‘Etiology’ and ‘Manifestation’ Home Health Coding on OASIS
In home health coding certain cases, ICD-9-CM guidelines require more than one diagnosis code to report a condition. The use of two diagnosis codes in is called “mandatory multiple coding,” “dual classification,” “dual coding,” or “mandatory dual coding.” One specific example of such mandatory dual coding is termed
“etiology/manifestation conventions” and involves the reporting of both a disease (the ‘cause’ or underlying problem) and one of its manifestations (the ‘effect’ or another condition caused by the problem).
Etiology’ versus ‘Manifestation’
The etiology ‘cause’ code is the underlying disease and must be listed first, before the code for a related manifestation. When a diagnosis is under consideration as an etiology diagnosis, the HHA is expected to ensure that a valid manifestation code is sequenced immediately following the assignment of the etiology code. The manifestation diagnosis is the relevant condition caused by the underlying disease and is never assigned as the patient’s primary diagnosis.
A good example…
Arthropathy 713.5 cannot be coded by itself. Arthopathy 713.5 is a ‘manifestation’ code and is always caused by another underlying problem. One cause of Arthopathy 713.5 is Diabetes 250.60. Hence, if you are using Arthopathy 713.5 on your M1022/4 list, you must list it UNDER the etiology code…250.60 will be listed ABOVE 713.5 on the list.
‘Dual coding’ rules apply to M1010, M1016 & M1022/4
Dual coding applies to the three diagnosis sections on the OASIS assessment: M1010, M1016 & M1022/4.
Refer to CMS Guidelines…
For supporting documentation please refer to CMS’s guide to home health diagnosis coding go https://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/HomeHealthQualityInits/downloads/HHQIAttachmentD.pdf