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HL7 Interview Questions


1) A message is sent by sending application. When new MSH segment is constructed in response to original message by responding application what are the rules used to create initial message? i. In particular MSH-7 date/time of message and MSH-10 message control ID refers to the response message; they are not echoes of the fields in the initial message ii. MSH -5 receiving application, MSH-6 receiving facility, MSH-11 processing id contains codes that are copied from MSH-3 sending application, MSH-4 sending facility and MSH-11 processing ID in the initial message
2) What components are ignored while receiving HL7 messages and converting their contents to data values? Ignore segments, fields, components,sub-components and extra repetitions of field that are present but were not expected
3) What happens while receiving HL7 messages and converting their contents to data values?
a) Ignore segments, fields, components, sub-components and extra repetitions of field that are present but were not expected
b) Treat fields and components that are expected but were not included in a segment as not present
c) Treat segments that were expected but are not present as consisting entirely of fields that are not present
4) What is the name of the delimiter that is defined in the second field of the MSH segment?
Encoding characters
5) In original mode, which acknowledgement code is returned by the receiver if the originating message passes original syntactic validation but then is not processed successfully?
AE the Application Error code is returned
6) In original mode , which acknowledgement code is returned by the receiver if the originating message has an invalid value for message type, version ID , or processing control ID?
AR the Application Reject
7) In original mode which acknowledgement code is returned by the receiver if the originating message is processed successfully?
Application Accept AA
8) The four characters of MSH-2 contain the following four delimiters component separator, repetition separator, sub-component separator, escape character always in what order?
Component separator, repetition separator, sub-component separator, escape character
9) What does a message profile contain?
A message profile contains the definition of the transmitted data
10) In the field definition calls for a field to be broken into components what rules are used?
Following rules are used:
a. If more than one component is include they are separated by the component separator
b. Components that are present but null are represented by the characters “”
c. Components that are not present at the end of a field need not be represented by component separator
11) What is the encoding character in the following message segment given below
MSH|^~&|MegaReg|UABHospC|ImgOrdMgr|UABImgCtr|20010529090131-0500||ADT^A01|01052901|P|2.3.5 ?
The second segment in a message segment MSH-2 is the encoding character `^~&`
12) Give details on HL7 technical correction rules :-
Set of HL7 technical correction rules determine the technical corrections that can be applied between versions of HL7. IT gets done on a case-by-case basis.
Technical correction is possible in one or more of the following scenarios
1) Spelling corrections
2) Errors from external table imports like transcription errors
3) Examples with mistakes in prior versions of HL7
4) Problem (or) issues with descriptions
5) If there is an inconsistency between segment attribute table and field narrative it needs correction
6) Problem with section reference
13) What is HL7 RIM?
HL7 RIM is the abbreviation of Reference Information Model (RIM). HL7 version 3 is the latest version of HL7. Information on latest RIM from HL7 is documented in its normative editions latest being 2012
14) What happens when we delete the anchoring segment of the segment group?
All information in repeating segment group is deleted
15) What is a HL7 abstract message definition?
HL7 Control chapter deals with the set of generic rules that do apply to all messages. These rules are not confined to specific messages as such. These rules form basics of message construction, the type of data to be sent with each of them, the inter-relationship among messages. As these rules are pure application layer rules the level 7 rules this is also called abstract message definition
They form basics of constructing messages that applications particularly in a healthcare setup do make use of to interact with each other
16) Which segment allows for greater descriptions of erraneous conditions?
ERR segment
17) What is the purpose of FTS ?
FTS the file trailer segment defines the end of a file
18) Can we associate the trigger event with more than once with message type?
Yes, we can do that. A message type can always be associated with more than one trigger event
19) What are the many different parts of a message?
a) element
b) datatype
c) field
d) component
20) What is a trigger event?
Trigger event is a real world event that triggers the messages between systems in healthcare. HL7 is a standard. All others form part of message
21) The ORU message type is used to transmit information related to patients. What is transmitted using ORU message type?
Observation results
22) What are the responsibilities of HL7 standard in a software implementation?
HL7 takes care of data security, interface engine
23) What messages (or) message constituents can be changed?
Field datatype, data type component, descriptive text name of messages are the message constituent that can be changed
24) Which are the components of HD datatype?
Universal ID type, Universal ID, Namespace ID
25) Is Name of coding system component of HD datatype?
Nope
26) What can’t be changed as per HL7 compatibility rules?
segment group name
27) What can be changed as per HL7 compatibility rules?
