highly significantp<0.00001
The proportion of all cases who arrived with a referral slip declined continuously during this period (Row 8 of Table 1 ), from 71.9% at the beginning of implementation between April and June 2004 to 41.0% between July and September 2005, a trend which was highly significant (chi-square for linear trend=43.5, df=1, p<0.00001).