In the Green 1974 study the intervention was a lotion described as "active", containing hexachlorophane 0.5%, saturated hydrocarbons (squalene (Cosbiol 3%) and glyoxyle diureide), allantoin 0.2%, antioxidants, lanolin, fatty acids, fatty acid esters, fatty alcohols, preservatives and distilled water. For the control group, a lotion described as "inert" containing lanolin, fatty acids, fatty acid esters, fatty alcohols, preservatives, distilled water and mineral oils, was applied. The lotions were applied manually to pressure areas (sacral, trochanteric, heel and shoulder and other areas, as indicated). Excess friction was avoided. The participants' skin was inspected every two hours, and, if the participant was incontinent, the skin was washed with soap and water, then dried, and the relevant lotion applied. In the absence of incontinence, routine washing and reapplication of lotion was carried out every six hours.
In the Smith 1985 study the topical application for the intervention group was Conotrane, which contains silicone cream, 20% dimethicone 350 and a broad spectrum antiseptic (0.05% hydrargaphen). For the control group the topical application was described as a bland cream known as Unguentum. For both groups, as part of the routine skin care regimen, the skin of the participants was washed when required, with water, then dried thoroughly and the ointment applied.
In the Houwing 2008 study the topical application for the intervention group was massage using a “DMSO-cream.” The DMSO-cream consisted of 5% dimethyl sulfoxide in Vaseline-cetomacrogol cream; participants also had a 30o position change every six hours. For the placebo group the topical application was a three-minute massage of the buttock, heel, and ankle regions with an indifferent cream (Vaseline-cetomacrogol), combined with a 30o position change every six hours for four weeks. For the control group, no topical application was applied, but the participants had a 30o position change every six hours for four weeks.
In the Torra i Bou 2005 study the topical application for the intervention group was Mepentol, a hyperoxygenated fatty acid compound consisting of oleic acid, palmitic acid, stearic acid, palmitoleic acid, linoleic acid, gamma linoleic acid, arachidonic acid, and eicosenoic acid. For the control group, the topical application was a compound consisting of trisostearin (99.4%) and perfume (0.6%). In both groups, the topical application was applied twice daily to at least three areas of the body, sacrum, trochanter and heels.
Finally, in the Van Der Cammen 1987 study the topical application was Prevasore, which contains hexyl nicotinate, zinc stearate, isopropyl myristate, Dimethicone 350, cetrimide and glycol. For the control group the topical application was Dermalex which contains hexachlorophane, squalene and allantoin. In both groups, the participants' buttocks and sacral areas were washed and dried and the topical application was applied at least twice daily and again after changing, if the individual was wet or soiled.
In all of the studies using topical applications, no additional dressings were applied, the topical application was applied to the skin and the skin was then left bare.
In the Han 2011 study the intervention was a polyurethane film and foam dressing (Hang' huier transparent strip and foam dressing). This was applied to the pressure areas of the participants during surgery. The control group did not have any dressings applied.
In the Nakagami 2007 study, the intervention was a dressing, known as PPD (pressure ulcer preventive dressing). This consists of a skin adhesive layer (hydrocolloid) containing an intercellular lipid-ceramide, a support layer (urethane film) and an outer layer of multi-filament nylon fibres. The dressing was applied to either the right or left greater trochanter (depending on randomisation) of the participant. The dressing was replaced weekly. No dressing was applied in the control arm of the study.
In the Qiuli 2010 study the intervention was a soft silicone, self-adherent, bordered foam dressing applied to the integral skin site of pressed bone protuberance. The frequency of dressing changes was not mentioned in the paper. For the control group, massage of the site of bone protuberance was undertaken at each patient-turning episode (two- to three-hourly). The duration of massage was not mentioned in the paper. Both groups were nursed on air cushion mattresses and repositioned every two to three hours.
In the final study of Kalowes 2012, the intervention was a soft silicone, self-adherent, bordered foam dressing applied to the subjects' sacrum. The dressing was changed every three days, or as needed. No dressing was applied to the skin of the control group participants. Both groups were nursed according to the SKIN bundle (Surface, Keep turning, Incontinence and Nutrition) (Gibbons 2006).
All the studies included the development of a pressure ulcer as their primary outcome.Two used the validated scale of EPUAP 1999 (Houwing 2008; Nakagami 2007). Han 2011 reported use of an international measurement for pressure ulcers titled “WCET”; Green 1974 used a five-point scale; Smith 1985 used the classification of Barbarel 1977; while Van Der Cammen 1987 used a five-point scale; finally, Torra i Bou 2005, Qiuli 2010 and Kalowes 2012 did not identify the classification system used.
Ethics and consent
No information about ethics approval or participant consent was provided by Green 1974, Han 2011, Kalowes 2012, Qiuli 2010 or Van Der Cammen 1987. Although Smith 1985 had ethics approval, it was not reported whether participants consented. Information on ethics and consent for the remaining studies was not available (Houwing 2008; Nakagami 2007; Torra i Bou 2005).
Seven of the nine trials reported receiving support from the manufacturers of the interventional product (Green 1974; Han 2011; Kalowes 2012; Nakagami 2007; Smith 1985; Torra i Bou 2005; Van Der Cammen 1987). Sponsorship for the Houwing 2008 study came from ZonMw (Ministry of Health, Welfare and Sport and the Netherlands Organisation for Scientific Research). Qiuli 2010 did not state whether sponsorship was received. In the Nakagami 2007 trial, investigators were involved in developing the dressing used in the study. The corresponding author in the Van Der Cammen 1987 trial was an employee of the company producing the intervention product.