- EpiData-list - University of Manitoba Mailing Lists

RE: EpiData-list Digest, Vol 41, Issue 2
by epidata-list＠lists.umanitoba.ca 09 Mar '07

09 Mar '07

I agree with the approach of Annenmieke van Middelkoop about 'invalid' records after "Read". Bernard Branger, Nantes, France __________________________________________________________________________ I have several concerns about this approach. 1. Most important, records with 'invalid' dates are excluded from analysis (10 in this example). The fact that the 'invalid' dates are likely to be incorrect is no reason to not be able to analyse the records. 2. READing a large dataset with many dates can be a very slow process. 3. The output given by Analysis (as shown above) is not very useful. Neither record numbers nor variable names are identified. I would like to suggest: a. That dates are not checked at all during the READ process. The analyst can look for incorrect dates in Analysis, relevant to the content of the data. OR b. That the user can specify whether to check the dates or not on READing a dataset. OR c. That, if neither a. nor b. is an option, more detail about the 'invalid' dates (record number, variable name) is provided so that they can be edited. Annemieke van Middelkoop Pretoria, South Africa ------------------------------ ________________________________________ EpiData-list(a)lists.umanitoba.ca http://lists.umanitoba.ca/mailman/listinfo/epidata-list End of EpiData-list Digest, Vol 41, Issue 2 *******************************************

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READ statement
by epidata-list＠lists.umanitoba.ca 07 Mar '07

07 Mar '07

When READing a dataset in Analysis, the program checks all dates in the dataset for 'valid' dates. For example, on reading a dataset DATA.REC, the following message is displayed: . Read Loading data C:\TEST\DATA.REC, please wait.. invalid year 1000, month 1, day 17 Error field DLOPV record: 1401 invalid year 5001, month 6, day 18 invalid year 200, month 1, day 16 invalid year 199, month 8, day 8 invalid year 200, month 2, day 2 invalid year 2200, month 12, day 3 invalid year 202, month 12, day 10 invalid year 202, month 12, day 10 invalid year 200, month 12, day 4 invalid year 200, month 12, day 4 invalid year 202, month 12, day 19 invalid year 603, month 5, day 24 invalid year 603, month 6, day 24 invalid year 199, month 1, day 15 invalid year 203, month 8, day 23 invalid year 203, month 8, day 23 invalid year 993, month 1, day 1 invalid year 199, month 9, day 19 invalid year 802, month 1, day 17 invalid year 199, month 4, day 18 invalid year 996, month 7, day 17 invalid year 206, month 7, day 31 invalid year 200, month 5, day 11 Errors reading data File name : C:\TEST\DATA.REC Fields: 222 Total records: 10460 Valid records: 10450 Excluded records: 10 I have several concerns about this approach. 1. Most important, records with 'invalid' dates are excluded from analysis (10 in this example). The fact that the 'invalid' dates are likely to be incorrect is no reason to not be able to analyse the records. 2. READing a large dataset with many dates can be a very slow process. 3. The output given by Analysis (as shown above) is not very useful. Neither record numbers nor variable names are identified. I would like to suggest: a. That dates are not checked at all during the READ process. The analyst can look for incorrect dates in Analysis, relevant to the content of the data. OR b. That the user can specify whether to check the dates or not on READing a dataset. OR c. That, if neither a. nor b. is an option, more detail about the 'invalid' dates (record number, variable name) is provided so that they can be edited. Annemieke van Middelkoop Pretoria, South Africa

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Re: [EpiData-list] Entering time and date for outbreaks
by epidata-list＠lists.umanitoba.ca 28 Feb '07

