IHTSDO Observables Project Group April 21, 2008 Evanston, Illinois Exploration of Possible Concept Models for Observable Entities Revised based on discussion IHTSDO Observables Project Group April 21, 2008 Evanston, Illinois

Examples of Observables Histologic type = ? (carcinoma, adenoca,…) Tumor site = ? (lung, brain, …) Ability to hear = ? (able, unable, …) Serum sodium level = ? (N, Abn, 129mg/dl) Pupil size = ?(N, large, small, 9mm, …) Total body water (amount) =?(x…) Response to sound Hearing examination No! This is a procedure

Agreement based on prior discussions: Measurement procedures are different from the observable that they measure More generally, observation procedures are different from the entities they observe

A draft model for observables Organize the observable entity hierarchy using attributes similar to the current measurement procedure attributes Use existing COMPONENT, PROPERTY, TIME ASPECT, and SCALE TYPE Change domain from Measurement procedures to Observables Expand and revise allowable value domains Replace HAS SPECIMEN with SYSTEM (perhaps keep HAS SPECIMEN as a role hierarchy sub-role of SYSTEM) Permit anatomical sites, body substances, as well as specimens Replace MEASUREMENT METHOD with TECHNIQUE (perhaps keep MEASUREMENT METHOD as a role hierarchy sub-role of TECHNIQUE) Create a new techniques value set Move to their own hierarchies, separate from observables: functions processes activities Allow functions, processes, activities also to be values of COMPONENT (in addition to substances, organisms, cell structures) Do not allow observables to be values of COMPONENT

SYSTEM / OBSERVABLE SITE DRAFT model of observables Observable entity COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Properties SYSTEM / OBSERVABLE SITE Specimens, Sites TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

SYSTEM / OBSERVABLE SITE Example (1): ability to hear (observable) Ability to hear COMPONENT To hear (function) PROPERTY Ability SYSTEM / OBSERVABLE SITE Specimens, Sites TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (2): blood hemoglobin concentration Blood Hb concentration COMPONENT Hemoglobin PROPERTY Concentration SYSTEM / OBSERVABLE SITE Blood TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (3): Right Pedal pulse (observable) R Pedal Pulse COMPONENT Systemic arterial pulse PROPERTY detectability SYSTEM / OBSERVABLE SITE Right dorsalis pedis artery TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE Palpation

Example (4): Ability to see red-green (observable) COMPONENT Red-green color vision (function) = to see red-green PROPERTY Ability SYSTEM / OBSERVABLE SITE Specimens, Sites TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (5): Knee-jerk deep tendon reflex briskness (observable) Knee-jerk reflex briskness COMPONENT Knee-jerk reflex PROPERTY briskness SYSTEM / OBSERVABLE SITE ? Patellar tendon ? Quadriceps muscle TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

SYSTEM / OBSERVABLE SITE Example (6): Head circumference (observable) (option 1) Head circumference COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Circumference SYSTEM / OBSERVABLE SITE Head TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (6): Head circumference (observable) (option 2) COMPONENT Circumference PROPERTY Distance (linear dimension) SYSTEM / OBSERVABLE SITE Head TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (6): Head circumference (observable) (option 3) COMPONENT Head PROPERTY Distance (linear dimension) SYSTEM / OBSERVABLE SITE Patient TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Alternative model Use “observable property” as the top level of a hierarchy characterized by properties (also known as qualities), which can have locations etc. PROPERTY, COMPONENT and SYSTEM rolled into a single value

independent continuant DRAFT alternative model of observables Observable entity PROPERTY properties INHERES IN independent continuant PROPERTY FUNCTION function PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (1): ability to hear (observable) PROPERTY ability (property) INHERES IN Subject’s auditory system PROPERTY FUNCTION To hear (function) PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (2): blood hemoglobin concentration Blood Hb concentration (observable) PROPERTY Concentration (property) INHERES IN Subject’s intravascular blood OF FUNCTION functions OF SUBSTANCE hemoglobin TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (3): Right Pedal pulse (observable) PROPERTY detectability INHERES IN Right dorsalis pedis artery PROPERTY FUNCTION Systemic arterial pulsation PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE palpation

Example (4): ability to see red-green (observable) PROPERTY ability (property) INHERES IN visual system PROPERTY FUNCTION To see red-green (function) PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

stretch reflex (deep tendon reflex) Example (5): Knee-jerk deep tendon reflex briskness (observable) Observable entity PROPERTY briskness INHERES IN Quadriceps muscle PROPERTY FUNCTION stretch reflex (deep tendon reflex) PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Example (6): Head circumference (observable) Observable entity PROPERTY circumference INHERES IN head PROPERTY FUNCTION function PROPERTY SUBSTANCE substances TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Values for PROPERTY Top levels of value hierarchy – determined by empirical analysis of values in the observables hierarchy Detail Dimension Feature Fluid property Force property Location Quantity Ratio Result Stage Temperature Time Velocity Wave property

dimension [2] (possible: size) observable entity property kind dimension [2] (possible: size) area [20] distance (synonym: linear dimension) breadth [20] circumference [27] depth [7] diameter [31] height [29] length [42] width [11]

