The distinction between primary and secondary diagnoses in medical coding and billing plays a vital role in determining the correct codes and ensuring accurate reimbursement. The primary diagnosis is the primary reason a patient seeks medical attention, while secondary diagnoses refer to additional conditions that are present but are not the primary reason for the visit or admission. The main diagnosis will be the reason the patient was admitted, or the reason the study or test was performed, the diagnosis or even any type of evaluation, the things, the reason the patient was admitted, the cause of it. You might not know it right away either. However, most of the time, the director, the head physician, and the inpatient have the same diagnosis, but that doesn't have to be the case.
For example, a patient may have leg pain, but upon evaluation it is discovered that he has bilateral pedal edema secondary to new-onset congestive heart failure that requires admission for further evaluation and treatment. While the primary complaint may have been leg pain, the diagnosis of new-onset congestive heart failure is more serious and would rank as the first diagnosis. Whenever a patient needs to be admitted to a hospital, the first diagnosis must clearly indicate the primary reason for admission. In the HCUP inpatient databases, the first diagnosis included is the primary diagnosis, defined as the condition established after the study as primarily responsible for causing the patient to be admitted to the hospital for care. In the HCUP outpatient databases, the first diagnosis is the condition, symptom or problem identified in the medical record and which is primarily responsible for the outpatient consultation.
For example, a patient who came to the emergency department with an acute but severe nosebleed (epistaxis) that had become too difficult to treat at home, went to the emergency department. Upon arrival, examination and obtaining a complete history of the patient, it was observed that the patient had been discharged after a recent hospital stay with coumadin, but that she had not undergone any follow-up or any tests to ensure adequate coagulation and that now her blood had become so thin that she was at risk of nosebleed. While in the emergency department, he had an episode of bloody diarrhea and additional tests revealed a ruptured previous gastric ulcer, increasing his risk of death and requiring additional resources for testing and treating a high-risk condition. In this context, the main diagnosis is probably bleeding gastric ulcer, which requires far more resources than acute epistaxis. If the diagnosis contains intermittent blank characters or is filled with zero, the diagnosis will be considered invalid.
The primary reason for the diagnosis must come first, with chronic diseases as secondary diagnoses. While you should report specific diagnostic codes when supported by available medical record documentation and clinical knowledge of the patient's health status, sometimes unspecified signs, symptoms, or codes are the most accurate code options. In some cases, the first diagnosis may be a symptom when the provider hasn't established (confirmed) the diagnosis. Knowing how to differentiate admission, primary, primary and secondary diagnoses for reporting and sequencing purposes can be intimidating and confusing.
For example, V22.0 or V22.1 can be used for routine antenatal visits without complications as a first diagnosis. Using the same example, the patient who had an acute episode of severe epistaxis, followed by a bleeding gastric ulcer, all caused by the uncontrolled use of anticoagulants (prescribed due to recent deep vein thrombosis), may also have an additional secondary diagnosis, such as hypertension or type 2 diabetes not related to the current condition. The rules of outpatient surgical procedures consist of assigning the diagnostic code to the condition in which the surgery was performed as the first on the list. In the absence of a definitive pathological diagnosis, the clinical diagnosis at the time of filing the claim should be used as the first-list diagnosis.
For example, a patient with chronic heart failure (secondary diagnosis) could be admitted for acute heart failure (primary diagnosis). If a patient has complications, such as sepsis due to surgery, sepsis should be coded as the primary diagnosis and the underlying condition (e.g., if several medical problems were addressed and several diagnoses are needed to reflect the complexity of the care provided), first list the most important or serious condition for which the patient received treatment. It should also be noted that it doesn't really matter what sequence the provider establishes when it comes to diagnosis A, B, C or D. The primary diagnosis is defined as the condition, after the study, that led to admission to the hospital, in accordance with the ICD-10-CM Official Coding and Information Guidelines.
