Line Listing Lesson

• Objectives:– Create and maintain a line listing– Explain why a line listing is an important part

of an epidemiological investigation– Explain how line listing techniques change

according to the specific outbreak investigation

Introduction: Line Listing

What is a Line Listing

• A line listing is a method of organizing, storing, and analyzing potential cases that appear throughout the investigation.

• A line listing allows information about time, person, and place to be organized and reviewed quickly.

When and Why

Using Line Lists to Plan for the Next Step of an Investigation

• Find missing data• Explore trends

– Gender– Age– Date of Onset– Geographic

location

• Create an Epi curve

Items to Include in a Line Listing• Identifying information

– Full Name or ID number of potential cases• Clinical information

– Symptoms– Date of symptom onset– Date of diagnosis

• Demographic information– Gender, age, race, occupation

• Geographic information– Place of residence, place of work

• Exposure information– Potential sources of disease exposure

• Other items could include:– Dietary habits, sexual behavior, recreational activities, or hobbies

Sources of Information for a Line Listing

• Interview with patients/health care providers• School attendance sheets• Medical records• Business receipts• Party guest lists• Surveys• Questionnaires• Etc…..

Tools Used to Create a Line Listing

• By hand:– Pen and Paper

• Electronically:– Microsoft Excel– Microsoft Access– EpiInfo (www.cdc.gov/epiinfo/index.htm)

How to Make a Line Listing

• Develop a table

• Each row identifies a single case

• Each column describes a variable of interest

• Update the line listing as new information becomes available

• Use abbreviations or codes to keep the line listing simple

Example 1Example Line List for acute Hepatitis A*

        Signs/Symptoms   Labs   Demographics  

Case #

Report Date Onset

Physician Diagnosis N V A F D J HAIgM Other Sex Age

1 10/12/07 10/2/07 Hepatitis A 1 1 1 1 1 1 1Low SGOT M 37

2 10/15/07 10/5/07 Hepatitis A 1 0 1 1 1 1 1 Low Alt M 35

3 10/16/07 10/6/07 Hepatitis A 1 0 1 1 1 1 1Low SGOT M 38

4 10/16/07 10/6/07 NA 0 0 1 0 ? 0 NA NA F 44

5 10/17/07   Hepatitis A 1 1 1 1 0 0 1 Hbs/Ag- M 17

6 10/17/07 10/7/07 Hepatitis A 0 0 1 1 1 1 1 SGOT=24 F 33

N=nausea V=vomiting A=elevated aminotransferase F=fever D=discreet onset J=jaundice HAIgM=hepatitis AIgM antibody

test SGOT=serum glutamic oxaloacetic transaminase ALT=alanine aminotransferase Hbs=hepatitis B surface antigen

1=“yes”, 0=“no”