Replace MEASUREMENT METHOD with more general TECHNIQUE Proposal: For observation and evaluation procedures, the METHOD (with values from the action hierarchy) represents the goal or objective of what is done: evaluation, testing, imaging, measurement, examination observation techniques define the observable, via TECHNIQUE (with values from a value set that includes lab techniques and other specific measurement and evaluation actions, such as inspection, palpation, percussion, auscultation) Techniques are the means by which the action is carried out, not the intended outcome. Techniques include specific measurement techniques such as Enzyme-linked immunosorbent assay (ELISA). Need to examine whether this works for procedures other than evaluations, i.e. can we make the distinction between METHOD (means) and TECHNIQUE for all procedures

Possible use of observables An observable can represent the object (in the linguistic sense) of a measurement or observation May serve as value for OBSERVATION OF attribute of a measurement or observation procedure An observable can take values to form a finding Serves as value for the INTERPRETS attribute of a clinical finding.

Options for Observation Procedures Link observation procedures to observables via a new attribute OBSERVATION OF Procedure : OBSERVATION OF = observable OR 2. Define observation procedures via a series of attributes (COMPONENT, PROPERTY, SYSTEM, TIMING, SCALE, TECHNIQUE) which also defined the observable that is observed. In this case, the connection from observation procedure to observable is inferable but has no populated attribute.

Modeling procedures using OBSERVATION OF For measurement procedures (observation procedure), the main attributes are METHOD = measurement – action OBSERVATION OF = (observable entity)

Option 1: with “OBSERVATION OF” Observation procedure METHOD observation G OBSERVATION OF Observable entity COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Properties SYSTEM / OBSERVABLE SITE Specimens, Sites G TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Option 2: no observable intermediary Observation procedure METHOD observation COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Properties SYSTEM / PROCEDURE SITE Specimens, Sites G TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Options for Observation Findings Link observation findings to observables via existing attribute (INTERPRETS) Finding : INTERPRETS = observable OR 2. Define observation findings via a series of attributes (COMPONENT, PROPERTY, SYSTEM, TIMING, SCALE, TECHNIQUE) which also define the observable that is observed. In this case, the connection from observation finding to observable is inferable but has no populated attribute.

SYSTEM / OBSERVABLE SITE Option 1: with “INTERPRETS” Clinical finding HAS INTERPRETATION value G INTERPRETS Observable entity COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Properties SYSTEM / OBSERVABLE SITE Specimens, Sites G TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Option 2: no observable intermediary Clinical finding HAS INTERPRETATION value COMPONENT Substances, functions, processes, activities, organisms, cell structures PROPERTY Properties SYSTEM / FINDING SITE Specimens, Sites G TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE techniques

Pedal pulse Pedal pulse palpable HAS INTERPRETATION palpable COMPONENT PROPERTY intensity SYSTEM / FINDING SITE Dorsalis pedis artery G TIME ASPECT Time aspects SCALE / UNITS Scale types, units TECHNIQUE palpation

Examples Right pedal pulse (observable) Right pedal pulse present (finding) Palpation of right pedal pulse (procedure)

Right pedal pulse present FINDING SITE HAS INTERPRETATION palpable G INTERPRETS Right pedal pulse (Observable entity) COMPONENT Systemic arterial pulse G PROPERTY palpability SYSTEM Right dorsalis pedis artery TECHNIQUE palpation

Right pedal pulse present FINDING SITE (SYSTEM) HAS INTERPRETATION palpable COMPONENT Systemic arterial pulse G PROPERTY palpability SYSTEM (FINDING SITE) Right dorsalis pedis artery TECHNIQUE (FINDING METHOD) palpation

Palpation of right pedal pulse Observable entity OBSERVATION OF G METHOD observation - action PROCEDURE SITE COMPONENT Systemic arterial pulse G PROPERTY palpability SYSTEM Right dorsalis pedis artery TECHNIQUE palpation

Palpation of right pedal pulse METHOD observation - action PROCEDURE SITE / SYSTEM COMPONENT Systemic arterial pulse G PROPERTY palpability SYSTEM / PROCEDURE SITE Right dorsalis pedis artery TECHNIQUE palpation

Right pedal pulse present FINDING SITE HAS INTERPRETATION palpable G INTERPRETS Palpation of right pedal pulse Observable entity OBSERVATION OF G METHOD observation - action PROCEDURE SITE COMPONENT Systemic arterial pulse G PROPERTY palpability SYSTEM Right dorsalis pedis artery TECHNIQUE palpation