28 Feb '07

Hi Charity Thanks very much for your formula. Its sounds really good. I had a go at putting it in a check file. Following through your example below 'Diatime' is my 'vtime2' and 'diadate' is my vdate2. I thought I would start off slowly by seeing if I coudl calculate Vhours2. I created a new field called Vhours2 in my rec file and then I put the following code into the check file. DIATIME AFTER ENTRY LET VHOURS2=INT(DIATIME)+(FRAC(DIATIME)/0.6)+(DIADATE*24) END END Epi accepted the code but nothing appears in the vhours2 field when I enter information in the diadate and diatime fields. Can you see what I am doing wrong? thanks Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 >>> <epidata-list(a)lists.umanitoba.ca> 26/02/2007 7:24 p.m. >>> Hello Chrsitine, I prefer to enter times as a decimal field, i.e. ##.##. I can then put checks in place to make sure the minutes are in correct time format e.g. IF Frac(vtime) > 0.59 THEN .... Based on this decimal 24 hour time format, I have a formula which you can use to calculate the difference in hours between two time and date combinations. Assume that your first time and date are vtime1 and vdate1, and your second time and date are vtime2 and vdate2: First calculate the number of hours (since 31st December 1899) for both time and date combinations (store them as vhours1 and vhours2) using the following formulae: vhours2=Int(vtime2) + (Frac(vtime2)/0.6) + (vdate2*24) vhours1=Int(vtime1) + (Frac(vtime1)/0.6) + (vdate1*24) And then you can just calculate the time difference /incubation period into a different variable! timediff=vhours2-vhours1 You could also have done something similar and perhaps simpler using EpiData's Time2Num function which will convert a decimal time into a number between 0 and 1 representing a fraction of a day - I just prefer to work with hours. To explain the hours calculation formula for you (only need to read below if you care how the formula works): Int(vtime) takes the integer part of the time, and Frac(vtime) takes the fractional part of the time. These are separated so Frac(vtime) alone can be converted from minutes into fraction of an hour (e.g. from 0.30 to 0.50). The date integer (representing the number of days since 31 Dec 1899) is then multiplied by 24 to get the number of hours since 31 Dec 1899. This 1899 date is relevant only because it is how EpiData stores the date as an integer - we do not have to worry about this because we only care about the difference between the two dates. Hope this helps! Charity Charity Jenkins Data Processing Officer Centre for Behavioural Research in Cancer The Cancer Council Victoria http://www.cancervic.org.au/cbrc<https://webmail.accv.org.au/exchweb/bin/redir.asp?URL=http://www.cancervic.…> On 2/26/07, epidata-list(a)lists.umanitoba.ca <epidata-list(a)lists.umanitoba.ca> wrote: > > Hello everyone > > I am after advice about the best way to record time and date > information when collecting information about food poisoning outbreaks, > given epidata does not have a time/date field. We want this information > to estimate incubation periods, in order to get clues about the likely > illness. > > Incubation > Incubation = time from when someone is exposed to the time they become > unwell. > For example someone may eat a buffet meal at 7pm on 21 February and > become unwell at 1am on 22 February = incubation of 6 hours. > > Current method > At the moment we: > a) enter information in two fields. OnsetDay is recorded in a date > field, and onsettime in a numeric field (####) > b) list the two fields (using epi info) to view the information > c) calculate incubation manually. > > Is there a better/easier way to do this? Also what is the recommended > way for entering 24 clock time - should 7.30pm be 1930 or 19.30 > > thanks very much > > Christine > > > > Christine Roseveare > Analyst > Regional Public Health > 570 9194 > 027 495 9671 > > > > > -- > 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 ** > > _______________________________________________ > EpiData-list mailing list > EpiData-list(a)lists.umanitoba.ca > http://lists.umanitoba.ca/mailman/listinfo/epidata-list > -- 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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work-arounds for data entry on more than one computer
by epidata-list＠lists.umanitoba.ca 28 Feb '07

28 Feb '07

Epi-Data users: What strategies have you used to get around the limitation of only being able to input the data on one computer? We are thinking of splitting the file into two - with Type A respondents in one file/on one computer and Type B respondents in another file/on a different computer and then combining the resulting datasets in Stata. Will this work? Are there other/better strategies? Thanks, Kristine Hopkins khopkins(a)prc.utexas.edu

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Re: [EpiData-list] Entering time and date for outbreaks
by epidata-list＠lists.umanitoba.ca 27 Feb '07

