Principal diagnosis UHDDS (http://www.eicd.com/guidelines/PrincipalDx.htm)
is the condition "established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care."
Codes for symptoms, signs, and ill-defined conditions:
Codes for symptoms, signs, and ill-defined conditions from Chapter 16 are not to be used as the principal diagnosis when a related definitive diagnosis has been established.
Two or more interrelated conditions, each potentially meeting the definition for principal diagnosis:
When there are two or more interrelated conditions (such as diseases in the same ICD-9-CM chapter, or manifestations characteristically associated with a certain disease) potentially meeting the definition of principal diagnosis, either condition may be sequenced first, unless the circumstances of the admission, the therapy provided,the Tabular List, or the Alphabetic Index indicates otherwise.
Two or more diagnoses that equally meet the definition for principal diagnosis:
In the unusual instance when two or more dignoses equally meet the criteria for principal diagnosis, as determined by the circumstances of admission, diagnostic workup, and/or the therapy provided, and the Alphabetic Index, Tabular List, or another coding guideline does not provide sequencing direction is such cases, any one of the diagnosis may be sequenced first.
Two or more comparative or contrasting conditions:
In those rare instances when two or more contrasting or comparative diagnoses are documented as "either/or" (or similar terminology), they are coded as if confirmed and sequenced according to the circumstances of the admission. If no further determination can be made as to which diagnosis is principal, either diagnosis may be sequenced first.
A symptom(s) followed by contrasting or comparative diagnoses:
When a symptom(s) is (are) followed by contrasting or comparative diagnoses, the symptom code is sequenced first. All the contrasting and comparative diagnoses should be coded as additional diagnoses.
Original treatment plan not carried out:
Sequence as the principal diagnosis the condition that after study occasioned the admission to the hospital, even if treatment may not have been carried out due to unforeseen circumstances. (Use V-code as additional code to show procedure was not carried out.)
Complications of surgery and other medical care:
When the admission is for treatment of a complication resulting from surgery or other medical care, the complication code is sequenced as the principal diagnosis. If the complication is classified to 996 through 999 series, and the code lacks the necessary specificity in describing the complication, an additional code for the specific complication should be assigned.
If the diagnosis is documented at the time of discharge is qualified as "probable", "suspected", "likely", "questionable", "possible", or "still to be ruled out", or other similar terms indicating uncertainty, code the condition as if it existed or was established. This guideline is applicable only to inpatient admissions.
Admission from observation unit: Admission following medical observation.
When a patient is admitted to an observation unit for a medical condition, which either worsens or does not improve, and is subsequently admitted as an inpatient of the same hospital for this same medical condition, the principal diagnosis would be the medical condition that led to the hospital admission.
Admission from observation unit: Admission following postoperative observation.
When a patient is admitted to an observation unit to monitor a condition (or complication) that develops following outpatient surgery, and then is subsequently admitted as an inpatient of the same hospital, hospitals should apply the UHDDS definition of principal diagnosis.
Admission from outpatient surgery: When patient receives surgery in the hospital's outpatient surgery department and is subsequently admitted. 1/3
1. When the reason for the inpatient admission is a complication, assign the complication as the principal diagnosis.
Admission from outpatient surgery: When patient receives surgery in the hospital's outpatient surgery department and is subsequently admitted. 2/3
2. When no complication, or other condition, is documented as the reason for the inpatient admission, assign the reason for the outpatient surgery as the principal diagnosis.
Admission from outpatient surgery: When patient receives surgery in the hospital's outpatient surgery department and is subsequently admitted. 3/3
3. When the reason for the inpatient admission is another condition unrelated to the surgery, assign the unrelated condition as the principal diagnosis.
If the provider has included a diagnosis in the final diagnostic statement, such as the discharge summary or the face sheet, the diagnosis should ordinarily be coded. Some providers include in the diagnostic statement resolved conditions or diagnoses and status post procedures from a previous admission that have not bearing on the current stay. Such conditions are not to be reported and are coded only if required by hospital policy. However history codes may be used if has an impact on current care or influences treatment.
Abnormal findings (lab, xray, path, and other diagnostic results) are not coded and reported unless the provider indicates their clinical significance. This differs from the coding practices in the outpatient setting for coding encounter for diagnostic tests that have been interpreted by a provider.