Pathology requirements TIMED MEASUREMENTS
Bhupinder The protocol describes the methods of measurement - each measure can only have one protocol - so this means that the measurement would be entered twice - quite appropriate because it is unlikely that a different method will lead to exactly the same result. Cheers, Sam -Original Message- From: owner-openehr-technical at openehr.org [mailto:owner-openehr-technical at openehr.org]On Behalf Of Bhupinder Singh Sent: Thursday, 23 October 2003 1:12 PM To: Sam Heard; Openehr-Technical Subject: Re: Pathology requirements TIMED MEASUREMENTS Further to what you have stated there will also be events such as sample is single time is same and the test is same but method of reporting and or conducting test is different. Blood Sugar is one example sample is taken and tested on the bedside and sent to a lab also. These events and results need to be accommodated. Bhupinder - Original Message - From: Sam Heard sam.heard at bigpond.com To: Openehr-Technical openehr-technical at openehr.org Sent: Wednesday, October 22, 2003 4:02 PM Subject: Pathology requirements TIMED MEASUREMENTS TIMED MEASUREMENTS The timed nature of specimens is dealt with in the history and event model of the RM and available in the archetype editor. This deals with timed measurements and interval measurements. The idea of a 21 day progesterone is covered in state information relating to the time since the last menstrual period - BUT there is still the idea of an untimed sequence of events where the order is critical. There are also sequenced events when it comes to looking for stool microscopy, occult blood - but these are reported separately and really are administrative rather than of the nature I will describe here. The best examples of this seem to occur in sampling - three samples of CSF - the first, second and third - or shavings for histology looking for depth of tumour. There are more, such as respiratory function tests with particular challenges - and timing is not an issue. These occur one after the other but the sequence is the only thing that is important - not the time - and time would probably be made up. The question is, how do we deal with this. I think we have two choices: 1. We recognise this is a sampling issue and there should be a label on each sample which is transfered to the report - we have sample 1, 2 and 3 with three separate microscopies and cultures in a single composition. This would get around the confusion of trying to deal with this as a timing issue - it would work for any sampling including location. We do not want to compare these CSF samples in queries as equals but we would have some sort of label associated. So, the sample label and order might be part of this - in the request and then in the result. I guess this goes on at the moment. 2. We have a sequence idea in the event model, by using the offset but having 'sequence' as the unit rather than time. This would mean that people did not have to enter spurious times in the data and name the event as Sample 1, which could be misleading. Comments? Cheers, Sam Dr Sam Heard Ocean Informatics, openEHR Co-Chair, EHR-SIG, HL7 Chair EHR IT-14-9-2, Standards Australia Hon. Senior Research Fellow, UCL, London 105 Rapid Creek Rd Rapid Creek NT 0810 Ph: +61 417 838 808 sam.heard at bigpond.com www.openEHR.org www.HL7.org __ - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
FW: Re: Pathology requirements TEXTURAL RESULTS TO QUANTITIES
-Original Message- From: Sam Heard [mailto:sam.he...@bigpond.com] Sent: Friday, 24 October 2003 11:00 AM To: Tim Churches Subject: RE: Re: Pathology requirements TEXTURAL RESULTS TO QUANTITIES Tim As we seek to achieve automatic processing of some of the data in the EHR there will be clear efficiencies in changing some conventions. For instance, RBC/HPF = 0 is very easy to understand. They are not usually 'seen' anyway any more so why pretend. What I was getting at is when a numeric response is there - but wrong - and a textural entry replaces the quantity - as in 'haemolysed'. I am proposing that the archetype node to do this is not the same as the quantity - so it would replace it. It would then not come back in queries looking for K+ levels. Tom and I have thought about ranges as fuzzy quantities e.g. 100 or 0.5 - these are possible in all analytes in practice but rarely met. Thanks, Sam -Original Message- From: owner-openehr-technical at openehr.org [mailto:owner-openehr-technical at openehr.org]On Behalf Of Tim Churches Sent: Thursday, 23 October 2003 4:55 PM To: Tim Churches Cc: Sam Heard; Openehr-Technical Subject: Re: Re: Pathology requirements TEXTURAL RESULTS TO QUANTITIES Tim Churches tchur at optushome.com.au wrote: Sam Heard sam.heard at bigpond.com wrote: TEXTURAL RESULTS TO QUANTITIES ?TEXTUAL? This raises the general issue of how mixed categorical/ordinal/scalar quantities are handled eg (made up example) haematuria: Trace-x RBC/ml - Gross haematuria. Sorry, brain-fade. I meant x RBC/HPF (per high power field) or similar. This is an example of a sampled result i.e. a random sample of portions of a specimen are examined and a mean is reported. The mean is quantitative, but is just a point estimate of the central tendency of an underlying probability density function. Thus it may have a std dev or confidence intervals associated with it. Also, in this circumstance zero doesn't really mean zero and is generally not reported as such: if no RBC were seen in any HPF, then it will be reported as No RBC seen, not as mean RBC/HPF = 0. Generalising this, scalars which parameterise a probability distribution are different from scalars which are precise quantities - or are they? Hmmm. Tim C Conceivably some use might be made of the numbers, as opposed to the ordinal categorical extrema? Tim C - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements UNITS
Bhupinder
This is an interesting idea...but it raises issues as you have to have
normal ranges for each of these. I do not see why the results could not be
duplicated in multiple units is required - at present we do not have the
ability to add multiple values to a single element apart from as reference
ranges.
