Table 3.

Comparison of qualified rate and bacterial load of mobile phones according to demographic characteristics and usages

Characteristics and usage	No. of HCWs (N = 111)	No. of qualified	Qualified rate (%)	χ2	p	Median No. of colonies (IQR) (CFU/cm2)	Z	p
Age
< 35 years	67	51	76.1	1.75	0.185	3.4 (0.8–8.4)	− 2.00	0.048
≥ 35 years	44	38	86.4			1.4 (0.5–4.7)
Gender
Male	14	8	57.1	5.35	0.021	8.9 (3.5–20.9)	2.94	0.004
Female	97	81	83.5			1.9 (0.7–4.9)
Environment
I	26	19	73.1	2.06	0.560	2.0 (0.4–5.5)	2.64a	0.450
II	32	25	78.1			1.7 (0.8–4.1)
III	27	22	81.5			3.5 (1.1–8.2)
IV	26	23	88.5			3.4 (0.6–5.9)
Profession
Nurse	85	72	84.7	4.68	0.031	2.1 (0.7–4.9)	2.03	0.045
Non nurse	26	17	65.4			4.2 (0.8–15.6)
Educational level
Bachelor’s degree below	43	33	76.7	0.52	0.470	2.9 (0.7–7.2)	0.44	0.662
Bachelor's degree or above	68	56	82.4			2.7 (0.7–6.6)
Frequency of utilization
Once every 5 min	12	7	58.3	9.09	0.028	4.7 (0.5–18.1)	12.79a	0.005
Once every 5–30 min	24	20	83.3			3.4 (0.5–6.4)
Once every 30–60 min	30	21	70.0			4.6 (1.4–13.4)
Usually not, only when having calls	45	41	91.1			1.4 (0.6–2.9)
Use of a phone cover
Yes	78	59	75.6	3.40	0.065	3.2 (1.2–8.2)	− 2.59	0.011
No	33	30	90.9			0.8 (0.4–3.8)

IQR interquartile range; CFU colony-forming unit

^a The χ² of Kruskal–Wallis test