Table 6.

Characteristics of included trials of pulsed electromagnetic fields for pain relief in patients with knee osteoarthritis

First author, publication year	Intervention type, treatment sessions and period	No of patients on active therapy (n = 255)	Method quality	Mean baseline pain (mm VAS)	Best mean difference (95% CI) of change over placebo (mm VAS)	Outcome assessment timepoints (weeks, best time point in bold)
Callaghan-05	SWT, 3 sessions/week, 6 sessions total, output 20 W in 20 minutes, 400 Hz, treatment dose 24 kJ	9	5	65.0	15.0 (-12.7 to 42.7)	2
Jacobson – 01	PEMF, 8 sessions, 1–8 Hz, 3 × 10-7G	101	3	63.3	7.9 (0.8 to 15.4)	2, 4
Nicolakis-02	PEMF 30 min daily, 6 weeks, 40 mT 1–3000 Hz	15	4	34.6	10.8 (-3.5 to 25.1)	6
Pipitone-01	PEMF 30 min daily, 6 weeks, 3–20 Hz, <0.5 Gauss	34	5	-	2.0 (-5.8 to 9.7)	6
Thamsborg-05	PEMF, 2 h daily for 6 weeks, 10 mV, 50 Hz	42	5	52.6	0.3 (-7.7 to 7.9)	2, 6, 12
Trock-93	PEMF, 15 Gauss, <30 Hz, 30 min 3–5 times/week, total 18 sessions	14	4	76.5	31.0 (11.0 to 51.0)	2,4, 8
Trock-94	PEMF, 15 Gauss, <30 Hz, 30 min 3–5 times/week, total 18 sessions	40	5	70.7	14.6 (0.9 to 28.3)	2, 4, 8
Best within 4 weeks		209			6.9† (2.2 to 11.6)
6 weeks		91			1.0 (-4.1 to 6.0)
8 weeks		47			19.8 (7.1 to 32.5)
12 weeks		42			-2.4 (-10.1 to 5.3)
Pooled 6–12 weeks		180			4.8 (-2.2 to 11.8)
Total		255	4.4*	63.7†		3.2*

*Mean † Weighted mean