • The role of interviews in outbreak investigations • Types of interviewing methods • Interrelatedness of interview method and questionnaire design • Key survey research concepts • Sampling • Response rates

19. Role of Interviews in Outbreak Investigations Primary purpose: data collection • Case identification • Risk factor identification • Hypothesis generation

20. Interviewing Methods • Interviewer Administered • Face-to-face • Telephone • Self Administered • Mail-out • Email • Web-based • Combination of 1 and 2

21. Questionnaire Design Interview Method Influenced by: • Length and format of questionnaire • Question types used in a survey • Cost considerations for survey implementation

22. Sampling

23. Sampling Sampling is the systematic selection of a portion of the larger source population. A sample should be representative of the larger source population.

24. Sampling Source Pop: Students (12,000) Sampled pop (150 students)

25. Sampling Why Sample? Because it is more efficient – saves time and money!

26. Sampling Sample size Is the purpose of the study to determine the source of the outbreak? • A small number of cases and controls can reveal risk factors for infection. Is the purpose of the study to determine the number of persons who become sick over a specific period of time [attack rate]? • A cohort study would require a larger sample.

27. Sampling Types of Sampling Simple Random Sample (SRS) Randomly select persons to participate in study. There are many variations of SRS. Convenience Sample Choose those individuals who are easily accessible.

28. Sampling Problems with Convenience Sampling • Based on subjective judgment • Cases may or may not be representative of the total population • May lead to biased results

29. Sampling Additional Resources: http://www.sph.unc.edu/nccphp/training/all_trainings/at_sampl.htm • “Sampling Case Studies” • “Survey Sampling: Precision, Sample Size, and Conducting a Survey” • “Survey Sampling Terminology and Methods”

30. Response Rates

31. Response Rates Response rates measure the percentage of your sample that has participated in your survey. Example: Using the campus directory, you email a survey to a random sample of 100 freshmen. 40 of those students complete the survey and return it electronically. Your response rate is 40%.

32. Response Rates High response rates ensure that survey data are representative of the source population, and that results will be valid.

33. Response Rates Types of Non-response • Non-contact: No one at home • Refusal to participate • Inability to participate (due to language barrier or physical or mental condition)

34. Response Rates What is an average response rate?

35. Response Rates Determining Response Rates Refer to the American Association of Public Opinion Research website: www.aapor.org • Link to the document titled, “Standard definitions” from the home page.

36. Interviewer AdministeredData Collection Considerations

37. Interviewer Administered Data Collection • Advantages and disadvantages of face-to-face interviews • Advantages and disadvantages of telephone interviews • Advantages and disadvantagesof Computer assisted interviews

38. Face-to-Face Interview Advantages: • Higher response rate • Longer survey instrument • Can have more complex skip patterns • More accurate recording of responses • Less item non-response • Appropriate for hard to reach populations (e.g., illiterate, institutionalized)

39. Face-to-Face Interview Disadvantages: • Costly • Potential for interviewer error • Less anonymous than self-administered • Potential for dishonesty

40. Telephone Interview Advantages: • Less costly than face-to-face • Higher response rates than mailed • Quicker access to participants • Supervision of interviewers feasible • Can collect more sensitive information • Survey design can be more efficient

41. Telephone Interview Disadvantages: • Lower response rates than face-to-face • Shorter questionnaires used • Unable to capture important visual information (e.g., rash, working conditions) • Under-coverage (e.g., population without phones) • 2.1% of total population in Virginia

42. Computer Assisted Interviewing (CAI) • CATI – Telephone • CAPI – Personal • ACASI – Audio

43. CAPI Example:NC PHRST Teams NC PHRST Team public health professionals use PDAs* for rapid needs assessment face-to-face interviews. * PDA: Personal Digital Assistant, also sometimes called hand-held computers, palmtops, and pocket computers

44. Field Data Collection EPI Info GIS Wireless: WIFI 802.11 or Bluetooth Field Team 4 Field Team 5 Field Team 1 Field Team 2 Field Team 3 Field data collection using IPAQ Pocket PCs equipped with GPS, GIS software and data collection forms.

47. Pros: Inexpensive No special skills required for data recording Cons: Requires double data-entry Greater risk of data errors Clipboard and paper more cumbersome in the field Pros: Eliminates double data entry Provides routing and direction-finding for field teams Improved randomization through GIS Ability to quickly analyze and map data Cons: Technology is expensive Learning curve / required training for data entry Small screen size requires scrolling through many questionnaire pages vs.

48. For More Information. . . Steven Ramsey, RS Team Leader / Industrial Hygienist PHRST-5 Guilford County Health Department, NC (336) -641-8192

49. Self AdministeredData Collection Considerations

50. Self-administeredData Collection • Advantages and disadvantages of mailed questionnaires • Advantages and disadvantages of Web-based questionnaires