Role composition Can be used to link findings to sites via observables INTERPRETS ο SYSTEM → FINDING SITE findingX: INTERPRETS = observableY AND observableY: SYSTEM [OBSERVABLE SITE] = siteZ IMPLIES findingX: FINDING SITE = siteZ Example: absent R pedal pulse (finding): INTERPRETS = R pedal pulse (observable) R pedal pulse (observable): SYSTEM = R dorsalis pedis artery (body structure) absent R pedal pulse (finding): FINDING SITE = R dorsalis pedis artery (body structure)

Role composition Can be used to link procedures to sites via observables OBSERVATION OF ο SYSTEM → PROCEDURE SITE DIRECT procedureX: OBSERVATION OF = observableY AND observableY: SYSTEM [OBSERVABLE SITE] = siteZ IMPLIES procedureX: PROCEDURE SITE DIRECT = siteZ Example: Measurement of head circumference: OBSERVATION OF = head circumference (observable) Head circumference (observable): SYSTEM = head structure (body structure) Measurement of head circumference: PROCEDURE SITE DIRECT = head structure (body structure)

Additional examples

Measurement of substance in system Lab test finding HAS INTERPRETATION value G INTERPRETS Measurement of substance in system observable OBSERVATION OF G METHOD measurement - action COMPONENT substance PROPERTY concentration SYSTEM / OBSERVABLE SITE system

Below lower limit of reference range Low serum sodium HAS INTERPRETATION Below lower limit of reference range G INTERPRETS Measurement of serum sodium concentration Serum sodium concentration OBSERVATION OF G METHOD measurement - action COMPONENT sodium PROPERTY concentration SYSTEM / OBSERVABLE SITE serum

of ability to see red-green Ability to see red-green (observable) Red-green color blind HAS INTERPRETATION unable G INTERPRETS Observation of ability to see red-green Ability to see red-green (observable) OBSERVATION OF G METHOD observation - action COMPONENT To see red-green (function) PROPERTY ability

Ability to hear (observable) Hearing impaired HAS INTERPRETATION impaired G INTERPRETS Observation of ability to hear Ability to hear (observable) OBSERVATION OF G METHOD observation - action COMPONENT To hear (function) PROPERTY ability

Lateralization of observations Four options for the concept on which to place LATERALITY=side FINDING-SITE body structure value Observable Observable-SYSTEM body structure value Observable-COMPONENT value Requires LATERALITY to apply to functions

able to hear on the right side HAS INTERPRETATION able INTERPRETS Ability to hear (observable) FINDING SITE Lateral auditory system (? Ear) LATERALITY right COMPONENT To hear (function) PROPERTY ability

able to hear on the right side HAS INTERPRETATION able G INTERPRETS Ability to hear COMPONENT To hear (function) PROPERTY ability LATERALITY Right

able to hear on the right side HAS INTERPRETATION able INTERPRETS Ability to hear COMPONENT To hear on a side (function) LATERALITY right PROPERTY ability

able to hear on the right side Has-interpretation able Interprets Ability to hear Component To hear (function) Property ability SYSTEM / OBSERVABLE SITE lateral auditory system laterality right

Impact on procedure models METHOD and TECHNIQUE need to be differentiated This may be possible by differentiating: Means Objective Need

MON* analysis Procedures can be described in terms of their Means: how they were done Objective/goal: what was the result intended Need: motivation for the procedure *Shortening of the MOAN Acronym credited to Angelo Rossi Mori

Modeling procedures Means: Objective/goal: Need: Currently modeled with METHOD: incision, excision, etc Objective/goal: Also currently modeled with METHOD Repair, fixation, imaging Need: Modeled with HAS FOCUS Dysfunction, pain, disease

Modeling observations Means: New: TECHNIQUE (an attribute of a procedure or an observable) Objective/goal: Modeled with METHOD, using goal-type actions such as testing, imaging, evaluation, measurement Need: Modeled with HAS FOCUS

Examples (1) Microscopic urinalysis (procedure) Determining the contents of a urine specimen by microscopy METHOD = inspection – action HAS OBSERVABLE = contents of urine determined by microscopy Contents of urine determined by microscopy (observable) TECHNIQUE = microscopy SYSTEM = urine specimen COMPONENT = multiple (cells, casts, crystals, microorganisms, …) PROPERTY = Presence or identity

Examples (2) Measurement of serum Borrelia antibody by ELISA (procedure) METHOD = measurement OBSERVATION OF = serum Borrelia antibody (observable) Borrelia antibody (observable) PROPERTY = concentration COMPONENT = Borrelia antibody (substance) SYSTEM = serum TECHNIQUE = Enzyme Linked Immunosorbent Assay

Models rejected

Observation procedure Clinical finding Interprets Observation procedure Component Observable entity Component Function

Red-green color blind (finding) Observation of ability to see red-green (procedure) Interprets Ability to see red-green (observable) Component Red-green color vision (function) Component