Sequelae, consequences and side effects
Advice on health categories
Research aimed at investigating sequelae of a specific pre-existing disease should be assigned equal percentage weighting to the primary existing condition and to the condition under investigation.
Studies of the side effects of a disease, where the condition under study is a downstream consequence of an original condition, are treated similarly.
Studies of the direct side effects of a disease treatment are usually coded in the same way.
In some cases, however, it may not be appropriate to code for the pre-existing disease.
e.g. If a particular disease is being used as an exemplar for studying the side effects of a treatment, such as studies of generalisable anti-nausea drugs.