Dengue Fever Line ListingName Date of

BirthOnset Date

Rash Fever? If yes, temp

Other symptoms

Lab results

Elizabeth Hatch

21 Jun, 1970

July 6 Yes Yes – 39°

Vomiting, muscle aches

Yes

Mary Ridgeway

12 Dec, 1971

July 6 No Yes - 38° Headache, muscle ache

Yes

Stephen Mara

3 Jul, 2004

July 7 Yes No Headache, vomiting

No

Rajnesh Ram 23 Sep, 2000

July 2 Yes No Vomiting Yes

Lauan Korovavala

4 Apr, 1995

July 10 No Yes – 38.5°

Headache No

Example 2

Example 3

Case #

Age Birth Defect Present

Delivery Date

Exposed to

Alcohol

Exposed to

Marijuana

Exposed to

Accutane

Exposed to an STD

Exposed to

Tobacco 1 15 Y 1/01 Y Y Y Y Y 2 16 Y 1/14 N N Y N N 3 14 N 2/02 Y Y N N Y 4 18 Y 3/07 Y Y Y N Y 5 19 N 4/15 Y N N Y Y 6 17 Y 4/20 N Y Y Y N 7 16 Y 5/1 Y N Y N Y 8 15 Y 5/06 N N Y N N 9 20 N 6/02 N Y N N N 10 19 Y 6/20 Y Y N Y Y 11 15 N 7/04 N N Y N N 12 18 N 7/19 N Y Y Y Y 13 16 N 8/01 Y Y N Y Y 14 15 Y 8/05 N N N Y N 15 16 N 9/10 N N N N N 16 16 Y 10/20 Y N Y N Y 17 15 Y 11/25 Y Y N N Y 18 16 N 11/30 Y N N N N 19 20 N 12/10 Y Y N N Y 20 15 N 12/28 Y N N Y Y

Line Listing regarding the Outbreak of Serious Birth Defects, 2002

Conclusion

• Line listing is integral to an outbreak investigation

• Allows investigator to organize, store, and analyze information

• Provides information about the source of the outbreak, the disease involved, and populations most likely to have been affected

• Helps create an epi curve for the outbreak• Line listing is an important skill that can be

applied to a wide range of epidemiological investigations

Question

1. Why is it important to make a line listing? (check all that apply)

a) To organize information coming from different sources

b) To better understand the nature and path of an outbreak

c) To refine a case definition

d) To enable data sharing between different investigators

Answer1. Why is it important to make a line listing?

(check all that apply)a) To organize information coming from different

sourcesb) To better understand the nature and path of an

outbreakc) To refine a case definitiond) To enable data sharing between different

investigators

• Answer: All of the above are reasons why it is important to make a line listing.

Question

2. When would it be appropriate to use an identification (ID) number instead of a full name?

a) When the line listing will only be used internally

b) When the line listing will be shared with other agencies

Answer

2. When would it be appropriate to use an identification (ID) number instead of a full name?

a) When the line listing will only be used internallyb) When the line listing will be shared with other

agencies

• Answer: (b) It is appropriate to use an ID number instead of a full name when the line listing will be shared with other agencies. This is to protect the confidentiality of the case whose information is presented.

Question

3. What are some common sources of information for a line listing?

(check all that apply)a) Patient records

b) School attendance lists

c) Party guest lists

d) Survey data

e) Interviews

Answer

3. What are some common sources of information for a line listing?

(check all that apply)a) Patient recordsb) School attendance listsc) Party guest lists

d) Survey data e) Interviews

• Answer: All of the above are common sources of information for a line listing.

Question

4. In a line listing, the data should be organized with:

a) Individual cases in each column and variables in each row

b) Individual cases in each column and other cases in each row

c) Variables in each column and other variables in each row

d) Individual cases in each row and variables in each column

Answer

4. In a line listing, the data should be organized with:

a) Individual cases in each column and variables in each row

b) Individual cases in each column and other cases in each row

c) Variables in each column and other variables in each row

d) Individual cases in each row and variables in each column

• Answer: (d) In a line listing, the data should be organized with individual cases in each row and variables in each column.

Question

5. To keep line listings simplea) Eliminate variables

b) Include fewer cases

c) Use abbreviations or coding, with accompanying key

Answer5. To keep line listings simple

a) Eliminate variablesb) Include fewer casesc) Use abbreviations or coding, with accompanying key

• Answer: (a,c) To keep line listings simple, use abbreviations or coding, with accompanying key. Some variables may be eliminated as the case definition is further refined, but it may be necessary to keep the line listing broad in the beginning so that potential contributors to the outbreak are not overlooked. As many cases as possible should be included in the line listing to enable better tracing or the disease and to better understand potential sources of the outbreak.

References• Torok, M. and the FOCUS Workgroup. Case

finding and line listing: a guide for investigators. Focus on Field Epidemiology. 1(4):1-6. Available at: http://nccphp.sph.unc.edu/focus/issuelist.htm. Accessed December 5, 2007.

• Nair, Alison. Public health measurement. PowerPoint presentation for the CDC Ambassador Program; June, 2004.