Messages, message constituents
28) Which are basic type of messages defined in scheduling transaction set?
Request transaction, query transaction, unsolicited transaction
29) What is a trigger event?
An event in the real world of healthcare which creates the need for data to flow among systems
30) What is covered in HL7 message definitions?
a) adding messages
b) adding message constituents
c) changing messages
d) changing message constituents
31) In MSH what does the field MSH-6 represent?
Receiving facility
32) Which of the following fields from MSH segment have unique identifier used to relate the message response to the initial message?
MSH-10 message control ID
33) In MSH segment what does the field MSH-11 represent?
Processing ID
34) With what is a message type associated?
A message type in HL7 is associated with more than one trigger event
35) What are the capabilities expected to be provided by communication environment while integration using HL7?
Error free transmission, character conversion, message length
36) What are the modes of acknowledgement in HL7?
a. Application ACK
b. Accept ACK
37) What is the meaning of segments R,B,O,C?
Here is the meaning of many different segments :
R- required
B – left for the sake of backward compatibility with previous version of HL7
O – Optional
C- conditional
38) How many segments can a HL7 message contain. What is maximum limit?
120 is the maximum number of segments that a HL7 message can have
39) Which segment in HL7 contains the message control ID to be used by receiving system in message acknowledge segment MSA?
MSH-10 is the field that contains the message control ID. This field can be number or any other identifier. This is used to uniquely identify the message. It is used by receiving system to be used with MSA
40) Which segment defines number of batches contained in a file ?
FTS-1 is the file batch count segment. It is the field that contains details on number of batches contained in a file
41) When square brackets appear around the name of a segment [](or around a group of segment names) what does it mean?
It means that segment or group is optional
42) Given the following abstract message definition take the following example of an HL7 message of type ORM in response to the ADT message and check if it conforms to the AMS ?
Nope. Message control id is the different as that for the ADT or ACK message examples
43) You have been asked to choose between dedicated proprietory interface vs HL7. What advantages/disadvantages can you think of?
Dedicated proprietary interface scope becomes easy whereas HL7 scope definition is not easy. However in long run it is the best solution. Dedicated proprietory interface can be targeted to environment in which it operates. Dedicated proprietory interface can be optimized in its operating environment. HL7 interface has a broad scope and require more effort to define and constrain, but upon clearly defining scope it becomes easy to implement, maintain and extend
44) In response to a specific query which messages are not sent from an user or an application?
Unsolicited messages are not sent in response to a query from an user or application
45) What is the scope of HL7?
HL7 is a standard and its scope starts with specification of messages between application systems, determining communication environment including protocols like TCP/IP and triggering events. Specification of messages between application systems. Communication environment. Triggering events
46) In MSH segment what does the field MSA-4 represent?
Expected sequence number
47) In MSH segment what does the field MSH-3 represent?
Sending application
48) What is the use of MSH-25 segment?
Receiving network address
49) Which segment allows for unambiguous identification of a patient using one or more identifiers?
PID the Patient Information segment
50) Which field in message segment points to the location of message definition in the standard?
The MSH-9 segment is used for this purpose
51) In OSI model in which level of OSI does HL7 operate?
The seventh layer Application layer. HL7 operates on 7th layer the application layer
52) Give name of a standard that defines a series of predefined logical formats of packaging healthcare data in the form of messages to be transmitted among computer application systems :-
HL7 standard from hl7.org is designed to help application systems talk to each other. Starting with healthcare it has started gaining popularity among financial systems as well
53) What is purpose of A01 event?
A01 is basically used to trigger events related to patient admission. Some if its usage includes :
a) The pharmacy system that a patient has been admitted
b) The nursing system that the patient has been admitted
c) The finance system of the start of billing period
54) Which segment is mandatory in HL7 message?
The mandatory segment happens to be MSH
55) Give some optional segments in a HL7 message :-
ZAA,NTE, DSC
56) What does FTS signify?
FTS signifies the end of field
57) How do you know if a message is encoded using a different character set in a localized environment e.g French, German?
Choose answer:
The character set to be used can be specified in the MSH segment MSH-18
58) In enhanced mode which acknowledgement code is returned by the receiver if the originating message passes original syntactic validation but then cannot be accepted for same reason say for example the value of sequence number is invalid?
The code returned is CE the commit error
59) Which one among these escape sequences represents start highlighting?
Make use of the escape sequence H
60) An EKG waveform could be encoded in which of the following HL7 datatypes?
