Primary Care Coding Alert

Nugget: Code the treatment of ill effects from a medication after determining whether the medication was taken correctly or consumed in an improper manner. This will get the full reimbursement that is ethically due.

Family practices should code the treatment of ill effects from medication based on whether the correct medicine was taken, it was taken in the correct dosage and it was not combined with incompatible substances.

Late one morning, a woman rushes into your office with her adolescent son, who was recently diagnosed as diabetic and had begun using insulin to control the disease. The boy is experiencing extreme dizziness and complains of blurred vision. After the examination, the physician determines that the boy is reacting to the insulin.

The case seems fairly straightforward until you consider all of the diagnosis coding scenarios it represents. Reviewing the ICD-9 Table of Drugs and Chemicals causes more confusion. The table has six column heads poisoning, accident, therapeutic use, suicide attempt, assault and undetermined. Should you choose a poisoning code? Or would the E codes for therapeutic use be more appropriate? Should you assign multiple diagnosis codes to describe the symptoms and, if so, in what order should they appear?

There is no single, simple answer. A professional coder needs to consider the specific clinical situation and carefully review the physicians notes. To ensure proper reimbursement, follow these four steps:

Step 1 Determine Whether the Drug Was Taken Properly

Simply put, coders must be able to determine whether the patient took the medication correctly or consumed it in an improper manner, according to Kathryn Cianciolo, MA, RRA, CCS, CCS-P, chair of the Society for Clinical Coding in Waukesha, Wisc., and an independent medical practice management consultant. This is key to determining whether to code a poisoning or an adverse reaction, she points out.

The American Hospital Association (AHA) and ICD-9 clearly distinguish between the two, Cianciolo says, and specify that an adverse reaction to a prescribed drug not be coded as a poisoning unless the medication was taken in manner contrary to the physicians instructions.

If there is no immediate way to tell how the ill effect was caused, the condition would be classified as poisoning, points out Jeri Leong, RN, CPC, an independent medical practice management consultant and certified coding instructor in Honolulu. For instance, a patient might be brought into the office in a confused state and not coherent, making it impossible to determine if she took a prescribed medication correctly and is suffering an adverse reaction, or if she took too much of the drug. In this case, the coder would assign the appropriate poisoning code.

Step 2 Adverse Reaction: Code Symptoms First

If the patients condition is attributed to an adverse reaction, coders should first assign the diagnosis code that describes the manifestation or nature of the adverse reaction, Cianciolo advises.

For example, in the case of the adolescent boy who presented with light-headedness and blurred vision after taking a prescribed dose of insulin, coders first would report the symptoms: 780.4 (dizziness and giddiness, whirling sensations in the head with falling sensation, light-headedness) and 368.8 (other specified visual disturbance, blurred vision NOS).

Then, the coder would refer to the ICD-9 Table of Drugs and Chemicals and locate insulin. Because the drug had been prescribed and taken properly, the coder would assign E932.3 for therapeutic use.

Step 3 Poisoning: Report Poisoning Codes First

If the patient has taken the wrong drug, the wrong dosage or combined incompatible substances, the coder first will report the poisoning code for the drug taken, followed by symptom codes. If the diabetic boy in the example had injected the wrong dosage of insulin, the coder would refer to the Table of Drugs and Chemical, find insulin and report the code that appears in the poisoning column 962.3. In addition, the coder would assign codes for the signs and symptoms the boy exhibited dizziness (780.4) and blurred vision (368.8).

Finally, the coder would choose the appropriate E code to indicate the external cause of the poisoning, which might include assault, accidental ingestion or suicide attempt. In the example given, the inexperienced diabetic patient inadvertently may have taken the wrong dosage, and so the coder would assign E858.0 (accidental poisoning by hormones and synthetic substitutes).

Leong points out that many carriers do not require that physicians assign an E code reporting a poisoning. However, I encourage all coders to use these E codes for external causes even if the payer considers it optional, she says. These codes help to clarify the incident and provide accurate statistics.

Editors Note: Coders should be clear that the therapeutic use E code is required when coding an adverse reaction. Also take care not to confuse the E codes that are assigned for therapeutic use when a patients ill effect is caused by an adverse reaction with the E codes that describe the external cause in poisoning cases. Therapeutic use codes should not be assigned in poisoning cases.

Step 4 Code Late Effects/Immediate Reaction

Cianciolo notes that late effects the effects that continue to affect the patient after the acute phase of the reaction has passed also need to be reported. For instance, once the dizziness and blurred vision have been corrected, the diabetic patient may continue to suffer from a moderate headache. When this occurs, you would assign a late effect code first. The correct sequence in this event would be:

Code the residual or remaining effect first (e.g., headache 784.0);

Assign the late effect code 909.5 (late effect or adverse effect of drug, medical or biological substance) or 909.0 (late effect of poisoning due to drug, medicinal, or biological substance);

Code the drug effect the same as with the immediate drug reaction (i.e., signs and symptoms for adverse reactions, poisoning codes from the Table of Drugs and Chemicals in poisoning cases).

Coding Specific Scenarios

Scenario One: An unconscious child is brought into the office after accidentally ingesting a bottle of aspirin. The following ICD-9 codes should be assigned:

965.1 (poisoning by salicylates)

780.09 (other alteration of consciousness)

E850.3 (accidental poisoning by salicylates)

Scenario Two: A patient is given Chlorpromazine for severe nausea and vomiting. The patient takes the drug according to instructions but, after a short time, develops vertigo and headache. She returns to the physician for a change of medication. The following ICD-9 codes should be assigned:

780.4 (vertigo)

784.0 (headache)

E939.1 (adverse effects in therapeutic use, phenothiazine-based tranquilizers)

Be sure to code each of the three factors to avoid getting less than optimum reimbursement for the treatment.

Adverse Reaction and Poisoning Adverse reaction: Guidelines state that an adverse reaction occurs only when a medication is correctly prescribed, properly administered and nonetheless causes the patient to suffer an ill effect. Examples of adverse reactions include hypersensitivity, allergic reactions, interactions between prescribed drugs, side effects, accumulative effects (drug toxicity), and idiosyncratic, synergistic and paradoxical effects. Cianciolo points out that chronic effects of a drug that has been taken over a long period of time and is still being taken at the time of the ill effects also are considered adverse reactions. Poisoning: Conversely, poisoning is defined as the reaction caused by drugs, medication or other substances that are not used in accordance with a physicians instructions. Examples of poisonings include overdose, suicide attempts, wrong dosage given/taken, the combination of alcohol and a medication (either prescription or non-prescription), the combination of a prescribed drug taken with an over-the-counter medication or illegal drug use or intoxication other than cumulative effect (i.e., alcoholic cirrhosis of the liver -- 571.2).