Table 3.

Association between smartphone use and CTS

Factor	Levels	Controls		Cases		OR	P	95% CI
		n=190	%	n=95	%			LB	UB
Average number of hours per day of smartphone use	1 h or less	11	52.40	10	47.60		0.001	Reference
	2-3 h	38	52.10	35	47.90	5.568	0.003	1.787	17.352
	4-5 h	56	63.60	32	36.40	5.641	0.000	2.347	13.563
	6-7 h	36	78.30	10	21.70	3.5	0.005	1.475	8.308
	8 h or more	49	86.00	8	14.00	1.701	0.309	0.611	4.739
Average number of days per week of smartphone use	5 days or less	4	2.1	5	5.3	2.583	0.151	0.677	9.853
	>5 days	186	97.9	90	94.7	Reference
Average number of years smartphone use	<3 years	2	1.1	1	1.1	1.000	1.000	0.090	11.170
	3 years or more	188	98.9	94	98.9	Reference
Number of hands used to hold the smartphone*	One hand	135	71.10	57	60.00	Reference
	Two hands	55	28.90	38	50.00	7.766	0.001	2.431	24.811
Main purpose for smartphone use
Typing/editing text	No	136	71.6	59	62.1	Reference
	Yes	54	28.4	36	37.9	1.537	0.106	0.913	2.587
Chatting	No	51	26.8	8	8.4	Reference
	Yes	139	73.2	87	91.6	3.99	0.001	1.807	8.81
Searching the web	No	50	26.3	25	26.3	Reference
	Yes	140	73.7	70	73.7	1	1	0.572	1.749
Playing games	No	149	78.4	93	97.9	Reference
	Yes	41	21.6	2	2.1	0.078	0.001	0.018	0.331
Taking photos	No	114	60.0	81	85.3	Reference
	Yes	76	40.0	14	14.7	0.259	0.000	0.137	0.49
Watching movies	No	141	74.2	76	80.0	Reference
	Yes	49	25.8	19	20.0	0.719	0.281	0.395	1.309
Reading	No	81	42.6	73	76.8	Reference
	Yes	109	57.4	22	23.2	0.224	0.000	0.128	0.391
Listening to music/podcasts	No	139	73.2	91	95.8	Reference
	Yes	51	26.8	4	4.2	0.12	0.000	0.042	0.343
Drawing/creating graphics	No	184	96.8	95	100.0	Reference
	Yes	6	3.2	0	0.0	0	0.999	0

*Adjusted for number of hours of use/day