Table 3. Estimated number of patients who used Sleepio by population

		Estimated patients based on EMIS data		*Estimated patients based on Sleepio* data**
Population	Population size, n	n	%	n	%
EMIS sample	10 705	1008	9.42	Unknown^a	Unknown^a
Nine practices	129 865	1008^b	0.78^c	1220	0.94
Buckinghamshire	540 059	4192^c	0.78^c	3134	0.58
Thames Valley	2 300 000	17 940^c	0.78^c	12 374	0.54
England	55 980 000	434 512^c	0.78^c	302 292^c	0.54^b

^aUnknown represents the number of people across the EMIS sample who registered in the Sleepio app, which the authors were not able to observe because the two data sets could not be linked. ^bExtrapolated from observation. ^cAssumed from extrapolation.