OASIS Alert

Alzheimer's disease is only one possibility.

When an OASIS assessment includes the dementia diagnosis, you'll look for dementia ICD-9-CM codes in categories 290-294 (Organic psychotic conditions) of your coding manual. Here you'll see the five basic types of dementia: senile dementia, vascular dementia, alcoholic dementia, drug-induced dementia and dementia caused by other diseases such as Alzheimer's disease or Huntington's Chorea.

1. Nail down the specific cause. To do this you must get the background information on the patient, but the record may not document the cause. And if it's not documented, you can't code for it, says Donna Smith, director of health information management for Ethica Health and Retirement Communities in Gray, GA.

Reason: Some physicians will not clarify the type of dementia because it can only be determined after death or with specific testing that is not warranted or desired, says Charlotte Lefert, an independent health information management consultant in Madison, WI.

If all you have documented is the physician's diagnosis of dementia, use 294.8 (Other persistent mental disorders due to conditions classified elsewhere), says Lefert, who co-authored the American Health Information Management Association's text ICD-9-CM Diagnostic Coding for Long-Term Care and Home Care.

2. Don't automatically use 290.0. Medicare home health patients are often elderly, but don't assume you can list a senile dementia code, such as 290.0 (Senile dementia, uncomplicated). Even though people used to think that senility went along with getting older, don't code dementia as senile unless the doctor documents that, Smith says.

Example: An elderly patient may keep having little strokes and get more and more confused. But the strokes, rather than old age, are the cause of the dementia. Code this as 290.41 (Vascular dementia with delirium), Smith advises.

3. Scan the record for delusion or paranoia details. The documentation you have available may determine whether you need to use one or two codes for the dementia and delusions or paranoia, Lefert says. A diagnosis of senile dementia with delusion will allow you to report 290.2 (Senile dementia with delusional features). But a less specific diagnosis of dementia with delusions means you would code 294.8 and also 297.7 (Unspecified paranoid state) for the delusions, she explains.