27 Feb '07

Hi Charity I have tried adapting that check code to my file, just changing the field names as necessary, and it worked perfectly. How exciting to see my incubation times popping up effortlessly! Thanks very much for that. Christine Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 >>> <epidata-list(a)lists.umanitoba.ca> 27/02/2007 12:24 p.m. >>> Hi Christine, I think I forgot to mention that for vhours to be a field it needs to be fairly large as the number of hours since 1899 is a big number. Also it needs to have two decimal places. I used a nine digit number plus two decimals when I tried it. Once you know you have it working you could calculate the difference directly into the timediff field (which also needs two decimal places but does not need to be nearly as large) without having to store it in vhours1 and vhours2 first, to save having meaningless numbers lying about. Also, I didn't use the word "LET" - not sure if this makes any difference. And the number will not calculate until all the fields in the formula are filled, i.e. if you put the code in the time field but do not yet have anything in the date field, it will not work. I put the full calculation in all fields so that any time a field was updated the difference would update also. I will paste what I did below and hopefully it will clear anything else up I've forgotten to mention! Let me know how you go. Thanks, Charity Below is the text from the qes file I used to test my formulae. vtime1 ##.## vdate1 <dd/mm/yyyy> vhours1 #########.## vtime2 ##.## vdate2 <dd/mm/yyyy> vhours2 #########.## timediff ####.## And the code I used in my chk file (for the second time and date only, to save space): vtime2 MUSTENTER AFTER ENTRY IF (vtime2 < 0) OR (vtime2 > 23.59) OR (Frac(vtime2) > 0.59) THEN HELP "Enter a valid time" GOTO vtime2 ENDIF vhours2=Int(vtime2) + (Frac(vtime2)/0.6) + (vdate2*24) vhours1=Int(vtime1) + (Frac(vtime1)/0.6) + (vdate1*24) timediff=vhours2-vhours1 END END vdate2 MUSTENTER AFTER ENTRY vhours2=Int(vtime2) + (Frac(vtime2)/0.6) + (vdate2*24) vhours1=Int(vtime1) + (Frac(vtime1)/0.6) + (vdate1*24) timediff=vhours2-vhours1 END END vhours2 NOENTER END Charity Jenkins Data Processing Officer Centre for Behavioural Research in Cancer The Cancer Council Victoria http://www.cancervic.org.au/cbrc<https://webmail.accv.org.au/exchweb/bin/redir.asp?URL=http://www.cancervic.…> On 2/27/07, epidata-list(a)lists.umanitoba.ca <epidata-list(a)lists.umanitoba.ca > wrote: > > Hi Charity > > Thanks very much for your formula. Its sounds really good. I had a go > at putting it in a check file. Following through your example below > 'Diatime' is my 'vtime2' and 'diadate' is my vdate2. I thought I would > start off slowly by seeing if I coudl calculate Vhours2. I created a new > field called Vhours2 in my rec file and then I put the following code > into the check file. > > > DIATIME > AFTER ENTRY > LET VHOURS2=INT(DIATIME)+(FRAC(DIATIME)/0.6)+(DIADATE*24) > END > END > > Epi accepted the code but nothing appears in the vhours2 field when I > enter information in the diadate and diatime fields. Can you see what I > am doing wrong? > > > thanks > > Christine Roseveare > Analyst > Regional Public Health > 570 9194 > 027 495 9671 > > -- 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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date time difference and age calculation
by epidata-list＠lists.umanitoba.ca 26 Feb '07

26 Feb '07

In writing documentation, help file, how to's, faq solutions etc. the problem is not so much to give solutions, but how to write solutions in a way where users actually find them. For the age calculation if you look in EpiData Entry file under "time functions" you will see: ................... LET INT1=(ROUND(INT((TODAY-D1)/365.25)) Calculates the age of a person whose date of birth was entered in D1. Round is needed to convert the result of the calculation from a real number to a integer number. ................... and if you look in the help file for entry under "time functions" or "time about" or "Age on specific date" one example clearly shows how to do the calculations questioned on the list recently. The time example is also included with the installation of the Entry programme. I am not saying this to "point fingers" at the recent questioning on this list, but to underline that despite the amount of documentation, field notes, help files etc. it is my firm conviction that there is a definite need for a lively help line. For users following the Stata list or having used the very large volume of documentation and help facilities for Stata (www.stata.com) you will notice that also on that list questions shows up on issues actually explained but users not finding them. In other words: We can and should include obvious "often asked issues" in documentation, but even if we do, there will be someone not finding this information. Which is exactly why a large user base where someone find and take the time to answer these questions on the EpiData list is very important. Regards Jens Lauritsen EpiData Association

