Background: The results of the CLOTS 3 trial showed that intermittent pneumatic compression (IPC) reduced the risk of deep vein thrombosis and improved survival in immobile patients with stroke. IPC is now being widely used in stroke units. Here we describe the disability, living circumstances, quality of life, and hospital costs of patients in CLOTS 3.
Methods: In CLOTS 3, a parallel group trial in 94 UK hospitals, immobile patients with stroke from days 0 to 3 of admission were assigned with a computer-generated allocation sequence in a 1:1 ratio to IPC or no IPC through a central randomisation system. We followed up patients at about 6 months with postal or telephone questionnaire to assess the secondary endpoints: disability (Oxford Handicap Scale [OHS]), living circumstances, health-related quality of life (EQ5D-3L), and hospital costs (based on use of IPC and length of hospital stay). Patients and carers who completed the postal questionnaires were not masked to treatment allocation, but telephone follow-up in non-responders was masked. All analyses were by intention to treat. This trial is registered, number ISRCTN93529999.
Findings: Between Dec 8, 2008, and Sept 6, 2012, we enrolled 2876 patients, with 1438 in each group. Despite the previously reported reduction in the risk of proximal deep vein thrombosis at 30 days (primary endpoint), there were no significant differences in disability (OHS 0-2 vs 3-6, adjusted odds ratio [OR] 0·98, 95% CI 0·80 to 1·19, p=0·83; adjusted ordinal analysis common OR 0·97, 95% CI 0·86 to 1·11), living circumstances (institutional care vs not; adjusted OR 1·11, 95% CI 0·89 to 1·37; p=0·358), or health-related quality of life (median utility value 0·26, IQR -0·07 to 0·66 with IPC, and 0·27, -0·06 to 0·64, with no IPC; p=0·952). The estimated cost of IPC was £64·10 per patient (SD 28·3). The direct costs of preventing a deep vein thrombosis and death were £1282 (95% CI 785 to 3077) and £2756 (1346 to not estimable), respectively, with IPC. Hospital costs increased by £451 with IPC compared with no IPC because of a longer stay in hospital (mean 44·5 days [SD 37·6] vs 42·8 days [37·2]; mean difference 1·8 days, 95% CI -1·0 to 4·5). By 6 months, despite an increase in survival (IPC 152·5 days [SD 60·6] vs no IPC 148·1 days [64·3]; mean difference 4·5 days, 95% CI -0·2 to 9·1), there was a non-significant increase in quality-adjusted survival associated with IPC (IPC 27·6 days [SD 40·6] vs no IPC 26·7 days [39·6]; mean difference 0·9 days, 95% CI -2·1 to 3·9).
Interpretation: IPC is inexpensive, prevents deep vein thrombosis, improves survival but not functional outcomes, and does not lead to a significant gain in quality-adjusted survival. When deciding whether to treat patients with IPC, clinicians need to take into account all these potential effects.
Funding: National Institute of Health Research Health Technology Assessment Programme, Chief Scientist Office of Scottish Government, and Covidien.
Copyright © 2014 Dennis et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd. All rights reserved.