This LOINC-Valueset  https://hl7.eu/fhir/laboratory/0.1.0-ballot/ValueSet-lab-studyType-eu-lab.html    with only 7 values is used for category of DiagnReports and of Observation results:
18717-9    Blood bank studies (set)
18719-5    Chemistry studies (set)
18722-9    Fertility studies (set)
18723-7    Hematology studies (set)
18725-2    Microbiology studies (set)
18728-6    Toxicology studies (set)
26436-6    Laboratory studies (set)

We recognize some kinds of inconsistencies:

• This valueset is very limited. WHY don't you use this IHE XD-LAB - Value Set: https://art-decor.ihe-europe.net/art-decor/decor-valuesets-XDLAB?id=1.3.6.1.4.1.19376.1.3.11.1&effectiveDate=2008-08-08T00:00:00&language=en-US  ( ##content copied below)

• A Study types valueset with a limitation of such a few values should not have a "required" binding, but instead a more open binding

• And terminologies need to be clarified: what is the difference between "Laboratory speciality" and "Study type" → the meaning of the terms "Laboratory speciality" or "Study type" has to be considered, when using and assigning the valuesets "Laboratory speciality" or "Study type". 

• There should be EUROPEAN terminology standard with a clear distinction between category of DiagnReport and category of an Observation.

Kind regards from Martina Sender (mio42 GmbH, Germany)

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18717-9 BLOOD BANK STUDIES
18718-7 CELL MARKER STUDIES
18719-5 CHEMISTRY STUDIES
18720-3 COAGULATION STUDIES
18721-1 THERAPEUTIC DRUG MONITORING STUDIES
18722-9 FERTILITY STUDIES
18723-7 HEMATOLOGY STUDIES
18724-5 HLA STUDIES
18725-2 MICROBIOLOGY STUDIES
18727-8 SEROLOGY STUDIES
18728-6 TOXICOLOGY STUDIES
18729-4 URINALYSIS STUDIES
18767-4 BLOOD GAS STUDIES
18768-2 CELL COUNTS+DIFFERENTIAL STUDIES
18769-0 MICROBIAL SUSCEPTIBILITY TESTS
26435-8 MOLECULAR PATHOLOGY STUDIES  
26436-6 LABORATORY STUDIES  
26437-4 CHEMISTRY CHALLENGE STUDIES
26438-2 CYTOLOGY STUDIES