The Davison Attrition Index, {TAIL ~ DI}, is determined by {HEAD ~ the following procedure} 
The Davison Attrition Index , { TAIL ~ DI } , is determined by { HEAD ~ the following procedure }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD