I'm not sure I understand your question.
Tourette's Syndrome = Tics.

Do you mean how they impact quality of life in individuals?

The Yale Global Tic Severity Scale (YGTSS) is a clinician-rated scale that rates tic severity in tic disorders. It was originally developed by Leckman and others for use in studies.

Comorbid conditions have been found to affect quality of life in people who have Tourette's Syndrome.

Some people who have what they may call 'severe' tics actually can have a great quality of life, whereas others with 'mild' tics may find it more difficult. There are so many different factors that it would be very difficult to actually measure. Some people have a greater ability to deal with them and some don't. Some tics are painful. Some tics affect a person's ability to work. The list goes on. It's such an individual experience and no two people are the same.

A couple of examples very quickly below (there are many and they are varied) regarding how comorbid conditions can affect quality of life ( QOL ) . They just show how complex it can be to measure.

http://www.ncbi.nlm.nih.gov/pubmed/21506153
Mov Disord. 2011 Mar;26(4):735-8. doi: 10.1002/mds.23434. Epub 2010 Nov 10.
Clinical correlates of quality of life in Tourette syndrome

http://www.ncbi.nlm.nih.gov/pubmed/22038343
Eur Child Adolesc Psychiatry. 2012 Jan;21(1):5-13. doi: 10.1007/s00787-011-0223-z. Epub 2011 Oct 27.
Prevalence and clinical correlates of tic disorders in a community sample of school-age children.
Kraft JT1, Dalsgaard S, Obel C, Thomsen PH, Henriksen TB, Scahill L.