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Task 2.5: Analyze New Data and Suggest Next Steps

You and your colleagues have now been asked to analyze the new line listing in order to determine the next steps in the investigation. For this task, you need to analyze the data provided to you in the line listing. To help with the analysis you’ll also need to update your epi curve and your descriptive epi report.. You then need to consider your options in terms of where the investigation should go next, and come to a consensus as a team as to which avenues to pursue.

The steps below will walk you through this process.

1. Review the email from Dr. Lyons to confirm your understanding of the task.
   
   
2. Download and review the documents attached to Dr. Lyons’ email (Line List v2 and Questionnaire v2 ) both to see what is there and to get a feel for what resources you have available to you in this task.
   
   
   • Please note: In the Line Listings and elsewhere throughout this rotation the "Date" for each patient is listed as a number (e.g., +1 day) rather than an actual date. In a real outbreak investigation the exact date would be provided rather than a number of days. Due to the mechanics of this rotation, the day Ella Cruz became ill is used as the reference point. The "Date" other patients became ill is the number of days before (-) or after (+) the day Ella Cruz became ill.
     
     
   • Each team member should download a copy of these documents and keep his/her own notes. Each of you may notice different things, which will be helpful to share with each other and discuss.
     
     
3. Meet with your team to discuss the task.
   
   
4. Use the Resources link (above) to do additional research as needed throughout the task.
   

Revise Your Hypotheses

In this task you will be reviewing the data in the line listing, revising your epi curve and Descriptive Epi Report, and discussing with your teammates how the new information impacts your thinking about the investigation and the source of the outbreak. As you go through the process and make decisions with your team make sure to keep track of the informal revisions to your hypotheses that arise from the discussion toand record your current thinking about the hypotheses formally.

1. Use the Investigation Status and Plan Template that you used in earlier tasks, update it, and save it under a new name. The ISP your team submitted earlier will have much of the information already in it. You may need to update the columns to reflect the current status of the investigation at the beginning of this task.
   
   
2. The source for your supporting and refuting evidence can be the line listing, the epi curve, the Descriptive Epi Report, or any information that you had about Cocci prior to sending out the questionnaire.
   
   
   • Note all supporting evidence, even if it seems to be balanced by refuting evidence.
     
     
   • Note where supporting evidence is not necessarily clear or valid (e.g., the questionnaire question was not clear).
     
     
   • Any discrepancies between the refuting and supporting evidence can be addressed in the "Data collection and analysis" section, including any questions that are raised, and ways you can go about resolving them.

Analyze Line Listing Data

As in previous tasks, you will use the line listing as both a summary of the cases in the investigation and to help you identify patterns and oddities across the cases. If you have questions as you go through this process, refer back to the example Line Listings in the Resources link (above), and/or revisit the help instructions for task 2.3.

1. Review the hypotheses that are still being considered. Thinking just of these hypotheses:
   
   
   • Does any of the data you see support the ideas you are pursuing for a source for this infection?
     
     
   • Does any of the data you see refute those ideas?
     
     
2. Identify any patterns of response in the line listing data.
   
   
• Is there any question or set of questions that was answered in a similar way by a significant percentage of the case-patient group (more than 2)?
  
  
3. Identify any dead-ends that you can gather from the line listing results. Sometimes knowing where an outbreak isn’t can be just as valuable as knowing where it is.
   
   
   • Is there any question or set of questions that yield no results because you got a lot of negative or non-starter responses?
     
     
   • Is there any question (or set of questions) that has such varied responses that it does not show a pattern or expose any similarities among the case-patients?
     
     
4. Identify any new potential sources of infection from the line listing data.
   
   
   • Are there other potential sources that you see as you review the data that you didn’t identify previously?
     
     
   • Is any data moving in a direction that you hadn’t anticipated, for example toward a specific activity that you hadn’t thought of in your initial brainstorming or first questionnaire?
     
     Tip: Individuals in your team may have considered these factors previously but for one reason or another the information wasn’t included in the team reports. Consider having members of your team look at their individual notes to see if data there is supported by the new information.
     

