Comorbid Diagnosis

From CCMDB Wiki
Jump to navigationJump to search

For other diagnoses we collect see Admit Diagnosis or Acquired Diagnosis / Complication.

Comorbid Diagnoses are for diseases the patient has had for some time. Comorbidities can be a factor in increasing the patient risk of dying; see Charlson Comorbidity Index. A Comorbid Diagnosis is coded by setting the Dx_Type to "comorbid".

Collection Instructions


You will need to enter priorities for comorbids. For comorbids the priorities will only be used for grouping Combined ICD10 codes, not for prioritizing them in any order of importance.


Como Admit Acquired Primary Limits - this is part of that discussion - if we limit which admits will count as comos we need to review

  • SMW

  • Cargo

  • Categories

When to use Comorbid vs Admit Diagnosis or neither

When not to code a dx at all

  • Patient had the left lung removed 7 years ago. Code Past history, removal of all or part of lung
  • Patient has hypertension for which she takes medications and it is well controlled, but not related to the reasons for admission. Code this, because even if not part of the reason for the current admission, the hypertension IS relevant to this person's chronic medical situation and thus SHOULD be coded, as a comorbid.
  • Patient had ARDS (noncardiogenic pulmonary edema) a few years ago, and while ARDS is only an acute problem and thus is no longer active, his lungs never fully recovered and he has Respiratory failure (insufficiency), chronic which should be coded as a comorbid.
  • Chronic and ongoing old conditions should be coded -- as a comorbid if not part of the reason for this admission.

When to code an Admit Diagnosis

  • Dx was present prior to physical arrival in their bed on unit/ward
  • Dx is relevant to this admission in that it is either:
    • (a) an acute or exacerbated condition (as opposed to a chronic, stable condition -- e.g. stable diabetes), OR
    • (b) it is a condition not directly related to the reason(s) for admission, but its treatment is being actively managed -- and by actively we mean that during this admission changes are made to the management.
  • Examples:
  • Patient with TB has been treated for the past 5 (of his 9 expected) months admitted now for acute MI.
    • Scenario#1:No changes made in his TB treatment ---> so NOT an admit dx.
    • Scenario#2:Changes are made to his TB treatment during this admission ---> so IS an admit dx too

When to code a Comorbid Diagnosis

    • Dx is chronic and at its baseline situation, and was present prior to admission
    • Dx is in the past and is resolved and is included in one of the: Category: Past medical history codes
    • Code these even if the diagnosis of the condition was only made during the current hospital admission but it is quite clear that it must have existed before admission (even if that wasn't known). Here are some examples of that situation:
  • If a patient is admitted with pneumonia and on further workup is found to have CA of the lung, then this is coded in comorbid as it is obvious that the cancer must have been there for a while prior to admission.
  • Patient comes in with abdominal pain. Diagnosed as gastroenteritis but incidentally pt is found to be HIV +ve. You would code HIV +ve as a comorbid. Again, this is obvious that the pt had this problem for a while prior to admission to the hospital.

Some diagnoses can/should be coded as BOTH admit and comorbid

  • example: Patient who has been, and still is, being treated for active pulmonary TB as an outpatient, and is admitted for an acute MI. Here since on the current admission the TB is still being actively treated, it qualifies as an admit diagnosis, as above. But because it has been present from long before this admission, it also qualifies as an "active" comorbidity.
  • example: Patient has a past history of CHF and thus it should be coded as a comorbid. And if the CHF is worse at admission and it is part of the reason for admission, then CHF should also be an admit code too.

Recurrent conditions

  • Do not code a recurrent condition that is NOT currently present -- if currently active, include as Admit Diagnosis, otherwise don't code it
  • Recurrent pneumonia -- in between the infections, there IS NO pneumonia
  • Do code conditions that by nature have intermittent rather than continuous symptoms, but where the underlying condition doesn't go away.

Past medical history

Category:Past medical history contains codes that should only be captured as Comorbid Diagnosis that represent previous procedures or medical situations that can't be captured in another way. Their names usually follow the pattern "Past history of X" or "Artifical opening, has one".

Past medical history codes:

Controlling Dx Type for ICD10 codes

This wiki page talks about which ICD10 codes are allowed to be Comorbid vs. Acute vs. Acquired diagnosis type. See Controlling Dx Type for ICD10 codes for a discussion about cross-checks for these.

signs and symptoms should not be code as comorbidities

  • Signs, symptoms and findings (e.g. chest pain or dyspnea, or abnormal LFTs) should NOT be coded as comorbidities. Only real specific diagnoses should.

Patient has no comorbidities

If a patient has no comorbidities, enter No Comorbidities (ICD10 code).

Transfer of Comorbids on transfer between wards

See Patient copier button for more.

Data Integrity Checks (SMW)

Query check ICD10 dateCCMDB.accdbimplemented
Query check ICD10 Comorbids NoComo code but othersCCMDB.accdbimplemented

Related articles

Related articles: