Body Surface Area of Involvement (BSA)

Illustrates Domains


Illustrates Variables



This example shows the percentage of body surface area (BSA) affected by plaque psoriasis for a subject at each visit. The psoriasis condition itself is considered a clinical event; the evaluations of percentage BSA affected at specific time points were considered findings about the clinical event. Sponsors may represent findings data in a single FA dataset or split the FA domain into separate datasets, following guidance in the SDTMIG. In this example, an FACE dataset was used. A parent record in the Clinical Events (CE) domain is not required. The test, percentage BSA affected, is used where FAOBJ represents the disease of interest.

The palm method was used to determine the total area of involvement; this method is frequently used in psoriasis studies. An individual's hand, with or without digits, accounts for a small proportion of the total body surface. An individual's palm (not including fingers and wrist) accounts for about 0.5% of the individual's total body surface area. The entire palmar surface (including digits) accounts for about 1% of the individual's total body surface area. (CDISC Controlled Terminology). 

FALOC was populated with "SKIN" to indicate that all disease locations on the skin of the body were included. If the sponsor were to assess the BSA involvement on a specific body location, FALOC could be used to specify the location of interest. 

Because no parent record was included in CE, a RELREC dataset is not provided to link the FA domain to the parent domain.





Percent BSA Affected

Plaque psoriasis66%6666%SKINPALM METHODY1DAY 12012-09-30

Percent BSA Affected

Plaque psoriasis50%5050%SKINPALM METHOD
2WEEK 22012-10-15
3PS009FA2503BSAAFCTPPercent BSA AffectedPlaque psoriasis40%4040%SKINPALM METHOD
3WEEK 42012-10-30
4PS009FA2504BSAAFCTPPercent BSA AffectedPlaque psoriasis20%2020%SKINPALM METHOD
4WEEK 82012-11-30
5PS009FA2505BSAAFCTPPercent BSA AffectedPlaque psoriasis5%55%SKINPALM METHOD
5WEEK 162013-1-30