MedlinePlus Connect: Planning for Clinical Coding System Changes

RESULTS

GEMS ANALYSIS

GEMs METHOD 1: RANDOM SAMPLING

Only 16% of the total forward mapping GEMs and 14% of the sample of 376 provide identical matches, while 84% of the total forward mapping GEMs and 86% of the sample of 376 provide approximate matches. The Associate Fellow analyzed the random sample to see if the identical matches require any review and how many of these approximate matches are useful for MedlinePlus Connect. A goal was to determine if approximate matches are useful for MedlinePlus Connect and the extent to which manual review is necessary. The comparison with LHC data will allow us to determine which requires the least amount of manual review and the most exact matches.

Fifty-two mappings out of the initial sample of 376 were identical matches. Out of these 52, 25 had ICD-10-CM descriptions that were similar to but not exactly identical in wording to the ICD-9-CM descriptions. Thirteen of these 25 have descriptions that while slightly different are almost exactly the same in meaning. The remaining 14 had different descriptions but similar meanings. All the identical matches were analyzed and all but 2 provided appropriate associations for MedlinePlus Connect to use within an EHR. Therefore, 96% of all identical matches provide appropriate Health Topics.

While the sample of 324 approximate mappings included 262 (81%) correct mappings or mappings where the health topic originally assigned to the ICD-9-CM code also worked for the ICD-10-CM code, 62 approximate mappings (19% of approximate mappings) provided incorrect or problematic mappings. Several broad categories of differences were observed (see Table 7 and Table 8).

Table : Sample Breakdown

Issue Category	Identical Matches		Approx. Matches		Overall Matches
	#	%	#	%	#	%
No Issue	50	96.1%	262	80.9%	312	83.0%
Need additional Health Topic.	1	1.9%	9	2.8%	10	2.7%
Delete Health Topic. Add Health Topic.	1	1.9%	21	6.5%	22	5.9%
Delete Health Topic.	0	0%	26	8.0%	26	6.9%
Delete Association	0	0%	6	1.9%	6	1.6%

Table : Approximate Mapping Issues and Examples

Category	ICD-9-CM Code	ICD-10-CM Code	Health Topics
No Issue	370.9 Unspecified keratitis	H16.9 Unspecified keratitis	Corneal Disorders
Need additional Health Topic.	984.9 Toxic effect of unspecified lead compound	M1A.10x1 Lead-induced chronic gout, unspecified site, with tophus (tophi)	Lead Poisoning [Add Gout]
Delete Health topic. Add Health topic.	V13.1 Personal history of trophoblastic disease	Z87.59 Personal history of other complications of pregnancy, childbirth, and the puerperium	Cancer and Pregnancy [Delete Cancer and Pregnancy. Add Pregnancy]
Delete Health Topic	989.5 Toxic effect of venom	T63.441A Toxic effect of venom of bees, accidental, initial encounter	Insect Bites and Stings, Animal Bites, Spider Bites [Delete Animal Bites & Spider Bites]
Delete Association	V58.2 Blood transfusion without reporting diagnosis	Z51.89 Encounter for other specified aftercare	Blood Transfusion and Donation [Delete completely]

The initial random sample of 376 codes also covered all chapters from the ICD-10-CM classification, also illustrated in Table 9. As previously seen in Figure 1, several chapters require more review to accommodate the increase in changes:

• 
  M00 – M99: Diseases of the musculoskeletal system and connective tissue
  
• 
  P00 - P96: Certain conditions originating in the perinatal period
  
• 
  S00 – T88: Injury, poisoning and certain other consequences of external causes
  
• 
  Z00 – Z99: Factors influencing health status and contact with health services
  

The sample review confirmed these findings and in addition found several chapters that contain significantly more issues than others, including those below. The following additional chapters comprised approximately 5% or more of the issues in the sample:

• 
  E00-E89: Endocrine, nutritional and metabolic diseases
  
• 
  K00-K94: Diseases of the digestive system
  
• 
  M00 – M99: Diseases of the musculoskeletal system and connective tissue
  
• 
  P00 - P96: Certain conditions originating in the perinatal period
  
• 
  S00 – T88: Injury, poisoning and certain other consequences of external causes
  
• 
  Z00 – Z99: Factors influencing health status and contact with health services
  

