Table 1 Definitions applied to the Hearing for Learning Initiative SW-CRT (see Fig. 1)

Cluster (unit of randomisation)

18 Northern Territory Aboriginal communities (clusters) allocated 2:4:4:4:4 to 5 start dates (sequences). Stratified by NT region (Top End or Central) and size (large or small)

Cluster period (a grouping of observations by time of measurement and cluster)

7 including baseline (i.e. 1 baseline, 5 training or transitions, and 6 Initiatives). Each cluster period has a duration of 6 months

Number of sequences

5 sequences. The order of sequence is 0111111, 0011111, 0001111, 0000111 and 0000011 (0 = control and 1 = initiative)

Number of clusters randomised to each sequence

Variable (2 in 1 sequence and 4 in 4 sequences)

Number of time periods

7 including baseline

Duration of time between each step

6 months

Transition period

3-month training period