“…Low response rates were evident in several studies, with less than half of the sample participating (Glosser et al, 1985;Fortinsky et al, 1995;Rice et al, 1997;Glasser and Miller, 1998;Heal and Husband, 1998;Bruce and Paterson, 2000;Knopman et al, 2000;Cody et al, 2002;Margiotta et al, 2002). Only three studies systematically analysed non-response (Bruce and Paterson, 2000;Van Hout et al, 2001;Wackerbarth and Johnson, 2002), and detailed information on response rates was not always provided (Newens et al, 1994;Alzheimer's Disease Society, 1995). Only one third of the studies using standardized questionnaires or interviews described pilot work (Chenoweth and Spencer, 1986;Brodaty et al, 1990;Brodaty et al, 1994;Wolff et al, 1995;Vassilas and Donaldson, 1998;Johnson et al, 2000;Sullivan and O'Conor, 2001;Van Hout et al, 2001;Wackerbarth and Johnson, 2002;Cody et al, 2002;Lindesay et al, 2002;VernooijDassen et al, 2003).…”