The review concluded that there was strong evidence to suggest that pulsed electromagnetic energy had a positive effect on the rate of wound healing. Methodological flaws in all the included trials suggest this conclusion is over-optimistic and should be interpreted with caution.

To assess the effectiveness of pulsed electromagnetic energy on the healing of chronic wounds (including exploration of optimum treatment regimes).

CINAHL, EMBASE, DARE, PubMed, Cochrane Database of Systematic Reviews, Cochrane Wounds Group Specialised Register and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to December 2008 without language restrictions; search terms were reported. Reference lists of selected studies were searched.

Any type of clinical trial of adults (aged 18 or over) diagnosed with a chronic ulcer who received any form of pulsed electromagnetic therapy for healing any type of wound were eligible for inclusion if they compared with sham or a different intensity of pulsed electromagnetic therapy, no pulsed electromagnetic therapy or other treatments. Primary outcomes were time to complete healing, proportion of wound healed within the trial period and rate of change in wound size.

Study participants had venous ulcers, pressure ulcers or chronic plantar ulcers. Patient ages ranged from 20 to 101 years. The form of electromagnetic energy applied varied. Duration (range 15 minutes to four hours) and frequency (range two to 14 per week) of treatments varied. Most comparator groups received a sham treatment. Mean ulcer surface area was the most common outcome measure.

Two reviewers independently selected studies for inclusion. Disagreements were resolved by discussion or by a third reviewer.

Study quality was evaluated using 11 criteria to assess: randomisation, allocation concealment, group similarity at baseline, blinding, use of cointerventions, compliance, drop-outs, group similarity for outcome assessment time points and use of intention-to-treat analyses. Studies received a score out of 11. Trials that scored 6 or more were deemed high quality.

The authors did not state how many reviewers performed the quality assessment.

The authors stated that data were independently extracted.

A narrative synthesis was presented, grouped by type of ulcer.

Eleven trials (n=360, sample size range 19 to 86) were included in the review. Study quality scores ranged from 1 to 9 out of 11 (mean 5.5). Only three studies used a satisfactory method of randomisation. Only one study used concealed allocation of treatment. Groups in eight studies were not comparable at baseline (or this was not stated). Six studies were deemed high quality and five low quality.

Venous ulcers (six trials): Four of five studies that compared pulsed electromagnetic energy with sham reported a statistically significant difference favouring active treatment (on a range of outcomes); three of these four studies were deemed to be of high quality.

Pressure ulcers (four trials): One high-quality study found a statistically significant difference that favoured active treatment over sham for the percentage of ulcer healed at one week, median size of ulcer at one week and median days to complete healing. Three low-quality studies concluded that pulsed electromagnetic energy was a safe treatment that accelerated healing.

Plantar ulcers (one trial): This study concluded that treatment with pulsed electromagnetic fields led to a substantially more rapid rate of healing of the ulcers than in patients who received conventional wound treatment only.

There was strong evidence to suggest that pulsed electromagnetic energy had a positive effect on the rate of wound healing; the degree to which it was clinically significant was less conclusive.

The review addressed a clear question and was supported by appropriate inclusion criteria. Attempts to identify studies in any language were undertaken by searching electronic databases and checking references. It appeared that no systematic search was made to identify unpublished studies. It appeared that suitable methods were used to reduce risks of reviewer error and bias for the processes of data extraction and study selection; the authors did not report on whether such methods were used to assess study quality.

Sufficient study details were provided and an appropriate narrative synthesis of data was undertaken (considering the heterogeneity between studies). Study quality was assessed and was used in interpreting the results of the review. However, the award of high-quality status to studies with methodological and/or reporting flaws appeared questionable. The authors did discuss study quality issues and also exercised caution in relating the review results to clinical practice. However, their conclusion of strong evidence for improved rate of wound healing appeared somewhat over-optimistic considering all the studies were small and all appeared to have methodological flaws that could impact on the reliability of results. In light of this, the authors' conclusions should be interpreted with caution.

Practice: The authors stated that due to the heterogeneous nature of the interventions and numerous methodological flaws they could make no definitive recommendations for clinical practice.

Research: The authors stated that future randomised trials should be more vigilant in their methodological quality, particularly the method of randomisation used, inclusion of intention-to-treat analysis and concealment of treatment allocation. Issues of baseline comparability, blinding the care provider and sample sizes needed to be addressed. All methods should be thoroughly reported to allow more accurate evaluation. Trials should include outcome measures that promoted homogeneity and comparability between studies. Assessments should be carried out over prolonged periods to determine long-term effects. Trials should also try to assess ulcers of similar origin, duration and size.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.