Results
Fifty seven analyses were included in the calculations. In general, there was a high degree of correlation between the TDI values calculated from the primary (original) and audit counts (Fig. 1) and there was also a strong relationship between the difference in TDI between the two counts and the Bray–Curtis similarity measure (Fig. 2). Sixty three percent of cases where the Bray–Curtis measure was >60% had a difference in TDI between primary and audit counts of