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NLM Classification 2017: Worldwide source of medical library classification

Scope of Revision for the 2017 Summer Edition


NLM Classification Updated in Two Phases

Starting with 2017, the NLM Classification moved from an annual spring update to twice-yearly updates.

The 2017 winter version, published January 26, 2017, encompassed changes to the NLM Classification resulting from new and changed 2017 Medical Subject Headings (MeSH) terms as well as additional minor updates to the index and schedule.

The 2017 summer version, published August 31, 2017, encompasses the systematic review of particular schedules and other miscellaneous updates.

Scope of Revision of the 2017 Summer Edition

Summary Statistics for the 2017 Summer Edition

  • 57 class numbers added
  • 2 schedule outline headers added
  • 207 class number captions or notes modified; indentation levels changed; group labels modified
  • 19 schedule outline headers modified
  • 11 class numbers canceled
  • 5 schedule headers deleted
  • 75 index main headings added
  • 526 index entries modified
  • 99 index headings deleted

Systematic Reviews for the 2017 Summer Edition

The major focus of the 2017 summer version was the systematic review of the following schedules: WI (Digestive System), WN (Radiology. Diagnostic Imaging), and a partial review of the WM schedule: WM 140-308 (Mental Disorders) due to major restructuring of Mental Disorders tree (F3) based on revisions to the Diagnostic and Statistical Manual of Mental Disorders (DSM).

Highlights from the WI (Digestive System) Review

  • The gastrointestinal tract moved from the WI 100 area (digestive system) to its own new number: WI 190
  • Several new class numbers created for disease terms, e.g., Esophageal Diseases, formerly classed at WI 250 Esophagus, now classed in the new number WI 255 Esophageal diseases (General)
  • The large intestine moved from WI 400 Intestines (General) to its own new number: WI 518.
  • For specificity and consistency, the specific region names added in front of existing generic disease and surgery class captions. For example, WI 320 changed from Neoplasms to Stomach neoplasms; WI 480 changed from Surgery (General) to Intestinal surgery.
  • Distinction made between Abdomen (now classed in new number WE 757) and Abdominal Cavity (classed at WI 900).
  • New number, WI 980, created for general works on surgery of the digestive system or gastrointestinal tract.

Highlights from the WM 140-308 (Mental Disorders) Review

With 2016 MeSH, major changes were made to the Mental Disorders F3 tree based on revisions to the Diagnostic and Statistical Manual of Mental Disorders (DSM). The corresponding areas of the NLM Classification were updated.

  • Behavioral symptoms for which there are no classification numbers for related disorders, now classed in WM 140 with general mental disorders rather than WM 165. WM 165 now limited to works on self-injurious and dangerous behaviors.
  • New number, WM 168, created for Neurodevelopmental Disorders in adults.
  • New number, WM 169, created for Attention Deficit and Disruptive Behavior Disorders in adults.
  • Neurotic Disorders deleted as a header for WM 170-197. Class numbers WM 171 through WM 184 were outdented to the far left level equal to Neurotic Disorders.
  • Several specific personality disorders added to the existing A-Z structure at WM 190.5.
  • WM 190.5.I6 (Impulse control disorders. Gambling. Fire setting behavior) canceled and redirected to new number, WM 192.
  • The header for WM 200-220 changed from Psychotic Disorders to Schizophrenia Spectrum and Other Psychotic Disorders. Class numbers WM 202 through WM 220 were outdented to the far left level equal to Psychotic Disorders.
  • The WM 270-290 Substances-Related Disorders area broadened to include Behaviors:
    • New number, WM 273, created for Alcohol Drinking.
    • Marijuana use added to caption at WM 276 Marijuana abuse. Use of medical marijuana is classified in WB 925. Legalization of marijuana classified in QV 732-733.
    • Tobacco use added to caption at WM 290 Tobacco use disorder. References to HV and QV under Tobacco Use deleted in the index.
    • Smoking dependence redirected from WM 290 to new number, WM 295, created for Smoking in general. References to HV and QV under Smoking were deleted in the index.

Highlights from the WN (Radiology. Diagnostic Imaging) Review

  • WN 250 vs. QZ 269 Radiotherapy clarified:
    • WN 250- Includes works focusing on general aspects of radiotherapy.
    • QZ 269 - Includes works focusing on treatment of neoplasms
  • Changes to classification of radioactive elements:
    • Medical uses of radioactive elements classed in WN 440-450.
    • Adverse effects of radioactive elements classed in WN 610-615.
    • Works on general physics and chemistry of radioactive elements are classed in LC’s QC or QD schedule.
    • Class numbers, WN 300 General works on Radium, WN 340, Therapeutic use of radium, and WN 415 Biological aspects of nuclear medicine and atomic energy, canceled. The corresponding headers were deleted.
  • WN 600, Radiological health, is restricted to general effects of ionizing radiation on humans.
    Animals and plant life excluded.
  • Several changes made to WN 610-630 area:
    • WN 610, Radiation injuries, now limited to humans. Radiation effects on plants classed in LC’s QK schedule. Radiation injuries from radiography and radiotherapy procedures classified here rather than with the procedure.
    • WN 615, Radioactive pollution and pollutants (General), now includes general works on radioactive hazard releases.
    • WN 620, formerly Injurious effects on man and animals, now limited to Experimental radiation injuries, which per MeSH is for vertebrate animals only/
    • WN 630, Injurious effects on plant life (related to human ecology) canceled. Radiation effects on plants classed in LC’s QK schedule.

Other 2017 Summer Edition Changes

In addition to the systematic reviews of the WI, WM, and WN schedules, other additions and changes were made:

Table G Changes

The Table G notation for FA1 Great Britain updated to reflect the MeSH change from Great Britain to United Kingdom.

Form Number Policy Change

Use of the form numbers 5, 7, and 9 no longer restricted to works that cover the overall subject of the schedule.

Global Climate Change and Human Health

New number, WA 30.2, created for Climate Change. Climate Change, Global Warning, and Greenhouse Effects were redirected from WB 700 Medical geography to this new number. Table G added to WB 710 Diseases of geographic areas. WB 700 should be used for works with no geographic emphasis.

Classification of Medicinal Plants

Sixteen (16) new numbers for specific medicinal plants were added under the new A-Z structure under QV 766. Medicinal plants not fitting in any A-Z number will be classed in QV 766. Specific medicinal plants with geographic distribution are classed in QV 770. Non-medicinal aspects of plants are classed in the appropriate QK number.

Genetic Processes Changes

With 2017 MeSH, the term Genetic Processes was deleted. The NLM Classification was updated to reflect this change:

  • QU 475 Genetic processes was changed to Gene expression. Gene expression regulation
  • QU 477 Pathologic genetic processes was changed to Genetic variation and outdented
  • New numbers were created for:
    • QU 55.97 -- Transcription factors
    • QU 510 -- DNA damage. DNA repair
    • QU 515 -- DNA replication
    • QU 520 -- Molecular evolution. Genetic selection