How fast does the Grim Reaper walk? Receiver operating characteristics curve analysis in healthy men aged 70 and over - Stanaway, F F; Gnjidic, D; Blyth, F M; Le Couteur, D G; Naganathan, V; Waite, L; Seibel, M J; Handelsman, D J; Sambrook, P N; Cumming, R G (BMJ, 2011)