Table : Distribution of sample across ICD-10-CM chapters*

Category Code	Category Description	# in sample (% of sample)	# problems ( % of all problems)
A00 – B99	Certain infectious and parasitic diseases	20 (5.32%)	2 (3.1 %)
C00-D49	Neoplasms	19 (5.05%)	0 (0%)
D50-D89	Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism	4 (1.06%)	0 (0%)
E00-E89	Endocrine, nutritional, and metabolic diseases	9 (2.39%)	3 (4.7%)
F01-F99	Mental and behavioral disorders	7 (1.86%)	0 (0%)
G00 – G99	Diseases of the nervous system	6 (1.6%	1 (1.6%)
H00 – H59	Diseases of the eye and adnexa	15 (3.99%)	0 (0%)
H60 – H95	Diseases of the ear and mastoid process	3 (0.8%)	1 (1.6%)
I00 – I99	Diseases of the circulatory system	10 (2.66%)	0 (0%)
J00-J99	Diseases of the respiratory system	3 (0.8%)	0 (0%)
K00 – K94	Diseases of the digestive system	12 (3.19%)	3 (4.7%)
L00 – L99	Diseases of the skin and subcutaneous tissue	7 (1.86%)	2 (3.1%)
M00-M99	Diseases of the musculoskeletal system and connective tissue	28 (7.45%)	9 (14.1%)
N00 – N99	Diseases of the genitourinary system	10 (2.66%)	2 (3.1%)
O00 – O9A	Pregnancy, childbirth, and the puerperium	24 (6.38%)	3 (4.7%)
P00 – P96	Certain conditions originating in the perinatal period	5 (1.33%)	4 (6.3%)
Q00 – Q99	Congenital malformations, deformations and chromosomal abnormalities	11 (2.93%)	2 (3.1%)
R00-R99	Symptoms, signs and abnormal clinical and laboratory findings, NEC	7 (1.86%)	2 (3.1%)
S00-T88	Injury, poisoning and certain other consequences of external causes	155 (41.22%)	25 (39.1%)
V00-Y99	External causes of morbidity	3 (0.8%)	1 (1.6%)
Z00-Z99	Factors influencing health status and contact with health services	18 (4.79%)	4 (6.3%)

*Modified table from [6]

GEMS METHOD 2: GEMs SELECTIVE SAMPLE FROM S00 – T89

While the initial random sampling showed that the GEMs did provide an option to support 10-CM, we wanted to get a better idea of how the GEMs associated the Health Topics to ICD-10-CM codes within groupings or sections of ICD-10-CM. For this reason, the Associate Fellow analyzed a select sample of GEMs from the “Injury, poisoning, and certain other consequences of external causes” chapter because it contained the greatest number of issues and the greatest number of new codes. The Associate Fellow wanted to better determine patterns within code groupings and to review how mappings compare in relation to their ancestors and children.

The review of 1070 sample mappings from the S00-T89 chapter of the forward mapping ICD-9-CM to ICD-10-CM GEMs file¹⁰ allowed a more in-depth review of how mappings compare to their siblings, children, and cousins and to determine how the GEMs work within sections, or groupings, of ICD-10-CM. Groupings were selected from the different subsections of the S00 – T89 chapter. Similar categorizations were used to initially evaluate the individual mappings within each grouping (see Table 10). All codes from this sample mapped to MedlinePlus Health Topics.

Table : Issue Categories – Selective Sample

Category	Health Topics	ICD-9-CM	ICD-10-CM
No Problem	Fractures; Nose Disorders	802.0 Nasal bones, closed fracture	S02.2xxa Fracture of nasal bones, initial encounter for
			closed fracture
Delete Health Topic.	Fractures; Traumatic Brain Injuries (delete fractures)	804.60 Open fractures involving skull or face with other bones, with cerebral laceration and contusion, with state of consciousness unspecified	S06.330A Contusion and laceration of cerebrum, unspecified, without loss of consciousness, initial encounter
Delete Health Topic. Add Health Topic.	Dislocations; Wrist Injuries and Disorders (delete dislocations, add wounds)	833.13 Open dislocation of midcarpal (joint)	S615.09A Unspecified open wound of unspecified wrist, initial encounter
Need additional Health Topic	Fractures (add Neck Injuries and Disorders)	733.82 Nonunion of fracture	S12.001K Unspecified nondisplaced fracture of first cervical vertebra, subsequent encounter for fracture with nonunion
Delete Association	N/A	N/A	N/A

While the sample was not a true representative sample and therefore it is expected that additional problematic areas are found within the data, several types of codes within S00-T89 frequently encountered issues or demonstrated themes, as seen in Table 11.

