“…Studies conducted in hospitals and multisite facilities showed that prevalence rates in Scandinavia vary from 3 to 14.8% (see Table 1) ( Peterson & Bittman, 1971; Abilgaard & Daugaard, 1979; Ek & Boman, 1982), from 5.3 to 19.7% elsewhere in Europe (most data from the UK) (Barbenel et al ., 1976; David et al ., 1983 ; Warner & Hall, 1986; Nyquist & Hawthorn, 1987; Dealey, 1991; Clark & Cullum, 1992; Allock et al 1994 ; Dealey, 1994; O'Dea, 1995), and from 4 to 23% in the USA and Canada ( Allman et al ., 1986 ; Shannon & Skorga, 1989; Langemo et al ., 1990 ; Meehan, 1990; Gawron, 1994; Bergstrom et al. 1995 ; McNaughton & Brazil, 1995).…”