3 Clinical evidence

3 Clinical evidence

Summary of clinical evidence

3.1 Full details of all clinical outcomes considered by the committee are available in the assessment report overview.

3.2 The key clinical outcomes for Parafricta Bootees and Undergarments presented in the decision problem were:

  • incidence and severity of pressure ulcers or skin breakdown

  • length of hospital stay

  • time to healing for those with an existing pressure ulcer

  • compliance with pressure ulcer management

  • the person's comfort (including ability to move and self‑reposition in bed)

  • quality of life

  • device‑related adverse events.

3.3 The clinical evidence for Parafricta Bootees and Undergarments presented by the sponsor was 4 published multiple‑patient case‑series reports, 3 of which were peer‑reviewed papers (1 with historical controls) and 1 poster. These were Hampton et al. (2009), Loehne (2013; poster), Smith and Ingram (2010; with historical controls) and Stephen‑Haynes and Callaghan (2011). The sponsor also identified 3 single case studies but these were not presented. Independent searches by the external assessment centre (EAC) found no additional relevant studies. Data from an unpublished audit (Gleeson 2014) were sent to the EAC by the sponsor during the evaluation.

Multiple‑patient case series: peer‑reviewed papers

3.4 A case series of 25 nursing home residents by Hampton et al. (2009) evaluated whether using a Parafricta Bootee or Undergarment could reduce oedema and inflammation associated with pressure ulcers. All residents had restricted mobility and each had redness and a 'boggy' feel to the tissues, either over the sacrum or 1 or 2 heels. A total of 28 pressure ulcers of grade 1 or above were analysed, all of which were related to friction or shear. Ten people used a Parafricta Bootee on the right heel (the left heel [control] without the Bootee was used as a comparator) and 18 used a Parafricta Undergarment ('normal' skin adjacent to the sacrum was used as a comparator). The degree of oedema and inflammation of the pressure ulcers was measured using 3 methods: high‑frequency ultrasound scan data, colour photographs and tissue assessment by a tissue viability nurse. Statistical analysis of the high‑frequency ultrasound data was conducted using the Kolmogorov–Smirnov 2‑sample test. For this analysis, the skin profile of each heel (treated and control) was compared with a 'normal' heel profile (a standard heel with no pressure ulcer or redness). At the start of the study, results showed that both the treated heel (p<0.001) and the control heel (p<0.001) were statistically significantly different from the normal heel. At the end of 4 weeks, the difference between the treated heel and the 'normal' heel had reduced (p=0.2), whereas the difference between the control heel and the 'normal' heel was still statistically significant (p<0.001). Analysis of the treated heel results at week 0 compared with week 4 showed an improvement with a statistically significant difference (p<0.001). Based on these results, the authors concluded that the heel treated with a Parafricta Bootee became more similar to the 'normal' heel, and that Parafricta garments were effective in reducing oedema. The tissue viability nurse assessment found that bogginess and redness were reduced in the treated heels of all 10 residents but there was no change in the control heels. Results from the analysis of the high‑frequency ultrasound data for the sacral area showed a statistically significant difference between baseline and week 4 (p=0.006). Bogginess and redness were reduced in all 18 residents treated with a Parafricta Undergarment. The colour photographs for both the heels and the sacral areas were not considered clear enough by the researchers to validate the results. The ultrasound data were deemed to be more objective and reliable than either the colour photographs or the visual assessment.

3.5 The case series by Loehne (2013; poster) evaluated the use of Parafricta Bootees to prevent pressure ulcers in nursing home residents who were at risk of developing heel pressure ulcers as a result of friction and shear. Although the poster did not report how many residents were involved, the sponsor submission stated that the study included 6 residents and the intervention was a standard pressure‑reducing surface plus a Parafricta Bootee. After 30 days, none of the residents had developed a pressure ulcer or had any healed ulcers recurring. This included 1 person who had had a recurrent pressure ulcer for 2 years.

