From the 17-item DTS, the author and his colleagues developed a four-item PTSD screen scale for the detection of Post-Traumatic Stress Disorder. This scale, referred to as the SPAN, consists of the following four symptoms: Startle, Physiological Arousal, Anger and Numbing.
The principal references describing the development of this PTSD screen scale are as follows:
Davidson JR, Book SW, Colket JT, et al. Assessment of a new self-rating scale for post-traumatic stress disorder. Psychol Med. 1997; 27:153-160.
Meltzer-Brody S, Churchill E, Davidson JR. Derivation of the SPAN, a brief diagnostic screening test for post-traumatic stress disorder. Psychiatry Res. 1999; 88: 63-70.