Update your Descriptive Epi Report (DER)

Use the new data contained in your line list to update your Descriptive Epi Report. Remember this Report will be used as a summary of the important case-patient statistics for your investigation. This will be important as you progress through the investigation process and need to communicate with internal and external audiences.

1. Review examples of “Descriptive Epi Reports” in Resources (above) to remind yourself what information is included in a DER.
   
   
• Make sure to update the information and statistics that you included in your previous DER and to change or add to the report based on the new information you have.
  
  
• Refer to the step-by-step guide in task 2.2 under DER for a reminder of what to include in this report.
  
  
2. Once your team has drafted the report, set it aside in preparation for review with your mentor.
   

Update your Epi Curve

Now that you have 25 cases, you need to update the epi curve to see if the shape of the curve suggests any pattern of spread for an outbreak. Remember that the epi curve visually shows the magnitude of the epidemic over time so it is important to add to it as you receive information about new case-patients. If you have questions as you go through this process, refer back to the example epi curve in the Resources link (above), and/or revisit the help instructions for task 2.3.

1. Open and update the epi curve you created in 2.3. Refer to the Line Listing v2 for the data needed to update the epi curve. Add a box for each new case-patient. Fill in this information along the vertical axis of the table. Use the same format you used previously unless you think changing the format will make the curve more visually accurate. You may need to change the time period on the x-axis if new cases fall outside the current graph.
   
   
2. Summarize the important findings from your analysis of the epi curve in your ISP Template. You’ll need to determine which area(s) to include the findings in.
   

Determine the Next Steps

1. Refer back to the Investigation Process Flow, in the Resources (above) to remind yourself of any protocol to follow in these circumstances.
   
   
2. Discuss all the different potential actions with your team, and come to consensus about how to proceed. Consider next steps in the three areas listed below.
   
   
   • Data collection and analysis: Now that you have collected this information through the questionnaire and done some analysis of that data, what do you think is the best path in order to accurately identify the source of this outbreak?
     
     
   • Hypothesis development and testing: Based on your analysis of the line listing, how have your hypotheses changed? How will you go about exploring those hypotheses?
     
     
   • Management and communication: What data, if any, do you have that you need to share with the medical community? A governing body? The public? The media?
     
     
     • Include groups may need contacted in the future and what information is needed before contacting them to ensure speed once the information becomes available. Waiting until the information is available to plan management and communication could result in unnecessary delays.
       
       
3. Record the plan for each area in the Investigation Status and Plan Template (ISP).
   
   
4. Provide a summary of your thoughts in an email to Dr. Lyons, including the following elements in your response:
   
   
   • Each possible area of action,
     
     
   • Your suggested next steps in relation to that area, and
     
     
   • Your rationale for the actions you have chosen, including where you have decided not to act.
     

Review and submit your work.

1. Review your work.
   
   
   • Did you conduct a thorough analysis of the data that was provided, updating your DER and epi curve accordingly, and account for how the data impacted your original hypotheses?
     
     
   • Did you review all possible avenues of exploration at this juncture, develop a plan to move forward and back it up with sound reasoning in your ISP?
     
     
   • Did you summarize your plan in your email response to Dr. Lyons?
     
     
2. Submit your work.
   
   
   • Review the checklist located in the Submit Your Work section of this task to ensure completion of the task before submitting your deliverables to your mentor.
     
     
   • Please note: Only one set of deliverables need to be submitted per team. Any additional notes not captured in that set of deliverables should be retained by the team members for possible use in future tasks.
     

Cross-Team Conference

During outbreak investigations, investigators are charged to continually apprise their colleagues of any progress that has been made. In the spirit of this tradition, you will have periodic 'cross-team' conferences where one team presents the state of the world and any recommendations made for next steps.

On these “What next?” tasks, all the teams in the cohort meet to have a roundtable discussion of what steps were suggested. One team per conference will be responsible for presenting their thoughts on next steps and strategies.