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Entering time and date for outbreaks
by epidata-list＠lists.umanitoba.ca 26 Feb '07

26 Feb '07

Hello everyone I am after advice about the best way to record time and date information when collecting information about food poisoning outbreaks, given epidata does not have a time/date field. We want this information to estimate incubation periods, in order to get clues about the likely illness. Incubation Incubation = time from when someone is exposed to the time they become unwell. For example someone may eat a buffet meal at 7pm on 21 February and become unwell at 1am on 22 February = incubation of 6 hours. Current method At the moment we: a) enter information in two fields. OnsetDay is recorded in a date field, and onsettime in a numeric field (####) b) list the two fields (using epi info) to view the information c) calculate incubation manually. Is there a better/easier way to do this? Also what is the recommended way for entering 24 clock time - should 7.30pm be 1930 or 19.30 thanks very much Christine Christine Roseveare Analyst Regional Public Health 570 9194 027 495 9671 -- 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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Current age calculation
by epidata-list＠lists.umanitoba.ca 25 Feb '07

25 Feb '07

Thank you Jamie for today mornings message. I was confused by the complex syntax of American date selection This solution was also obtained over the week end while working on a Fedora Linux machine on which Epidata entry and Analysis latest versions were installed.. Simple formulas, which produced wonders, are given below; define interval ### let interval=wdate - dbirth *calculate the interval in days using American dates. define interval ### let interval=(wdate dbirth)30.44 results in a error Data type mismatch define interval ###.# let interval=(wdate dbirth)/30.44 calculates the interval months using American dates. Epi Analysis accepts float type variables as suggested by Gillis Delmas. However round or integer prefix do not help. The output is produced in decimals and not rounded to the nearest figure. I wanted to obtain the current age hence did not include this formula in Epidata Entry as suggested by Pedro Emmanuel Brasil One request to Jens; Such examples should be included in the help file in the form of simple FAQs, which can save hours or even days of Epi Analysis Users (beginner and even experienced!!). Thank you friends for your timely help Much appreciated Dr. Shavinder Singh

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Age Calculation
by epidata-list＠lists.umanitoba.ca 24 Feb '07

24 Feb '07

Dear Friends, Thanks for your time and effort. I tried in so many many ways. Nothing is working. I am attching a sample file with following PGM. The error message obtained are shown in the next line beginning with "*" Kindly help. With regards, Dr. Shavinder Singh *Try.pgm cls close set echo=off set replace logfile=on read "d:\work\amdate.rec" define wdateu <DD/MM/YYYY> LET wdateu=wdate define dbirthU <DD/MM/YYYY> LET dbirthU=dbirth logopen "TRY.PGM OUTPUT FILE" /CLOSE define interval ### let interval=date("wdateu","dmy")- date("dbirthu","dmy") list Interval *Error message - (NO RESPONSE) define interval2 ### let interval2=Integer(date("wdate" - "dbirth")) list Interval2 *Error message Access violation at address 006C91D6 in module 'EPIDATASTAT.EXE'. Read of address FFFFFFFF define interval3 ### let interval3=Integer(date("wdate") - date("dbirth")) list Interval3 *Error message - (NO RESPONSE) define interval4 ### let interval4=Integer(round(date("wdate","mdy")- date("dbirth","mdy"))) list Interval4 *Error message -(NO RESPONSE) close

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<IDNUM> in statusbar!!
by epidata-list＠lists.umanitoba.ca 24 Feb '07

24 Feb '07

Hi Jamie, thanks for helping me out with the <IDNUM> problem! You also answered my other question about how to show the <IDNUM> in the statusbar. Bye, Ben.

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