combination codes
It is the same way in ICD-10 as well, but to an entirely different level. ICD-10-CM includes hundreds of combination codes, i.e. codes that link symptoms, manifestations or complications with a particular diagnosis. The coder will have to abstract information from the medical record to comply with the specificity. To report combination codes correctly, documentation must clearly indicate the presence of the symptom, manifestation, or complication along with the pertinent condition to which it corresponds. When a single combination code exists, coders should see to that they do not use multiple diagnosis codes, which clearly identifies all the aspects of the patient’s diagnosis.
A combination code is a single code used to classify one of the following in ICD 9:
Two diagnoses*
A diagnosis with an associated secondary process (manifestation)*
A diagnosis with an associated complication
Ways of identifying combination codes in ICD-10-CM:
- One way is the sub term entries in the Alphabetic Index.
- And second are the inclusion and exclusion notes in the Tabular List.
Combination codes should be only assigned when the coder fully identifies the diagnostic conditions involved. When the combination codes lack the necessary specificity to describe the manifestation or complication, an additional code might be useful in such cases. The instructional notes carried throughout the tabular index helps to remind you when an additional code may be necessary. It is always better to query the physician for clarification, if the documentation does not include all of the pertinent information to assign the combination code.
Few examples where ICD-10-CM has expanded combination coding for:
- Conditions and common symptoms or manifestations :
- E10.21 Type 1 diabetes mellitus with diabetic nephropathy
- I25.110 Atherosclerotic heart disease of native coronary artery with unstable angina pectoris
- K50.112 Crohn?s disease of large intestine with intestinal obstruction
- Codes for poisonings and external cause :
- T36.0x1D Poisoning by penicillins, accidental (unintentional), subsequent encounter
- T42.4x5A Adverse effect of benzodiazepines, initial encounter
- Following examples illustrate the details needed in the documentation:
- Diabetes Mellitus
- The type of diabetes must be documented.
- The body system affected must be identified.
- Complications affecting that body system should be included.
- Reviewing ICD-10 code categories E10 (Type 1 diabetes mellitus), E11 (Type 2 diabetes mellitus), and E13 (other specified diabetes mellitus), will help in familiarizing with the combination codes and the documentation.
- Hypertension:
- A causal relationship between hypertension and heart disease (if it exists) as ?due to hypertension? or ?hypertensive? must be documented.
- With chronic kidney disease: ICD-10-CM presumes a cause-and-effect relationship and classifies chronic kidney disease with hypertension as hypertensive chronic kidney disease.
- The stage of chronic kidney disease must be documented.
- Atherosclerotic coronary artery disease and angina:
- A causal relationship can be assumed in a patient with both atherosclerosis and angina pectoris. Eg : ICD-10 code I25.110 (arteriosclerotic heart disease of native coronary artery with unstable angina pectoris). In ICD-9, coders had to report two codes.
- If the angina is due to something other than the atherosclerosis it must be documented.
- A causal relationship can be assumed in a patient with both atherosclerosis and angina pectoris. Eg : ICD-10 code I25.110 (arteriosclerotic heart disease of native coronary artery with unstable angina pectoris). In ICD-9, coders had to report two codes.
- Pressure ulcers
- The site of the ulcer (including laterality) must be documented.
- The stage of the ulcer must be indicated.
- A new addition in ICD-10-CM is, the sacral region is uniquely identified. In ICD-9, that region is included in the code for lower back (707.03).
- Combination codes that include symptoms:
- The definitive diagnosis (if known) must be documented.
- The symptoms must be included
- ICD-10-CM contains a number of combination codes that identify both the definitive diagnosis and common symptoms of that diagnosis.
- An additional diagnosis should not be assigned for the symptoms, when using one of these combination codes.
- Adverse effects, poisoning, toxic effects, under dosing, and external causes:
- The type of drug (aspirin) must be documented.
- How the incident occurred (accidental or unintentional) must be indicated.
- The initial encouneter must be identified.
Reviewing the ICD-10 code category T36-T50 (poisoning by, adverse effects of, and underdosing of drugs, medicaments, and biological substances) will help to familiarize you with the combination codes in the category and identify where the additional code will be necessary.
- External cause codes:
- How the injury occurred (fall ? on same level as stumbling) must be documented.
- Sequential events that resulted in an injury (subsequent striking against sharp glass) must be documented.
- The initial encounter must be identified.
As coding productivity may be the main focus, it is also important to ensure the quality of data. For the sake of productivity standard, a medical record should not be just rushed through. Time should be spent in identifying the instances where the combination codes will be applicable. The data quality may suffer, when multiple codes are reported instead of a single combination code and hence delay in reimbursement.