Table 3 Cox proportional hazards regression (n = 160)

10 mL volume (referent: 3 mL)

1.56 (0.97–2.50)*

^f

6 hr frequency (referent = 24 h)

1.58 (0.99–2.53)*

^f

Interaction of volume and frequency^a

0.54 (0.21–1.42)

^f

Age (one year increase)

1.00 (0.99,1.02)

^f

Gender (female)

1.90 (1.18,3.05)***

2.17 (1.33,3.55)***

Weight (over/obese)

1.29 (0.81,2.05)

^f

Comorbidities (one category higher)^b

1.03 (0.78,1.35)

^f

Insertion on dominant side

1.67 (1.01,2.76)**

^f

Infection at baseline (any)

1.56 (0.93,2.59)*

^f

Antibiotics at baseline (yes)

0.99 (0.60,1.64)

^f

IV treatment at baseline (yes)

0.95 (0.43,2.07)

^f

Insertion at hand/posterior wrist^c

1.67 (1.04,2.70)**

1.66 (1.02,2.69)**

Insertion at forearm^a

0.58 (0.35,0.97)**

^e

Insertion at cub. fossa/ant. upper arm^c

1.01 (0.53,1.93)

^f

Inserted by IV service^c

0.95 (0.59,1.52)

^f

Inserted by nurse^c

2.01 (1.11,3.63)**

^f

Size (20 g versus 22 g)

1.14 (0.70,1.87)

^f

Vein quality (poor)

1.26 (0.79,2.01)

^f

Multiple insertion attempts (yes)

1.32 (0.78,2.23)

^f

Extension tubing (yes)

1.25 (0.78,1.98)

^f

3-way tap (yes)

1.33 (0.79,2.24)

^f

IV treatment at device removal (yes)

2.61 (1.28,5.29)***

^e

IV treatment rate at device removal^d

1.40 (1.07,1.82)**

^e

IV antibiotics at device removal (yes)

2.07 (1.27,3.38)***

^e

IV antibiotics rate at device removal^d

1.33 (1.09,1.62)***

^e

Medication types administered:

- antibiotics^c

1.12 (0.67,1.87)

^f

- cephalosporins^c

0.80 (0.49,1.32)

^f

- penicillin combination^c

0.75 (0.40,1.41)

^f

Episode rate (medications and flushes)

1.22 (1.08,1.38)***

1.25 (1.10,1.41)***