1. Contact your mentor to determine which team will be presenting in this round.
   
   
   • If your team will be presenting, meet with your teammates briefly to determine how to divide up the presentation of a brief history of the outbreak, and strategies and next steps in each of the three areas (data collection and analysis, hypothesis development and testing, and management and communication). Since you are presenting material you have already been discussing for a substantial period of time, the preparation required should be minimal. Remember: This is intended to be an informal discussion.
     
     
   • If your team will not be presenting, it is still important to review the strategies and next steps you recommended, so as to be ready to give thoughts and feedback to the team who does present.
     
     
2. The presenting team leads the discussion with a brief overview of pertinent facts about the outbreak and the key strategies that they recommended to Dr. Lyons.
   
   
3. The other teams are given an opportunity to respond with thoughts and comments. The discussion is mediated by the mentor.
   
   
4. The mentor summarizes the points made before closing the discussion.

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• Tip: While discussing how the new information affects existing hypthoses informally, taking good notes will help when it comes to formally documenting the supporting and refuting evidence for each hypothesis.

 

• Trap: What looks like a difference at first glance may not be significant upon further analysis. When looking at new data do not accept seeming differences at face value. Keep in mind that if a potential difference falls in a gray zone after analysis, more data can be collected to help determine whether it is significant or not.

 

• Tip: Think about the big picture and not just the current task. Keep in mind where the investigation is and where it needs to go in order to accurately identify the source of the outbreak so the outbreak can be contained. Recommended actions should be directed toward moving the investigation forward in a strategic way.

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Task 2.5 Resources

While Wikipedia is a valuable resource, unlike some other websites anyone can contribute to or modify the site (whether they're knowledgeable about the topic or not). As a result, the site is subject to constant change by questionable sources. Be sure to cross-check information on Wikipedia with other reputable sites to ensure accuracy.

General Resources

Hypotheses and the Scientific Method FAQ
This FAQ supports you in creating and testing scientific hypotheses, with examples and explanations.

Hypotheses for Epidemiology FAQ
General information on hypotheses and testing with emphasis on hypotheses for epidemiology studies.

Medline Plus
A medical dictionary from Medline Plus to help with scientific terms.

Investigation Process Flow
A flowchart that explains the standard procedure that is taken at the CDC during an outbreak investigation.

Epidemiological Curve

Sample EpiCurve
An example of an epi-curve with a one-month time interval. (Note: The difference between colonization and infection is whether the organism is making the person sick at this time.)

Overview of Epi Curves
From the West Virginia Department of Health and Human Resources. The document contains information on how different shapes of epi curves are related to the source of an outbreak as well as examples of epi curves.

Descriptive Epidemiology Report (DER)
The DER contains statistics regarding person, place, and time of current case-patients including the distribution of cases by age group, state of residence, or time/date of illness onset. Much of this information is part of the Line Listing.

Sample DER 1: Hospital Admissions
A descriptive epidemiology report regarding fractures and hospital admissions in Australia. The descriptions, tables, and graphs that begin on page 13 are useful examples.

Sample DER 2: Lyme Disease
A descriptive epidemiology report of Lyme disease in Ontario.

Sample DER 3: E. Coli
A descriptive epidemiology report of an E. coli outbreak.

Sample DER 4: Foodborne outbreak
A report on a food borne outbreak including case definitions, an epi curve, and a descriptive epidemiology report. The DER is in the “Results” section on page 2, and in the “Appendix” on page 4.

Coccidioidomycosis (cocci)

Cocci Overview from CDC
Information from the Centers for Disease Control and Prevention (CDC) on cocci clinical features, transmission, risk groups, challenges, and other important info.

Cocci Overview 1
Includes common symptoms as well as tests and exams to detect the disease.

Cocci Overview 2
Includes x-rays of a cocci patient.

Cocci Overview 3
Includes a map of endemic areas (from Wikipedia).

Cocci Overview 4
Includes incubation periods, clinical signs, and communicability in both humans and animals from The Center for Food Security and Public Health at Iowa State University.