What do others think? I think Labs will probably push back on this one.
Sam
-Original Message-
From: owner-openehr-technical at openehr.org
[mailto:owner-openehr-technical at openehr.org]On Behalf Of Bhupinder Singh
Sent: Thursday, 23 October 2003 1:30 PM
To: Sam Heard; Openehr-Technical
Subject: Re: Pathology requirements UNITS
Can we not work on a UNITS module where a test can be attached to a number
of units where the conversion is not available. A clinician does
not want to
have to relearn the unit for the convenience of the application.
Bhupinder
- Original Message -
From: Sam Heard sam.heard at bigpond.com
To: Openehr-Technical openehr-technical at openehr.org
Sent: Wednesday, October 22, 2003 4:02 PM
Subject: Pathology requirements UNITS
UNITS
There are a lot of units out there - it has been our idea to build a
constraint model on units based on the property being measured. A good
example is frequency can be '/{time unit}' (e.g. /min, /hr, /s) or 'Hz'.
It
is hoped that we can translate from one to the other as much as possible
on
this basis.
It has come to my attention just how many units are out there and that
some
units are not translatable to another unit even when the property is the
same without further information. The best known example is gm percent -
which is the same as gm/100ml or gm/dl. This is a concentration
but it is
not possible to know the amount of substance (moles) without knowing the
molecular weight of the substance. This means we will have to have units
available in a property that are not translatable. We could
separate these
to MASS CONCENTRATION and CONCENTRATION as some have done - but I think
clinicians will want to choose from as small as list as possible.
We need some work done in this area and there are a number of documents
available to get this as tidy as we can.
Cheers, Sam
Dr Sam Heard
Ocean Informatics, openEHR
Co-Chair, EHR-SIG, HL7
Chair EHR IT-14-9-2, Standards Australia
Hon. Senior Research Fellow, UCL, London
105 Rapid Creek Rd
Rapid Creek NT 0810
Ph: +61 417 838 808
sam.heard at bigpond.com
www.openEHR.org
www.HL7.org
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Pathology requirements CONTRIBUTION - 2 versions at once
Bhipinder Thank you. I think we have all of these issues covered. Sam -Original Message- From: owner-openehr-technical at openehr.org [mailto:owner-openehr-technical at openehr.org]On Behalf Of Bhupinder Singh Sent: Thursday, 23 October 2003 1:23 PM To: Sam Heard; Openehr-Technical Subject: Re: Pathology requirements CONTRIBUTION - 2 versions at once You have factored the details relating to reporting. A major issue is the transmission and reading of the result by the clinician. Ther is to be time event to be recorded as to when the clinician who has direct control of the patient has read it. A legal issue that will come up at times is that the report shall be claimed to have been sent and the consultant clinician shall claim not to have received it and thus not having read it. A timed event for both these activities need to be available. Further there is a need for alerting the clinicians once the report is ready. There is a need to have the ability to generate an Interim report and then a final report. It is the interim report that shall have to be avilable to few and the detailed subsequently. Both these have to be a part of the EPR to substantiate the clinican actions in case of a abnormal event when the action of the clinician results in a abnormal event in the patients recovery. Even when the sample is haemolysed a track of the sample needs to be kept in the EPR of the patient. Bhupinder - Original Message - From: Sam Heard sam.heard at bigpond.com To: Openehr-Technical openehr-technical at openehr.org Sent: Wednesday, October 22, 2003 4:02 PM Subject: Pathology requirements CONTRIBUTION - 2 versions at once CONTRIBUTION - 2 versions at once There is a particular problem with results that are deemed to be incorrect as the specimen is damaged - haemolysed blood samples being the most common (See textural results to quantities thread). If the machine read data is to be preserved in openEHR then this would need to be over written with the correct result and both compositions saved at the same time - otherwise some other agent might base some process on the interim situation where the first composition is saved even for a microsecond. We think this relates to machine processed data - but keeping medical student entries might be dealt with in some environments in the same manner. ACCESS CONTROL to interim reports There will be times when the access to an interim report needs to be controlled - such as an abnormal result from a lab that has not been signed off by the final arbitor...but it may need to be available to a particular team. Our access control models need to deal with this. Cheers, Sam Dr Sam Heard Ocean Informatics, openEHR Co-Chair, EHR-SIG, HL7 Chair EHR IT-14-9-2, Standards Australia Hon. Senior Research Fellow, UCL, London 105 Rapid Creek Rd Rapid Creek NT 0810 Ph: +61 417 838 808 sam.heard at bigpond.com www.openEHR.org www.HL7.org __ - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements TEXTURAL RESULTS TO QUANTITIES
