June 2008 - EpiData-list - University of Manitoba Mailing Lists

Outbreak analysis diary - Symptoms and Epicurves
by epidata-list＠lists.umanitoba.ca 04 Jun '08

04 Jun '08

Today I am trying to see if I can use Epidata Analysis to do the first three analysis tasks. 1. How many people are sick 2. What is the symptoms profile 3. Epidemic curve Tasks 1 and 2 are nice and easy. a) click Analysis b) Click on Frequency c) Select Sick from the Select Variable Menu d) Tick row percentages I can do the same with the symptoms profile (Diarrhoea, Vomiting etc) What I don't like is the no comes first on the table that is produced, even though it is a Boolean field. What would be on my 'wish list' is if all the symptoms I select could appear in the one table as exposures do when you select outbreak analysis for attack rates Epidemic Curve The epidemic curve starts badly. I start by asking for a histogram of diadate (date of onset of diarrhoea) and even though this is a date field (and shows as dates if I do a frequency) the graph shows 76115, 76116 etc on the X axis instead of 27/05/2008, 28/05/2008. Then I remember there is an 'epicurve' graph and this works well. I would like to be able to show diatime on there as well (time of day people were sick) but remember this is not possible yet. Never mind - dates will do for now. My question for today is - can someone help with some code to create a single onset date? There are two variables - one called diadate and one called vomitdate - the onset date should be whichever one of these is the earliest. We could calculate this manually but it would be great if we could build it in to either epidata (we still have at least 100 records to enter that check code could help with) or epi analysis Thanks Christine Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 >>> <epidata-list-request(a)lists.umanitoba.ca> 27/05/2008 5:04 a.m. >>> Send EpiData-list mailing list submissions to epidata-list(a)lists.umanitoba.ca To subscribe or unsubscribe via the World Wide Web, visit http://lists.umanitoba.ca/mailman/listinfo/epidata-list or, via email, send a message with subject or body 'help' to epidata-list-request(a)lists.umanitoba.ca You can reach the person managing the list at epidata-list-owner(a)lists.umanitoba.ca When replying, please edit your Subject line so it is more specific than "Re: Contents of EpiData-list digest..." -- The information contained in this email and any attachments is confidential and may be legally privileged. If you have received this message in error, please notify the sender immediately and remove all copies of the message, including any attachments. Any views or opinions expressed in this email (unless otherwise stated) may not represent those of Hutt Valley DHB. Thank you. ** Disclaimer added by HVDHB **

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Outbreak analysis with Epidata Analysis diary - 1 Data issues - text to Boolean
by epidata-list＠lists.umanitoba.ca 04 Jun '08

04 Jun '08

We have an outbreak to deal with. Up to several hundred people are possiblly sick after attending a local sports venue that also hosts children's birthday parties. Like many outbreaks it comes at a difficult time (they seem to love happening on Christmas Eve or the day before Easter). This one we learn about the day before a holiday weekend and I have the day off the next day. Someone has designed a questionnaire asking our usual questions (Demographics, symptoms and exposures) and the phone calls have already started. I help someone create an Epidata questionnaire to enter the data and promise to help with the analysis on my return. There are two main things we have to do in our outbreak analysis 1. Describe the pattern of illness by person place and time (how many people are sick with what symptoms, when did they get sick and for how long) 2. Discover if certain 'exposures' - e.g. eating certain foods are associated with illness. Today I come back and find I have a problem I must fix before we start the analysis. My workmate has changed my file so all the Boolean fields I used to record the exposure information are now text fields. (She did this because she wanted to be able to put "U" for unknown. I explain we need the data in Boolean fields for our two by table analysis and if the answer is unknown to leave the field blank. She has entered 66 records already so I have a problem - how do I change the data from text to Boolean as changing a field type in Epidata from text to Boolean would lose all the data? The way I work out is: (using the example outbreak.rec for the file that has data entered as text) 1. Use Save as with outbreak.qes to make a new file called outbreak2.qes. Change this file so the txt fields are now boolean fields 2. Create a new blank rec file from outbreak2.qes called outbreak2.rec 3. Export outbreak.rec to Excel as outbreak2.xls 4. Use search and replace to change the Y, N and U that have been entered to 1,0 and blank 5. Save Outbreak.xls to a text file outbreak2.csv (CSV) 6. Import outbreak2.csv as a text file ticking the option to not use first line. This 'pulls' the data into outbreak2.rec and the boolean fields with the 1 and 0 showing as Yes and No This seems a long way round so maybe someone has a better way to fix this problem? Next posting I will start with the analysis thanks Christine Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 >>> <epidata-list-request(a)lists.umanitoba.ca> 26/05/2008 5:01 a.m. >>> Send EpiData-list mailing list submissions to epidata-list(a)lists.umanitoba.ca To subscribe or unsubscribe via the World Wide Web, visit http://lists.umanitoba.ca/mailman/listinfo/epidata-list or, via email, send a message with subject or body 'help' to epidata-list-request(a)lists.umanitoba.ca You can reach the person managing the list at epidata-list-owner(a)lists.umanitoba.ca When replying, please edit your Subject line so it is more specific than "Re: Contents of EpiData-list digest..." -- The information contained in this email and any attachments is confidential and may be legally privileged. If you have received this message in error, please notify the sender immediately and remove all copies of the message, including any attachments. Any views or opinions expressed in this email (unless otherwise stated) may not represent those of Hutt Valley DHB. Thank you. ** Disclaimer added by HVDHB **

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Outbreak analysis with Epidata Analysis diary
by epidata-list＠lists.umanitoba.ca 04 Jun '08

04 Jun '08

I use Epidata to help with the analysis of outbreaks of communicable disease. Up until now I have used Epidata to design the questionnaires and enter the data and Epi info to analyse the data, but for the last outbreak I used Epidata Analysis to do some of the analysis (to produce the attack rate table). This was much better than using epi info. I told Jens I might try using Epidata analysis for all the outbreak analysis in the future and he suggested I write some short notes about what I do, and post them to the list as the basis for a future field guide. We now have a brand new outbreak to analyse so I will do this and hope you will contribute with comments and suggestions if you do similar tasks or are interested. Thanks Christine Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 >>> <epidata-list-request(a)lists.umanitoba.ca> 26/05/2008 5:01 a.m. >>> Send EpiData-list mailing list submissions to epidata-list(a)lists.umanitoba.ca To subscribe or unsubscribe via the World Wide Web, visit http://lists.umanitoba.ca/mailman/listinfo/epidata-list or, via email, send a message with subject or body 'help' to epidata-list-request(a)lists.umanitoba.ca You can reach the person managing the list at epidata-list-owner(a)lists.umanitoba.ca When replying, please edit your Subject line so it is more specific than "Re: Contents of EpiData-list digest..." -- The information contained in this email and any attachments is confidential and may be legally privileged. If you have received this message in error, please notify the sender immediately and remove all copies of the message, including any attachments. Any views or opinions expressed in this email (unless otherwise stated) may not represent those of Hutt Valley DHB. Thank you. ** Disclaimer added by HVDHB **

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