Werner CEUSTERS Center of Excellence in Bioinformatics and Life Sciences

1. AMIA 2006 Panel:The Future of HL7Referent Tracking through HL7?Washington, DC, USA. November 14, 2006 Werner CEUSTERS Center of Excellence in Bioinformatics and Life Sciences University at Buffalo, NY, USA http://www.org.buffalo.edu/RTU

2. America’s future www.sfpix.com/health_saturdays/Heal_sat1.html

3. Evolution of Obesity in the US Morbidity and Mortality Weekly Report. September 15, 2006 / Vol. 55 / No. 36.

4. Worldwide HL7-membership United States www.justmadethisup.ru

5. Puzzle There seems to be a striking correlation between the increase in obesity incidence and HL7 activity.

6. Before solving that puzzle: My short personal history 1977 1959 - ... 2004 1989 2002 1992 1998

7. Since April 2006 Center of Excellence in Bioinformatics & Life Sciences Buffalo, NY

8. Buffalo ???? • Are you out of your mind ???

9. Well, … • I might be crazy … but I’m not stupid.

10. A B Correlation versus Causality X

11. HL7 Obesity causes My hypothesis about HL7 and Obesity

12. Argument 1: Advice from the Surgeon General • ‘The Nation must take an informed, sensitive approach to communicate with and educate the American people about health issues related to overweight and obesity.’ • ‘ACTION: The Nation must take action to assist Americans in balancing healthful eating with regular physical activity.’ physical activity http://www.surgeongeneral.gov/topics/obesity/calltoaction/fact_vision.htm

13. Argument 2: HL7 says … • ‘The truth about the real world is constructed through a combination (and arbitration) of such attributed statements only, and there is no class in the RIM whose objects represent "objective state of affairs" or "real processes” independent from attributed statements. As such, there is no distinction between an activity and its documentation.’

14. Therefore: Americans think that watching sports is as good as doing sports …

15. ... or reading about sports

16. What is the problem ? • ‘A message to mapmakers: highways are not painted red, rivers don't have county lines running down the middle, and you can't see contour lines on a mountain.’ William Kent, Data and Reality. First published by North Holland in 1978. Republished in 1998 by 1stBooks.

17. What HL7 lacks: a realist view of the world • The world exists ‘as it is’ prior to a cognitive agent’s perception thereof; • Cognitive agents build up through observations cognitive representations of the world; • To make these representations publicly accessible in some enduring fashion, these agents create representational artifacts that are fixed in some medium. Smith B, Kusnierczyk W, Schober D, Ceusters W. Towards a Reference Terminology for Ontology Research and Development in the Biomedical Domain. Proceedings of KR-MED 2006, November 8, 2006, Baltimore MD, USA

18. We should not be in the business of “concept representation” (Despite the fact there is an IMIA WG on this) But beware ! • These concretizations are NOT supposed to be the representations of these cognitive representations;

19. But beware ! • These concretizations are NOT supposed to be the representations of these cognitive representations; • They are representations of the corresponding parts of reality • They are like the images taken by means of a high quality camera;

20. They are not(or should not be) like the paintings of Salvador Dali Non-canonical (although nice looking) anatomy

21. The sad consequences … • Too much focus on ‘concepts’, information models, data models, … • Hence the many mistakes in concept-based terminologies; • Also many ambiguities in electronic patient records in which such terminologies are used.

22. A widespread misconception • ‘A variety of clinical terminology standards exist in the health care system, giving meaning to raw data and allowing for semantic interoperability. Systemized Nomenclature of Medicine (SNOMED) clinical terms are one example of a clinical reference terminology that provides for semantic interoperability.’ Pharmacotherapy. 2005;25(8):1116-1125.

23. The same type of location code used in relation to three different events might or might not refer to the same location. PtID Date ObsCode Narrative Three references of hypertension for the same patient denote three times the same disease. 5572 5572 5572 5572 2309 5572 298 5572 298 5572 47804 03/04/1993 12/07/1990 01/04/1997 04/07/1990 22/08/1993 01/04/1997 21/03/1992 12/07/1990 04/07/1990 22/08/1993 17/05/1993 26442006 2909872 9001224 26442006 9001224 79001 9001224 81134009 58298795 79001 26442006 Essential hypertension Accident in public building (supermarket) closed fracture of shaft of femur closed fracture of shaft of femur Accident in public building (supermarket) Closed fracture of radial head Other lesion on other specified region Essential hypertension closed fracture of shaft of femur Accident in public building (supermarket) Fracture, closed, spiral 5572 04/07/1990 79001 Essential hypertension 0939 24/12/1991 255174002 benign polyp of biliary tract If the same fracture code is used for the same patient on different dates, then these codes might or might not refer to the same fracture. 2309 21/03/1992 26442006 closed fracture of shaft of femur If two different fracture codes are used in relation to observations made on the same day for the same patient, they might refer to the same fracture If two different tumor codes are used in relation to observations made on different dates for the same patient, they may still refer to the same tumor. The same fracture code used in relation to two different patients can not refer to the same fracure. 0939 20/12/1998 255087006 malignant polyp of biliary tract Using codes does not prevent ambiguities as to what is described: how many disorders are listed?