I think the fact that some results are a mean calculated by a human is a red-herring. In fact nearly all numerical analyte values from automated machines are a mean of a number of estimates - part of the internal quality control is that the standard deviation of these estimates is acceptable - this is just hidden under the hood. Some systems certainly record a value of 0, instead of, or in a addition to, zero RBC per HPF. How many HPF's are examined and acceptable values for the SD when done manually are all part of the analysis technique used and not generally stored in the patients paper record, let alone EHR. Regards Vince Vincent McCauley MB BS, Ph.D - Original Message - From: Tim Churches tc...@optushome.com.au To: Tim Churches tchur at optushome.com.au Cc: Sam Heard sam.heard at bigpond.com; Openehr-Technical openehr-technical at openehr.org Sent: Thursday, October 23, 2003 17:25 Subject: Re: Re: Pathology requirements TEXTURAL RESULTS TO QUANTITIES Tim Churches tchur at optushome.com.au wrote: Sam Heard sam.heard at bigpond.com wrote: TEXTURAL RESULTS TO QUANTITIES ?TEXTUAL? This raises the general issue of how mixed categorical/ordinal/scalar quantities are handled eg (made up example) haematuria: Trace-x RBC/ml - Gross haematuria. Sorry, brain-fade. I meant x RBC/HPF (per high power field) or similar. This is an example of a sampled result i.e. a random sample of portions of a specimen are examined and a mean is reported. The mean is quantitative, but is just a point estimate of the central tendency of an underlying probability density function. Thus it may have a std dev or confidence intervals associated with it. Also, in this circumstance zero doesn't really mean zero and is generally not reported as such: if no RBC were seen in any HPF, then it will be reported as No RBC seen, not as mean RBC/HPF = 0. Generalising this, scalars which parameterise a probability distribution are different from scalars which are precise quantities - or are they? Hmmm. Tim C Conceivably some use might be made of the numbers, as opposed to the ordinal categorical extrema? Tim C - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements UNITS
Sam et al,
At least in the Australian context there are regulatory requirements
to report in Standard units only. So reporting the same
result in multiple different units is not possible.
What the standard units are, will vary across different realms
Regards
Vince
Dr Vincent McCauley
- Original Message -
From: Sam Heard sam.he...@bigpond.com
To: Bhupinder Singh bobdog at sancharnet.in; Openehr-Technical
openehr-technical at openehr.org
Sent: Friday, October 24, 2003 11:35
Subject: RE: Pathology requirements UNITS
Bhupinder
This is an interesting idea...but it raises issues as you have to have
normal ranges for each of these. I do not see why the results could not be
duplicated in multiple units is required - at present we do not have the
ability to add multiple values to a single element apart from as reference
ranges.
What do others think? I think Labs will probably push back on this one.
Sam
-Original Message-
From: owner-openehr-technical at openehr.org
[mailto:owner-openehr-technical at openehr.org]On Behalf Of Bhupinder Singh
Sent: Thursday, 23 October 2003 1:30 PM
To: Sam Heard; Openehr-Technical
Subject: Re: Pathology requirements UNITS
Can we not work on a UNITS module where a test can be attached to a
number
of units where the conversion is not available. A clinician does
not want to
have to relearn the unit for the convenience of the application.
Bhupinder
- Original Message -
From: Sam Heard sam.heard at bigpond.com
To: Openehr-Technical openehr-technical at openehr.org
Sent: Wednesday, October 22, 2003 4:02 PM
Subject: Pathology requirements UNITS
UNITS
There are a lot of units out there - it has been our idea to build a
constraint model on units based on the property being measured. A good
example is frequency can be '/{time unit}' (e.g. /min, /hr, /s) or 'Hz
'.
