Table 1

Phase 1 follow-up diagnostic assessment sampling strategy, with study numbers

Sampling group	Observed Q-CHAT (missing items=0)	Maximum Q-CHAT (missing items=4)	% sampled	Total	Assessment numbers
Sampling group	Observed Q-CHAT (missing items=0)	Maximum Q-CHAT (missing items=4)	% sampled	Total	Selected	Invited	Agreed
1	≥38	≥44	100	86	86	74	40
2	≤37	≥44	50	21	10	9	6
3	41–43	41–43	50	61	31	28	16
4	≤40	41–43	50	21	10	8	5
5	38–40	38–40	25	129	31	28	20
6	≤37	38–40	25	25	5	5	2
7	≤37	≤37	1	3300	40	39	32
Total				3643	213	191	121