3.6 Smith and Ingram (2010) investigated the effectiveness of Parafricta garments in reducing the incidence and prevalence of pressure ulcers in hospital. The study incidence data were collected from 2 medical wards and 1 orthopaedic ward over 6 consecutive months. The first 3 months provided the data for group 1 (n=204) and the next 3 months were used for group 2 (n=165). People in both groups had identical care using the hospital's standard pressure ulcer prevention protocol, except that those in group 2 were also given a Parafricta Bootee or Undergarment. It was not clear how many had a Bootee or an Undergarment or both. Analysis of Waterlow scores suggested that they did not differ between the 2 groups. The authors reported the results as percentage differences in incidence of pressure ulcers between the groups. For additional ease of interpretation, the EAC recalculated the results as relative risks. The results showed that at‑risk people who were admitted to hospital without a pressure ulcer were more likely to develop a pressure ulcer in the no Parafricta group than in the Parafricta group (relative risk [RR] 1.64, 95% confidence interval [CI] 1.05 to 2.59). For at‑risk people admitted without a pressure ulcer who then developed one, those in the no Parafricta group were more likely to have an ulcer that deteriorated or did not improve compared with those in the Parafricta group (RR 2.53, 95% CI 1.16 to 5.52). A similar result was found for people who were admitted with an existing pressure ulcer: risk of deterioration was more likely in the no Parafricta group than in the Parafricta group (RR 4.90, 95% CI 1.75 to 13.75). There was no statistically significant difference between the groups in the risk of developing an additional ulcer in people who were admitted with one (RR 1.55, 95% CI 0.87 to 2.75). The Smith and Ingram (2010) study reported median lengths of stay. The EAC obtained the study data from the sponsor and reanalysed it to calculate mean lengths of stay for each group as a more appropriate parameter for use in the economic model. The average length of stay was calculated by weighting the length of stay in each treatment group by the proportion of people in the group. Results showed a weighted mean length of stay of 20.31 days for the no Parafricta group and 16.27 days for the Parafricta group, a statistically significant difference of 4.05 days (p=0.019). The EAC also used the limited information on confounding factors to estimate adjusted length of stay values, which took into account reported baseline characteristics between the groups. Results showed a weighted mean length of stay of 14.94 days for the no Parafricta group and 12.47 days for the Parafricta group, a difference of 2.47 days. No demographic characteristics were reported for either group.

3.7 Stephen‑Haynes and Callaghan (2011) described a case series of 25 nursing home residents who used Parafricta Bootees and Undergarments in addition to the standard approach for ulcer prevention and management as outlined in NICE's guideline on pressure ulcers. At the start of the study, 20 residents had an existing pressure ulcer of category 2 or below and 5 had intact skin. Those with intact skin were considered at risk of developing a pressure ulcer through friction due to repetitive movements caused by their medical condition. The outcomes that were considered included skin improvement, ease of use, garment retention and patient comfort. No information about the timescale of the study was provided. There was skin improvement in 76% (n=19) of residents, whereas 24% (n=6) remained the same. Clinicians found the garments very easy to use for most people (64%, n=16), and 88% (n=22) of clinicians stated that Parafricta garments had a positive impact on clinical outcomes. All residents in the study found the garment comfortable (24%, n=6) or very comfortable (76%, n=19). Almost half (48%; n=12) of clinicians reported that it was very easy to keep the garments in place, and 16% (n=4) did not find it easy. This was an uncontrolled study so it was difficult to tell whether any improvement in pressure ulceration or skin improvement was temporary or prolonged, or even whether any improvement was because of Parafricta garments.

Summary of results from the unpublished audit

3.8 The unpublished clinical audit by Gleeson (2014) evaluated the use of Parafricta Bootees in people at high risk of pressure ulcers on 6 hospital wards in the St. Helen's and Knowsley Teaching Hospitals NHS Trust over a 12‑month period (January to December 2012). The author reported a 32% reduction in hospital‑acquired grade 2 pressure ulcers compared with the previous year. Other details were made available to the committee on an academic‑in‑confidence basis and the author supplied additional academic‑in‑confidence information during the consultation, although details cannot be reported here. The EAC considered it unclear how much of the reduction in pressure ulcers reported was because of the use of Parafricta Bootees, and how much was caused by other pressure ulcer prevention initiatives taking place at the NHS trust.