24. Consequences • Very difficult to: • Count the number of (numerically) different diseases • Bad statistics on incidence, prevalence, ... • Bad basis for health cost containment • Relate (numerically the same or different) causal factors to disorders: • Dangerous public places (specific work floors, swimming pools), • dogs with rabies, • HIV contaminated blood from donors, • food from unhygienic source, ... • Hampers prevention • ...

25. Proposed Solution: Referent TrackingNow! That should clear up a few things around here ! • Purpose: • explicitreference to the concrete individual entities relevant to the accurate description of each patient’s condition, therapies, outcomes, ... Ceusters W, Smith B. Strategies for Referent Tracking in Electronic Health Records. J Biomed Inform. 2006 Jun;39(3):362-78.

26. 78 235 5678 321 322 666 427 Numbers instead of words • Method: • Introduce an Instance Unique Identifier(IUI) for each relevant particular (individual) entity

27. instance-of at t1 inst-of at t2 #1 #10 person instance-ofat t1 inst-of at t2 #2 #20 liver instance-of at t1 inst-of at t2 #3 #30 tumor instance-of at t1 inst-of at t2 #4 #40 treating clinic #5 #5 instance-of at t1 inst-of at t2 device #6 #6 The principle of Referent Tracking ‘John Doe’s liver tumor was treated with RPCI’s irradiation device’ ‘John Doe’s ‘John Smith’s liver liver tumor tumor was treated was treated with with RPCI’s RPCI’s irradiation device’ irradiation device’

28. EHR – Ontology “collaboration”

29. PtID Date ObsCode Narrative IUI-001 5572 5572 5572 5572 5572 47804 298 5572 2309 5572 298 22/08/1993 12/07/1990 12/07/1990 04/07/1990 04/07/1990 01/04/1997 17/05/1993 22/08/1993 03/04/1993 21/03/1992 01/04/1997 26442006 26442006 79001 9001224 9001224 79001 81134009 58298795 26442006 2909872 9001224 Accident in public building (supermarket) Other lesion on other specified region closed fracture of shaft of femur Accident in public building (supermarket) closed fracture of shaft of femur Essential hypertension Essential hypertension closed fracture of shaft of femur Fracture, closed, spiral Closed fracture of radial head Accident in public building (supermarket) IUI-001 IUI-001 IUI-007 5572 04/07/1990 79001 IUI-005 Essential hypertension 0939 24/12/1991 255174002 IUI-004 benign polyp of biliary tract 2309 21/03/1992 26442006 IUI-002 closed fracture of shaft of femur IUI-007 IUI-006 IUI-005 IUI-003 IUI-007 IUI-012 IUI-005 0939 20/12/1998 255087006 IUI-004 malignant polyp of biliary tract Advantage: better reality representation 7 distinct disorders

30. Does HL7 support this ?

31. At first sight: yes • Definition of Entity: • A physical thing, group of physical things or an organization capable of participating in Acts, while in a role. • Entity.id:: SET<II> (0..*) • Definition: A unique identifier for the Entity.

32. On closer inspection: no ! (just one example) • Discussion: • An entity is a physical object that has, had or will have existence. • Rationale (under determinerCode): • An Entity may at times represent information … This does not need to be a problem if for each entity it is specified whether it is a ‘first order’ thing in reality or an information object (‘second order’ entities are also real!)

33. So what is uniquely identified and how ? • The double confusion in HL7-RIM • X = information about X • X = observation of X • But clearly, the following entities are all distinct: • The pimple on my nose; • The observing of the pimple on my nose by that man; • That man asserting the existence of the pimple on my nose; • The information-object in the record which refers to the pimple on my nose; • …

34. Some claim: all these distinctions are in HL7 • ‘In HL7, we assert that Peter has a UML symbol with an object instance identifier assigned to "his disease" that includes an instance identifier assigned to his "type of disease".’ • But then: ‘Once consensus builds around the subject of concern, the patient can be said to "have" a specific disease. It can be said that "over time" the UML symbol instance identifier for the "concern" becomes the UML symbol instance identifier for the "disease.”’

35. Who is then sick: the clinician or the patient ? • ‘In HL7, we assert that Peter has a UML symbol with an object instance identifier assigned to "his disease" that includes an instance identifier assigned to his "type of disease".’ • But then: ‘Once consensus builds around the subject of concern, the patient can be said to "have" a specific disease. It can be said that "over time" the UML symbol instance identifier for the "concern" becomes the UML symbol instance identifier for the "disease.”’

36. There is hope … • My question: What kind of identifiers is the RIM using and what kind of identifiers go in HL7 messages. And moreover, what kind of identifiers are used in what place in object-oriented paradigms, UML-objects, etc. There is a big confusion here !

37. The answer • We agree very strongly in this area. I have been suggesting for many years that these proxy identifiers not be used as "object instance identifiers." Fortunately, more HL7 V3 people are beginning to agree and the ii datatype will soon allow us to differentiate between proxy instance identifiers and the truly arbitrary object instance identifiers known as UUID, GUID, or other similar constructs.

38. But at least until then … HL7-RIM is a Picasso interpretation of a Dali painting