- EpiData-list - University of Manitoba Mailing Lists

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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Re: EpiData-list Digest, Vol 55, Issue 19 Missing values is not NA
by epidata-list＠lists.umanitoba.ca 29 May '08

29 May '08

Dear friend Ziad, NA is common expression to identify missing values. If you are working with R or S-Plus then NA is NA. That means that all functions or commands that you want to specify NA, the expression is also NA. However, in Stata or Epidata entry the NAs are epecified by dots (.) and sometimes by empty quotes (" ") depending if the variable of interest is formated as numeric or text. So, my guess is that your check command will work fine if do like this... AFTER ENTRY IF v64=. THEN LET V65=9 & V66=9 & goto V67 ENDIF END Best regards, Pedro Emmanuel > Today's Topics: > > 1. If..then (epidata-list(a)lists.umanitoba.ca) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 28 May 2008 08:47:34 -0700 > From: epidata-list(a)lists.umanitoba.ca > Subject: [EpiData-list] If..then > To: epidata-list(a)lists.umanitoba.ca > Message-ID: > <897a5cf60805280847u3b99c66ak6f49e3855b879141(a)mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Hi, > might be easy question, i am trying to write condition under check > file to write value of 9 in 2 places if one cell equal to NA (code > below), it does not work (and no error message), any tips? > > AFTER ENTRY > IF v64=NA THEN > LET V65=9 & V66=9 & goto V67 > ENDIF > > > Thank you in advance > best regards > ziad > > > ------------------------------ > > ________________________________________ > EpiData-list(a)lists.umanitoba.ca > http://lists.umanitoba.ca/mailman/listinfo/epidata-list > > > End of EpiData-list Digest, Vol 55, Issue 19 > ******************************************** >

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re: If..then
by epidata-list＠lists.umanitoba.ca 28 May '08

28 May '08

Just split in three lines: after entry IF v64=NA THEN LET V65=9 V66=9 goto V67 ENDIF regards Jens Lauritsen EpiData Association

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Epidata Analysis and diagnostic test accuracy analysis
by epidata-list＠lists.umanitoba.ca 27 May '08

27 May '08

Hi all, I did look at epidata website but for any unknown reasean I could not find the pdf manual of EpiData analysis. I use a lot the epidata entry but neve tryed before the analysis. I would like to know if any of you could tell me if EpiData analysis has resources to analyse diagnostic test accuracy such as sensitivity, specificity (and theses estimates in different prevalences), estimate the area under the ROC curve, draw ROC curves, compare ROC curves form different tests? I also did try to download/install the software and look for theses abilaties, but here at the institute where I work none of the users are coputers administrator (security reasons) and install "non standart softwares" is just not that simple! Thanks a lot in advance! -- Abraço forte e que a força esteja com você, Pedro Emmanuel

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Re: [EpiData-list] Program simulated data in EpiData (Analysis)
by epidata-list＠lists.umanitoba.ca 25 May '08

25 May '08

Greetings SK, [This may be a repeat -- first posting didn't seem to get through] I like to use a little program by Christian Maas to generate data, Random file generator from: http://www.chmaas.handshake.de/delphi/freeware/freeware.htm The command line version can be run from a BAT file containing a statement such as: RndFileC.exe /R=50000 /Z=YYYY/MM/DD /N=4 /F=1,@ /C=15 /F=1,, /B /C=1 /S=14 /B /C=1 /S=14 /F=1,@ /Y=1945,2003 data.txt For example, this generates 50,000 records with the given date format and range, plus other fields. Then import into EpiData. I prefer to set up the EpiData files, enter a few records, and then export them to a CSV file; then make sure you use the same format to generate the random records to import back into EpiData. I have use Maas's program to generate 8,000,000 records (but not this number for EpiData; this was data to analyze using gawk in GNU/Linux). The sort program is real nice, too. Hope this helps, Pete Geddes geddes(a)ix.netcom.com ----- Original Message --------------- Subject: [EpiData-list] Program simulated data in EpiData (Analysis) From: epidata-list(a)lists.umanitoba.ca Date: Sun, 25 May 2008 09:38:58 -0400 To: epidata-list(a)lists.umanitoba.ca > >Dear All > >I was wondering if EpiData Analysis could do simulations: here is what I am contemplating doing; I have created a database of admissions/discharges from a hospital using a standardized register and using EpiData as the software for data entry and ana;ysis. I wish to populate the fields (15 in total, of various types: boolean, categorical with k values, numeric, and date fields) I have created with say N=5,000 observations. The reason I wish to do this is to show the stakeholders (in this case Hospital Managers and Unit Heads) that one could use simple yet effective data entry and analysis software (like EpiData) to monitor and evaluate hospital-based programs. I wanted them to see EpiData in action with the simulated data--starting with EpiData Entry and then with Analysis. > > > >Can simulation be done in Analysis? or should I prepare the dataset with Stata or SAS and then import in EpiData--I am not sure how to do this, but I will search around to see how to get it done? > > > >Thanks, > >SK >

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How to: Simulation with EpiData Analysis
by epidata-list＠lists.umanitoba.ca 25 May '08

25 May '08

Simulation for entry is not that easy. But some tests have been done with "recording software". The results of this could be uploaded if there is an interest. Simulation for analysis is rather simple. The simplest way is: close * generate x empty observations, e.g. 1000: generate 1000 * then generate the variables: e,g, integer sex: gen i sex = 1 if recnumber > 499 then sex = 0 .... continue with other variables. * look also in the help file for: random functions. The extended way is to use the user specified commands. For explanation of this see: The documentation page or the direct download link at: http://www.epidata.dk/php/downloadc.php?file=cmd_command_epidata_analysis.p… Kind regards Jens Lauritsen EpiData Association

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Program simulated data in EpiData (Analysis)
by epidata-list＠lists.umanitoba.ca 25 May '08

25 May '08

Dear All I was wondering if EpiData Analysis could do simulations: here is what I am contemplating doing; I have created a database of admissions/discharges from a hospital using a standardized register and using EpiData as the software for data entry and ana;ysis. I wish to populate the fields (15 in total, of various types: boolean, categorical with k values, numeric, and date fields) I have created with say N=5,000 observations. The reason I wish to do this is to show the stakeholders (in this case Hospital Managers and Unit Heads) that one could use simple yet effective data entry and analysis software (like EpiData) to monitor and evaluate hospital-based programs. I wanted them to see EpiData in action with the simulated data--starting with EpiData Entry and then with Analysis. Can simulation be done in Analysis? or should I prepare the dataset with Stata or SAS and then import in EpiData--I am not sure how to do this, but I will search around to see how to get it done? Thanks, SK

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Default values in boolean fields
by epidata-list＠lists.umanitoba.ca 22 May '08

22 May '08

The simplest solution for default values is to use the chk command "Defaultvalue" Further explanation is shown in the help file. eg qes: v1 my boolean variable <y> v2 ....... etc chk v1 defaultvalue 0 end regards Jens Lauritsen

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improvised checkboxes
by epidata-list＠lists.umanitoba.ca 21 May '08

21 May '08

I understand that epiData does not have checkboxes as such. Therefore the boolean fieldtype is suggested. In order to save time when entering data for certain variables, I would like to have epiData automatically write N, if nothing is entered. Otherwise all dummy variables are created as missing, unless I type "0" or "N" in each field. Is there a way to do this automatically? I already tried MISSINGVALUE N or MISSINGVALUE 0 and AFTER RECORD IF saaadr = . THEN saaadr=0 ENDIF END but unfortunately with no result. Thanks in advance for any suggestion. Marius _________________________________________________________________ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx

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