Adverse events

3.9 The sponsor found no adverse event reports relating to Parafricta garments. No alerts have been issued, and no information was found in a search of the Medicines and Healthcare products Regulatory Agency website.

Committee considerations

3.10 The committee noted that the clinical evidence base for Parafricta garments was 4 published multiple‑patient case series and 1 unpublished audit. The committee agreed with the EAC's conclusions that there was a lack of good quality comparative evidence against standard care. The committee recognised that there is often only limited evidence for products used in pressure ulcer prevention and management , but considered it possible to conduct comparative research of good quality to assess the clinical effectiveness of this technology.

3.11 The committee accepted the EAC's critique of the Smith and Ingram (2010) study and agreed that because of potential confounding factors, it is not clear that any change in the pressure ulcer incidence or severity was due to Parafricta garments. The committee also agreed with the concerns raised by the EAC about the unpublished Gleeson audit (2014), including the additional data submitted during consultation, and it was not convinced that the reduction in heel pressure ulcers documented in the audit was solely because of the Parafricta Bootees.

3.12 Based on the existing evidence base and expert advice, the committee considered that Parafricta garments may indeed reduce pressure ulcer incidence and severity, and so provide potential benefits for patients. The committee was aware that older people and those with frail skin are more susceptible to pressure ulcers as a result of friction or shear, and it considered that Parafricta garments may be particularly beneficial to these people. However, it judged that the case for routine adoption in the NHS could not currently be supported because there are too many uncertainties in the evidence base.

3.13 The committee wished to encourage comparative research in hospitals (for ease and speed of generating findings) to investigate the clinical effectiveness of Parafricta garments as an adjunct to standard care compared with standard care alone in reducing skin breakdown in people with or at risk of pressure ulcers. The study should be randomised and the assessors blinded to minimise bias in the results. The committee specified that the research should focus on determining relative effectiveness compared with standard care when biases were carefully controlled for, and on developing criteria to identify patients for whom Parafricta garments are most likely to be effective.

3.14 The committee recognised that there is great potential for the use of Parafricta garments in the community. It considered that they could be beneficial to patients with long‑term conditions where pressure ulcers are a significant problem. However, it was advised of the significant challenges of conducting comparative research in the community. The committee considered that the results obtained in hospitals could plausibly be generalisable , and advised that the need for the findings from a hospital setting to be generalised to community‑based settings should be factored into the design of the research studies.

3.15 The committee discussed outcomes of special importance to patients. It noted the results from the Stephen‑Haynes and Callaghan (2011) case series which suggested that the garments were easy to use and that patients found them comfortable. Expert advice to the committee was that the fastenings ensure the garments remain in place, and that they have proven popular with patients. No adverse events were identified as a result of their use. The committee concluded that Parafricta Bootees and Undergarments are convenient, easy to use and well tolerated by patients, but considered that a record of patient experience would be useful to incorporate in future research studies.

3.16 For the guidance review, the EAC reviewed evidence published since November 2014. There were 3 publications of 2 single-arm studies on the technology. No new evidence compared Parafricta bootees or undergarments with standard care. In 1 study heel ulcer incidence reduced by 84% after Parafricta bootees were introduced. This was across all wards in 2 hospitals over 5 years of follow up (Gleeson 2015 and 2016). Another study reported on 15 people who used the Parafricta bootees. It reported a significant reduction in peak pressure on heels and other areas of the feet in direct contact with a surface. People rated the technology as 'excellent' or 'good' (Schofield 2018). The EAC considered that the new evidence did not answer the uncertainties that led to the recommendation for research in this guidance. [2021]

  • National Institute for Health and Care Excellence (NICE)