It
is hoped that we can translate from one to the other as much as
possible
on
this basis.
It has come to my attention just how many units are out there and that
some
units are not translatable to another unit even when the property is
the
same without further information. The best known example is gm
percent -
which is the same as gm/100ml or gm/dl. This is a concentration
but it is
not possible to know the amount of substance (moles) without knowing
the
molecular weight of the substance. This means we will have to have
units
available in a property that are not translatable. We could
separate these
to MASS CONCENTRATION and CONCENTRATION as some have done - but I
think
clinicians will want to choose from as small as list as possible.
We need some work done in this area and there are a number of
documents
available to get this as tidy as we can.
Cheers, Sam
Dr Sam Heard
Ocean Informatics, openEHR
Co-Chair, EHR-SIG, HL7
Chair EHR IT-14-9-2, Standards Australia
Hon. Senior Research Fellow, UCL, London
105 Rapid Creek Rd
Rapid Creek NT 0810
Ph: +61 417 838 808
sam.heard at bigpond.com
www.openEHR.org
www.HL7.org
__
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If you have any questions about using this list,
please send a message to d.lloyd at openehr.org
-
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Pathology requirements TIMED MEASUREMENTS
Bhupinder Singh said: Further to what you have stated there will also be events such as sample is single time is same and the test is same but method of reporting and or conducting test is different. Blood Sugar is one example sample is taken and tested on the bedside and sent to a lab also. These events and results need to be accommodated. If I understand correctly, we are talking about the same sample, but being tested twice? These are separate tests, and could take place a quite different times (e.g. hours apart); they are done by different methods, and probably different providers/people. They will become available in the EHR at different times, so the only thing in common really is the source of the sample - and this should be reported in the test data. - thomas beale - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements TEXTURAL RESULTS TO QUANTITIES
Tim Churches wrote: Sam Heard sam.heard at bigpond.com wrote: TEXTURAL RESULTS TO QUANTITIES ?TEXTUAL? This raises the general issue of how mixed categorical/ordinal/scalar quantities are handled eg (made up example) haematuria: Trace-x RBC/ml - Gross haematuria. Conceivably some use might be made of the numbers, as opposed to the ordinal categorical extrema? The current DV_ORDINAL data type consists of an integer value representing the ordinal position in a range of values, and a symbol, which is the symbol given to that position. Ordinals are treated as being comparable ( operator is defined) but not quantified (the magnitude is unknown). We currently think that the correct way to express the symbol is as a term in a vocabulary (maybe subsetted). This means that each set of symbols comes from its own micro-vocabulary, and even if the same symbols (like trace, +, ++) are used for unrelated things, they cannot get mixed up in comparisons. Examles: pain: Value Symbol 1+ 2++ 3+++ reflex Value Symbol 1+ 2++ 3+++ haemolysed blood in urinalysis 1 ?neg? 2 ?trace? 3 ?small? 4 ?moderate? 5 ?large? OR - haemolysed blood in urinalysis (unit=cells/ml) 1 ?neg? 2 ?trace (10) 3 ?small (25) 4 ?moderate (80) 5 ?large (200) I am not sure if we need more sophistication to deal with this. The main problem I see is the lack of vocabularies, and/or non-standardisation of them. I guess LOINC has the kinds of values we want, but how to specify the correct subsets? - thomas beale - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements UNITS
Bhupinder Singh bobdog at sancharnet.in wrote:
Can we not work on a UNITS module where a test can be attached to a number
of units where the conversion is not available. A clinician does not want to
have to relearn the unit for the convenience of the application.
I wonder if units should be considered part of a localsation profile?
Currently you can specify units in an archetype in two ways:
a) as the actual units you want to allow, e.g. units matches {mm[Hg]}, units
matches {km, mi}
b) property matches {pressure}, property matches {length}
A nice alternative that Sam has thought of is:
c) property matches {FORCE/LENGTH^2} -- same as pressure
property matches {LENGTH/TIME}
We are currentl working on including this in ADL.