Table : S00-T89 Select Issues

1	A substantial number of ICD-10-CM codes are not included in the forward mapping that the M+Connect team should review. These are available in the backward mapping file. Many of these missing codes include siblings of codes low within the hierarchy that can share Health Topics while others include codes higher up the hierarchy. For example, all codes until S00.02XA [Blister of scalp, initial encounter] are mapped but S00.03XA [Contusion of Scalp] and S00.04XA [External constriction of part of scalp] are not included.
2	Duplication occurs frequently when one ICD-10-CM code has multiple Health Topics, some unrelated, because of the different ICD-9-CM codes mapped to the one ICD-10-CM code. All the Health Topics previously assigned to the 9-CM codes are then mapped to the one 10-CM code. These 10-CM codes require manual review. While the different Health Topics can be appropriate, there are often instances when some of the Health Topics do not correctly map to the 10-CM code.
4	The distinction between “Wounds” and “Injuries” is problematic in the forward GEMs. Example: S01.309A [Unspecified open wound of unspecified ear, initial encounter] has Health Topics “Injuries” and “Ear Disorders”. “Wounds” is a better choice than “Injuries” in this case. Some of this can be fixed by mapping according to patterns in the codes and subsection headings. For example, S00 [Injury of head] and S01 [Open wound of head] both specify which general term is more applicable and can be applied to children.
6	Codes associated with the “Dislocation” Health Topic are generally problematic within this code subset. The GEMs map previous ICD-9-CM concepts that were dislocations to ICD-10-CM codes that are not for “Dislocations”. For example: ICD-9-CM code 830.1 [Open Dislocation of jaw] maps to ICD-10-CM code S01.409A [Unspecified open wound of specified cheek and temporomandibular area, initial encounter]. This frequently occurs when a Combination Flag is used. Therefore, a previous ICD-9-CM code for dislocation is now using two ICD-10-CM codes, one for dislocation, one for open wounds, etc.
7	Codes associated with Vertebral fractures are also problematic and similar to dislocations. 806.22 [Closed fracture of t1-t6 level with anterior cord syndrome] mapped to S22.019A [Unspecified fracture of first thoracic vertebra, initial encounter for closed fracture]. ICD-10-CM separates fractures and cord injuries.
8	Terms dealing with the leg (S70 – S99) often need one MedlinePlus Health Topic deleted. ICD-9-CM combined injuries to multiple parts of a leg while ICD-10-CM creates separate terms for each part of the leg. Ex: S81.809A [Unspecified open wound, unspecified lower leg, initial encounter] instead of 891.0 [Open wound of knee, leg except thigh, and ankle, without mention of complication]
9	General codes (e.g., T07 unspecified multiple injuries) are used for a variety of ICD-9-CM codes of unspecified location and can only be coded as Injuries, if coded at all.
10	The use of Traumatic Brain Injury and/or Concussion for head trauma should be reviewed. In addition, a Health Topic is needed to represent Head Injuries. Codes such as S01.00xA [Unspecified open wound of scalp, initial encounter] did not have an adequate location health topic beyond “Wounds”. In addition, the majority of head injuries are currently labeled as either Concussion or Traumatic Brain Injury. Other injuries occurring to the head that fall under neither concept would be better represented by “Head Injuries”.
11	T66 – T78 is much more specific in ICD-10-CM about the external cause (bugs, spiders, etc) of poisoning.
12	A Health Topic is needed to represent cold-related illnesses or cold weather injuries. Currently Hypothermia is the only one available and it is not suitable for conditions such as frost-bite.
13	A Health Topic other than UTI or Bladder Disease is needed to represent problems in the genital region.

