“…A single research group has used a prospective, longitudinal design to study participation outcomes in a sample of approximately 300 DTR members in 24 groups in New York City (Laudet et al, 2000a;Laudet et al, 2000b;Laudet, Cleland, Magura, Vogel, & Knight, 2004;Laudet, Magura, Cleland, Vogel, & Knight, 2003;Magura et al, 2007;Magura, Laudet, Mahmood, Rosenblum, & Knight, 2002;.…”