- thomas
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Pathology requirements CONTRIBUTION - 2 versions at once
Bhupinder Singh bobdog at sancharnet.in wrote: You have factored the details relating to reporting. A major issue is the transmission and reading of the result by the clinician. Ther is to be time event to be recorded as to when the clinician who has direct control of the patient has read it. A legal issue that will come up at times is that the report shall be claimed to have been sent and the consultant clinician shall claim not to have received it and thus not having read it. A timed event for both these activities need to be available. Further there is a need for alerting the clinicians once the report is ready. Agree with all this. However, the EHR on its own cannot force people to read things. So applications need to create alerts as necessary, and then what happens next is dependent on policies. For example, one strategy is: * if an item is added to the EHR, say a prelim test result at time t1, and a clinician in the group having access to the EHR makes a decision and commences an action (e.g. new investigation which is more expensive) for this patient at time t5, then a reasonable rule of operation is that the clinician must have made this decision with knowledge of the result recorded at t1, since in a shared EHR to which he/she has access, there is no reason why not; if they have not done so, they might be in breach of their duty. The arguments against this working might be that if the EHR is bady organised, there might be no easy way to find the relevant item(s) whcih might influence the decision at time t5. So at least problem-threading and/or episode classification is needed... Another strategy would be: * the clinician receives an alert of some kind (e..g email) and is required to go into the EHR and change the test result in a field which means seen and accepted by treating clinician; dated xx/xx/xx hh:mm:ss. This acceptance is now in the EHR, and it can be seen that it must have been part of the basis of the next actions by the clinician. However, later actions by others might still occur without knowledge of this accepted test result - unless the first strategy is followed. So - I think that the first strategy is at least needed, but it does not mean that there does not need to be countersigning etc within the clinical workflow somewhere the question is - how much of this finds its way into the EHR? - thomas beale There is a need to have the ability to generate an Interim report and then a final report. It is the interim report that shall have to be avilable to few and the detailed subsequently. Both these have to be a part of the EPR to substantiate the clinican actions in case of a abnormal event when the action of the clinician results in a abnormal event in the patients recovery. Even when the sample is haemolysed a track of the sample needs to be kept in the EPR of the patient. Bhupinder - Original Message - From: Sam Heard sam.heard at bigpond.com To: Openehr-Technical openehr-technical at openehr.org Sent: Wednesday, October 22, 2003 4:02 PM Subject: Pathology requirements CONTRIBUTION - 2 versions at once CONTRIBUTION - 2 versions at once There is a particular problem with results that are deemed to be incorrect as the specimen is damaged - haemolysed blood samples being the most common (See textural results to quantities thread). If the machine read data is to be preserved in openEHR then this would need to be over written with the correct result and both compositions saved at the same time - otherwise some other agent might base some process on the interim situation where the first composition is saved even for a microsecond. We think this relates to machine processed data - but keeping medical student entries might be dealt with in some environments in the same manner. ACCESS CONTROL to interim reports There will be times when the access to an interim report needs to be controlled - such as an abnormal result from a lab that has not been signed off by the final arbitor...but it may need to be available to a particular team. Our access control models need to deal with this. Cheers, Sam Dr Sam Heard Ocean Informatics, openEHR Co-Chair, EHR-SIG, HL7 Chair EHR IT-14-9-2, Standards Australia Hon. Senior Research Fellow, UCL, London 105 Rapid Creek Rd Rapid Creek NT 0810 Ph: +61 417 838 808 sam.heard at bigpond.com www.openEHR.org www.HL7.org __ - If you have any questions about using this list, please send a message to d.lloyd at openehr.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org -- Deep Thought: http://www.deepthought.com.au openEHR: http://www.openEHR.org - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
Pathology requirements TIMED MEASUREMENTS
Bhupinder Singh bobdog at sancharnet.in wrote: Dear Sam, What you say is correct. In clinical practice it is also possible that the same sample is sent to two labs for the same test and the protocol followed by both the labs is same so is the est method and the unit of reporting. The sample date and time is the same. These two results have to be viewed and stored. Thus there should be a method to store and retrieve values where the date and time of sample and the test type and method and the UOM is the same needs to be available. Eg Blood Sugar reporting unit and test method are the same so is the date and time of the sample. Bhupinder this is an inteersting scenario actually, since even if there are two perfectly legitimate test results (let's say submitted to the EHR a day after each other) they don't really represent distinct results - they are the same result (presumably) submitted at same or different times. Wen doing statistical or other queries we have to be careful - if we draw the values on a graph for example of bsl over last five days, there might be two values at the one timepoint (where the timepoints are the times of taking samples, not doing the test - i.e. the biologically significant point in time). One way to look at thist situation is to say that all test results where there is just a single result are just a special case of a statistical testing situation in which at any point in body time, a sample might be tested any number of times (and more than one sample might be made as well) - giving a constellation of results. Where there are multiple results for the one biological timepoint, we could consider it as a statistical strengthening of the confidence in the result. Probably what applications processing the results should do is consider N results at the same biological timepoint to be the same as one, whoe value is the mean of the N, and whose confidence is some higher value than that attributed to single value samples. - thomas beale - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
