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. 2020 Jan 22;2020(1):CD012196. doi: 10.1002/14651858.CD012196.pub2

Wood 1993.

Methods Design: 8‐week multicentred, placebo, randomised controlled study
Participants Health condition: people with chronic decubitus ulcers
Sample size:

  • Randomisation: at ulcer level (more than one ulcer for some participants)§

  • Randomised (participants, n; ulcers, n): 71; 74

    • Experimental: 41; 43

    • Control: 30; 31

  • Analysed (participants, n; ulcers, n): 66; 66

    • Experimental: 41; 41

    • Control: 25; 25


Setting, country: medical centre (4 sites), USA
Inclusion criteria:

  • patients with chronic decubitus ulcers with no significant improvement to standard nursing practice for more than 5 weeks

  • stage II, III and IV decubitus ulcers


Exclusion criteria:

  • patients on steroids or drugs known to influence wound healing


Characteristics of pressure ulcer:

  • Experimental

    • Ulcer duration: 5.5 months (5.2)

    • Ulcer location: coccyx (9), buttock (5), hip (10), leg (4), ankle (5), toe (3)

    • Ulcer stage (n): stage II, III and IV (not reported)

  • Control

    • Ulcer duration: 4.9 months (4.1)

    • Ulcer location: coccyx (7), buttock (5), hip (2), leg (2), ankle (1), toe (2)

    • Ulcer stage (n): stage II, III and IV (not reported)


Mean age (SD):

  • Experimental: 76 years (13)

  • Control: 75 years (15)


Gender:

  • Experimental: 63% male

  • Control: 50% male


§The number of pressure ulcers is greater than the number of participants but it is not clearly stated whether participants or pressure ulcers were randomised. However, the authors provided the individual participant data and from this it appears that pressure ulcers (not participants) were randomised.
Interventions Total groups in this study: two
Experimental: PLIDC (treated ulcer) and standard treatment

  • Duration: single application duration not reported; 3 times alternate days i.e. 3 sessions per week; for large ulcers more than 3 times; for 8 weeks

  • Electrode placement: both electrode were placed 2 centimetres around the wound margins

  • Device, Manufacturer: PLIDC instrument, MEMS CS 600, Harbor Medical Inc. USA

  • Intensity of ES: not reported

  • Frequency: 0.8 Hz

  • Type of current: pulsed

  • Polarity: not reported


Control: control group and standard treatment

  • Sham instrument with no ES delivered


Standard treatment for both groups

  • This includes wound cleansing, simple moist dressings and whirlpool baths
Outcomes Outcomes included in this review: presented as [name of outcome in review]‐ [name of outcome in study]

  • Proportion of pressure ulcers healed ‐ ulcers healed (expressed as numbers)

  • Surface area of pressure ulcers ‐ area of ulcer (expressed as cm2)

  • Rate of pressure ulcer healing ‐ percentage healing of pressure ulcers (expressed as percentage per week)


Other outcomes:

  • Ulcer depth


Time point included in this review: week 8 (end of intervention)
Other time point: baseline
Notes Withdrawals, (n; reason):

  • Experimental: 2; died

  • Control: 4; died, 2; lost to follow‐up (reason not specified)


Funding source: this study is supported by:

  • Veterans Administration Hospitals

  • University of Minnnesota

  • University of Hamburg

  • Harbor Medical Inc., Minneapolis, USA


Trial registration or published protocol: no information about trial registration or published protocol provided
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Quote: "randomly assigned" p1000
 Comment: insufficient detail reported
Allocation concealment (selection bias) Unclear risk Comment: insufficient detail reported
Blinding of participants (performance bias) 
 All outcomes Low risk Quote: control participants received "….sham instrument." p1000
Blinding of personnel (performance bias) 
 All outcomes Low risk Quote: "All treatments were given by the same investigator, at each of the four facilities, without the investigator knowing which was the active or sham instrument." p1000
 Comment: personnel were blinded
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk Quote: "Surface area tracings and photographs of the ulcers were controlled by persons not involved directly in the treatments to minimize bias." p1000
 Comment: assessor was blinded
Incomplete outcome data (attrition bias) 
 All outcomes Low risk Comment: 8/74 (11%) dropouts
Selective reporting (reporting bias) Low risk Comment: all pre stated outcomes were reported
Other bias High risk Comment:

  • Trial was sponsored by third parties who were likely to have a vested interest in a positive finding

  • The unit of randomisation was the pressure ulcer and data were analysed by pressure ulcers with no account for non‐independence of data

ABPI: ankle‐brachial pressure index
 EPUAP: European Pressure Ulcers Advisory Panel
 ES: electrical stimulation
 EST: electrical stimulation therapy
 HVMPC: high voltage monophasic pulsed current
 HVPC: high voltage pulsed current
 IAET: International Association of Enterostomal Therapists
 IDC: interrupted direct current
 LIDC: low intensity direct current
 NPUAP: National Pressure Ulcers Advisory Panel
 PLIDC: pulsed low‐intensity direct current
 PSST: Pressure Sore Status Tool
 PWAT: Photographic Wound Assessment Tool
 SD: standard deviation
 SWC: standard wound care
 TENS: transcutaneous electrical nerve stimulation
 WSA: Wound Surface Area