Table 1

Univariate negative binomial regression testing the association of key independent variables with how frequently the user activated the app per 30 days. Frequency of app use was calculated using the methodology described in the supplementary appendix

Characteristic	N (users)	Estimated mean number of app uses per 30 days and 95% CI			Univariate p value	Directionality versus reference category
			Low	High
Country income	n=18 312				Overall variable p<0.001
Low income	558	24.0	22.0	26.2	Reference category
Lower middle income	5633	17.4	17.0	17.9	<0.001	Less use
Upper middle income	6376	15.5	15.1	15.9	<0.001	Less use
High income	5745	12.2	11.9	12.6	<0.001	Less use
Provider type	n=12 798				Overall variable p<0.001
Physician	3571	14.1	13.6	14.6	Reference category
Physician trainee	2879	16.3	15.7	17.0	<0.001	More use
Medical student	492	21.3	19.4	23.5	<0.001	More use
AA or CRNA	3200	16.2	15.6	16.8	<0.001	More use
AA or CRNA Trainee	532	19.1	17.5	20.9	<0.001	More use
Anaesthesia technician/technically trained	1018	19.5	18.3	20.8	<0.001	More use
All others	1106	15.2	14.3	16.2	0.033	More use
Importance (binomial)	n=7205				Overall variable p<0.001
Absolutely essential/very important	3466	18.2	17.5	18.8	Reference category
Average or below	3739	16.4	15.9	17.0	<0.001	Less use
Length of practice	n=4700				Overall variable p<0.001
0–5 years	1948	16.2	15.4	16.9	Reference category
6–10 years	929	12.0	11.2	12.9	<0.001	Less use
11–20 years	786	12.4	11.5	13.3	<0.001	Less use
>21 years	1037	15.2	14.2	16.2	NS	–
Practice size (grouped)	n=7484				Overall variable p<0.001
Solo	3389	13.5	13.0	14.0	Reference category
Small group<10	1784	15.1	14.4	15.8	<0.001	More use
Medium group 10–25	780	12.8	12.0	13.8	NS	–
Large group >25	1531	13.5	12.8	14.2	NS	–
Practice model	n=5988				Overall variable p<0.01
Physician only	1834	13.5	12.9	14.1	Reference category
Physician supervised, anaesthesiologist on site	2666	13.4	12.9	13.9	NS	–
Physician supervised, non-anaesthesiologist on site	478	13.8	12.7	15.1	NS	–
Physician supervised, no physician on site	278	16.4	14.7	18.5	<0.01	More use
No physician supervision	424	13.0	11.8	14.3	NS	–
Not an anaesthesia provider	308	15.3	13.7	17.1	0.033	More use
Primary community served	n=3629				Overall variable p=0.014
Urban	2050	15.3	14.7	16.0	Reference category
Suburban	662	15.0	13.9	16.2	NS	–
Rural	917	17.0	15.9	18.1	<0.01	More use
Practice type	n=6298				Overall variable NS
Private clinic or office	1138	14.3	13.5	15.2	Reference category
Local health clinic	527	14.0	12.8	15.2	NS	–
Ambulatory surgery centre	362	13.5	12.2	15.0	NS	–
Small community hospital	772	12.8	12.0	13.7	0.015	Less use
Large community hospital	1811	13.7	13.1	14.4	NS	–
Academic department/university hospital	1688	14.0	13.3	14.6	NS	–

AA, anaesthesiologist assistants; CRNA, certified registered nurse anaesthetists.