Table : S00-T89 Select Themes

1	Codes that mapped to a M+ Health Topic for a condition but not anatomical location frequently need an additional health topic. While location Health Topics are not necessary to create a correct MedlinePlus Connect link, they can further enhance the mapping. Often, sections can use the same Health Topic, especially for anatomical location. For instance, S10 – S19 all involve injuries to the neck. All can use the Health topic “Neck Injuries and Disorders” as the secondary health topic term. Another primary health topic is recommended for the condition. This works the same way for other regions of the body, if there is a good Health topic for the anatomical location and the category is broad enough.
2	In general, contusions and bruises mapped well within each subset.
3	Concepts with a Combination flag tend to have more issues. While this is not always the case, these terms are more likely to include multiple ICD-10-CM codes for one ICD-9-CM code and therefore need to be prioritized.
4	The GEMs mappings are interesting in that they often did not apply to siblings of a term. For example, a mapping was provided for S01.109A [Unspecified open wound of scalp, initial encounter] but not for the additional encounters [S01.109D and S01.109S]. Additional encounters can always take the Health Topics used for the first encounter.

Reviewing concepts together also illuminated patterns useful for future mappings, especially when programming begins prior to the actual mapping. Patterns for S00 – T89 are available in Table 13. This table indicates patterns within the Injury and Poisoning chapter according to the code’s position in ICD-10-CM (as indicated by the number of characters). The patterns indicated in the first three levels with 3, 4, and 5 characters provide broad patterns that do not necessarily help reduce the amount of manual review. But if a code has 6 or more characters, the siblings and children of this code can have the same Health Topics applied since the only difference between them is the side of the body or the clinical visit (initial or subsequent). It is strongly recommended to review other chapters, especially those highlighted for growth or issues, for patterns. Using these patterns will help ease the burden of manual review.

Table : Format Patterns for S00-T89

Format	Format Patterns for S00-T89
XXX (3 characters)	Section of chapter indicated. No automated coding can occur at this high level that will populate to codes below because too broad.
XXX.X (4 characters)	Manual review required. Anatomical location (wrist, foot, etc.) often indicated. Can apply body location Health Topics to children. Diseases and specific conditions broad. Health Topics on conditions, etc. cannot generally be applied automatically.
XXX.XX (5 characters)	Specific condition indicated. Review suggested but children can often use same Health Topics as parents.
XXX.XXX (6 characters)	Laterality indicated. Automation recommended.
XXX.XXXX (7 characters)	Clinical visit type indicated. Automation recommended.

GEMs MASTER FILE

Lastly, the Associate Fellow created a master file containing both the forward and backward GEMs files to observe the differences between the two. The backward GEMs file mainly differs in terms of size since it includes new ICD-10-CM disease descriptions and clinical visit or Encounter codes (only first encounter included within most 910 gems). There are approximately 3 times as many code pairs in the backward GEMs file as the forward GEMs file. Figure 2 indicates the total number of code pairs per chapter as well as the number of codes contributed from each file. Based on this figure, the following chapters have significantly more codes from the backward mapping file:

• 
  H: Disease of the eye and adnexa; Diseases of the ear and mastoid process
  
• 
  I: Diseases of the circulatory system
  
• 
  L: Diseases of the skin and subcutaneous tissue
  
• 
  M: Diseases of the musculoskeletal system and connective tissue
  
• 
  O: Pregnancy, childbirth, and the puerperium
  
• 
  S & T: Injury, poisoning, and certain other consequences of external causes
  
• 
  V, W, X, Y: External causes of morbidity
  

Figure : Forward and backward size differences

A cursory scan for differences between the two files indicated that new disease descriptions from the backward GEMs file generally align with those from the forward GEMs file. As previously mentioned, encounter code mappings are frequently incorrect, at least within the S00-T98 chapter. While the first encounter is generally correct in both the forward and backward GEMs files, secondary and sequelae are often incorrect.

A subjective scan of the codes indicated that the two files do not align as well (numerous differences were seen between the two files) in the following chapters:

• 
  E: Endocrine, nutritional, and metabolic diseases
  
• 
  F: Mental and behavioral disorders
  
• 
  O: Pregnancy, childbirth, and the puerperium
  
• 
  M: Diseases of the musculoskeletal system and connective tissue
  
• 
  S &T: Injury, poisoning, and certain other consequences of external causes
  
• 
  Z: Factors influencing health status and contact with health services
  

If the GEMs are used, it is recommended that the team use this combined master file for review. Additional GEMs specific recommendations are available in the Recommendation section.