Date of Award


Document type


Degree Name

PhD (Doctor of Philosophy)

First Supervisor

Professor Seamus Cowman


pressure ulcer, aged, randomised controlled trial


Background: International best practice advocates the use of repositioning for the prevention of pressure ulcers; however, there is confusion surrounding the best method and frequency required. Therefore, a pragmatic, multi-centre, open label, prospective, cluster randomised controlled trial of repositioning for the prevention of pressure ulcers was undertaken.

Aims: The aims of the study were to; compare the incidence of pressure ulcers among older persons in long-term care hospitals, nursed using two different repositioning regimes; identify pressure ulcer prevalence among older persons in long-term care, and to compare the cost implications of repositioning individuals using two different repositioning regimes.

Methods: Ethical approval was received. Study sites (n=12) were randomly selected. Allocation to study groups was by cluster randomisation using remote randomisation. The experimental group (n=99) were repositioned 3-hourly at night, using the 30 degree tilt; the control group (n=114) received routine prevention. Data analysis was by intention-to-treat; follow up was for 4 weeks. For the prevalence study, participants comprised 1,100 older persons residing in the study settings. Data were collected using the Braden scale, the EPUAP minimum data set and the EPUAP pressure ulcer grading system. For the cost analysis, the focus was on the cost difference between the two study groups (in terms of the number of nurses needed per turn, the time per turn, the cost of a nurse per minute and the cost of dressing treatments and nurse time for dressing changes for pressure ulcers that developed during the study period).

Results 1: For the prevalence study, all participants (n=1,100) were Irish Caucasian, 70% were female, and 75% were aged 80 years or older. Prevalence was 9%; 28% of pressure ulcers were grade 1, 33% grade 2, 15% grade 3 and 24% grade 4. The most common locations for pressure ulcers were the sacrum (58%) and the heel (25%). Seventy seven percent scored Braden low risk or not at risk, however, 53% were completely immobile/very limited mobility and 58% were chair/bedfast. There was a significant association between activity and mobility and pressure ulcer development (X2 45.50, p≤.0001 and X2 46.91, p≤.0001 respectively). Conversely, no association was found between nutrition and incontinence and pressure ulcer development (X2 15.96, p=.193 and X2 11.27, p=.506 respectively). Fifty percent had a pressure redistribution device in bed and 48% had one in use on the chair; although only 9% had a repositioning regimen planned for when in bed, and only 5% planned for when seated in the chair.

Results 2: For the randomised controlled trial, all participants (n=213) were Irish Caucasian; 77% were female, and 65% were aged 80 years or older. Routine prevention for the control group was identified as turning during the night, on average, every six hours, using 90 degree lateral rotation. Three patients (3%) developed a pressure ulcer in the experimental group (3-hourly turning), whereas 13 patients (11%) developed a pressure ulcer in the control group (6-hourly turning), this difference was statistically significant (X2 5.347, p=.021). All pressure ulcers were grade 1 (44%) or grade 2 (56%).

Results 3: For the economic analysis, the mean time-per-turn was 3.01 minutes (experimental), and 5.93 minutes (control). The mean number of nurses needed for each turn was 1.51 (experimental), and 2.02 nurses (control). The mean daily nurse time was 18.5 minutes (experimental) and 24.5 minutes (control) (p≤.0001). The daily mean difference between the groups was -6.00 minutes (95% CI -3.71 to -8.48). The cost per patient was €207.4 (experimental) and €274.3 (control) (p≤.0001). The mean difference between the groups is -€66.90 (95% CI –€24.68 to –€81.03). In the experimental group, 96.6% of participants remained free of pressure ulcers, 88.1% of patients remained pressure ulcer free in the control group (p=0.030). The incremental cost effectiveness ratio is -€787, thus the intervention is a dominant option (costs are lower for better outcomes). For the total study period, the cost of repositioning was €19,958.40 (experimental) and €31,270.20 (control). Total pressure ulcer dressing treatment was €3.87 (experimental) and €100.36 (control). Total costs were €19,962.27 (experimental) and €31,370.56 (control). The cost difference between the two positioning regimens was -€11,408.29. Projected annual costs of repositioning were estimated for those who would require repositioning of all individuals who where hospitalised across the study sites, using the 30 degree tilt compared to repositioning using standard care. Of these individuals, 53.5% would require repositioning based on Braden mobility scores. Costs for use of the 30 degree tilt were estimated as €258,402.48, these costs were estimated as €509,078.64 for standard care. The annual cost difference is -€250,676.16.

Conclusion: This study reports on a ‘low-technological’ intervention that has shown to have a direct effect on pressure ulcer incidence. Repositioning older persons at risk of pressure ulcers every three hours at night, using the 30 degree tilt, reduces the incidence of pressure ulcers when compared to usual care. It is also less time consuming, requires less personnel and is more cost effective when compared with standard care. The study also reports on the first ever pressure ulcer prevalence survey conducted in long-term care in Ireland and results provide significant insights into decision-making and use of resources in the prevention of pressure ulcers.

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Submitted for the Award of Doctor of Philosophy (PhD) to the Royal College of Surgeons in Ireland, 2009.