Using ED – Encapsulated Data
61) What is the specified maximum field length for a field of datatype IS?
20
62) In the segment attribute tables what information is provided in the column labeled DT?
The basic building block used to construct or restrict the contents of a data filed
63) In the segment attribute tables what information is provided in the columns labeled RP/#?
This represents whether the field may repeat
64) In ERR segment what does the field ERR-3 represent?
HL7 Error code
65) What does field ERR-11 represent in ERR segment?
Override reason code
66) Which datatype allows for the transmission of a name plus an identifier, identifier type, internationalization information, and the timestamp of some action and has 24 components?
PPN the performing person timestamp
67) Encoding Characters field is a part of which segment?
It is part of segment MSH
68) Patient arrivals at an ER is an example of which event?
This is an unsolicited event
69) Give details on some HL7 events :-
a. swap patients
b. unsolicited transmission of an observation message
c. delete person information
d. query sent for deferred response
70) Is application acknowledgement a HL7 event?
Nope
71) When transfer of information is initiated by the application that does not deal with the triggering event wha tis it called?
Query/response mode
72) Choose the escape sequence that represents escape character?
The escape character is E
73) HL7 operates at which OSI layer?
It operates at the Application level. HL7 is the application layer protocol and operates at seventh layer in HL7
74) What does BTS and FTS represent?
Batch trailer segment is BTS and FTS is field trailer segment
75) In MSH segment what does the field MSH-14 represent?
It represents Continuation Pointer
76) In ERR segment what does the field ERR-10 represent?
It represents Override type
77) In ERR segment what does the field ERR-6 represent?
Application Error parameter
78) In BH segment what does the field BSH-4 represent?
It represents Batch sending facility
79) What is meaning of ERR-1 in error segment ERR?
It represents Error code and location
80) What are the advantages/disadvantages of either using a dedicated , propreitory interface and an interface using HL7?
a) A dedicated, propreitory interface can be targeted and optimized to the environment in which it operates
b) HL7 interfaces are broader in scope and require more effort to define and constrain , but when well-defined are easier to implement, maintain, extend
81) Which escape sequence represents hexadecimal data?
This is represented by the escape sequence Xddd…
82) Scheduling transaction set is defined using what basic type of messages?
Scheduling transaction set is defined using request, query and unsolicited transaction messages.Request transaction, query transaction, unsolicited transaction
83) Which messages are not sent in response to a specific query from user or an application?
Unsolicited updates are not sent in response to a specific query from an user or an application
84) When the transfer of information is initiated by application system that deals with the triggering event, what is the transaction termed as?
Unsolicited update
85) In ERR segment what does the field ERR-4 represent?
Severity
86) Which datatype accommodates short data of 200 characters or less and contains printable characters except for the delimiter characters?
ST the string data type
87) How would you encode a price of $xUSA in HL7 message?
|x^USD|
88) Which is the most commonly used money datatype in HL7?
Using MO
89) Which escape sequence that represents subcomponent separator?
It is using escape sequence T
90) What datatype accommodates a code value, code text and the name of the coding system in which the value is defined?
CE
91) What segment in HL7 is used to represent date/time that the sending system created the message ?
MSH-7 is the field that contains details on date/time at which the sending system created the message. The timezone specified in here if any will be the default timezone
92) Which numeric datatype is used for transmitting test or observation results ,and permits multiple vectors to be delimited by the repetition separator?
The numeric datatype is NA
93) hat datatype is used for transmitting coded values in a single component from HL7 defined tables?
Using ID
94) Which numeric datatype is used for expressing qualified clinical results and ranges for example : |^300^-^400| which would indicate a value in the range of 300 to 400?
It can be represented using datatype NM
95) Which datatype is used to transmit patient identifier and its scope?
CX the extended composite ID with check digit
96) What are the parts of a message?
a) element
b) component
c) field
97) What is a trigger event in HL7?
Trigger event is a real world event that triggers the messages between systems in healthcare
98) Is it possible to plug and play with HL7?
a) No as there is lack of a common data model
b) No as it deals with message specifications only
c) No as there exists a lack of process conformity with vendors. Due to this conformance has to be separately defined as per site negotiations. Also there is lack of negotiations within vendor
99) What is an array in HL7?
Objects grouped together and have a notable relationship among each other are called as arrays
100) Which datatype is used in HL7 for the transmission of basic geographic address data ?
Make use of datatype XAD