This is a plain English summary of an original research article
People having surgery prefer wearing knee length to thigh length compression stockings to prevent deep vein thrombosis (DVT). They are more likely to wear knee length stockings correctly and for the recommended time.
DVT is a clot in the deep leg veins and surgery is a known risk factor. If the clot travels to the lung blood vessels, this can cause the potentially fatal complication of pulmonary embolism.
This review of 16 studies included randomised trials and observational studies reporting adherence and acceptability, but these were dated and had an unclear risk of bias. No conclusions can be made about use with specific types of surgery. The studies did not assess whether patients continue to use stockings after hospital discharge.
Adequate patient information, careful fitting, support and follow-up may influence whether people use compression stockings correctly.
Why was this study needed?
It has been estimated that 25,000 patients die in the UK each year because of a venous blood clot that developed in hospital. Prolonged immobility and major surgery, particularly of the hip, legs or abdomen, are known to increase the risk of developing DVT. Previous research has suggested nearly three-quarters of people at risk haven’t used mechanical or drug treatments to prevent clots.
Compression stockings help to prevent blood pooling and clotting in the leg veins. There is some evidence that thigh length stockings are more effective than knee length stockings but patients may find them less comfortable and thus not wear them as reliably. Patients need to wear stockings correctly and for the length of time recommended. Incorrect use can lead to problems such as skin or nerve damage and reduced blood flow.
A person’s preference for one stocking length over another may affect whether they use them properly and get the full benefit.
What did this study do?
This NIHR funded systematic review found nine randomised controlled trials and seven observational studies assessing preference and/or adherence to wearing knee length or thigh length compression stockings for a total 4,188 patients undergoing day-case or inpatient surgery.
As this narrative review of studies reported preference and adherence it is not possible to say how well either stocking worked. There were also some limitations to the approach and the age of the underlying studies. These mean that the estimates of adherence should be treated with caution. For example, studies varied widely in how they measured adherence, this can make it hard to interpret and apply the results. Unfortunately half of the studies were more than 20 years old and may not have included the range of current stockings now available. It is possible adherence is now better. The principles of considering comfort and expert fitting are likely to still apply.
What did it find?
- Two trials and four observational studies reported patients’ preference for thigh or knee length stockings: the majority of patients preferred knee length. Patients generally reported that knee length stockings were more comfortable.
- Six observational studies reported patients’ adherence to thigh or knee length stockings. Adherence to any stocking was generally quite poor. However, the proportion not wearing their stockings, or wearing them incorrectly, was generally higher in patients given thigh length ones. For example, one study found 17% of people prescribed thigh length stockings never used them, compared with 3% for knee length. Another found 54% wore thigh length stockings incorrectly compared with 20% for knee length. All evidence on adherence was limited to wear in the hospital setting when supervised by health professionals.
- Reasons for discontinued use of stockings included discomfort, taking them off for bathing, or the patient thinking they were no longer needed as they’d started to walk around. Reports of incorrect use included wearing stockings of the wrong size or rolling them down the leg. Instances of both non-use and incorrect use tended to be greater with thigh length stockings than knee length.
What does current guidance say on this issue?
The NICE guideline on reducing the risk of venous thromboembolism (VTE) for patients in hospital recommends starting treatment to prevent blood clots as soon as patients are admitted to hospital. It suggests various ways of doing this, including using compression stockings where appropriate. Knee or thigh length stockings can be used, and these should be fitted properly. It also says that patients should be given information on how to use stockings correctly, both during their hospital stay and once they go home, if necessary.
What are the implications?
If patients find knee length stockings more comfortable they are more likely to wear them correctly and for the recommended length of time, potentially increasing their effectiveness over thigh length stockings. This conclusion must be interpreted in the context of relatively old evidence that looked at adherence to a range of stockings applied in hospitals.
Nevertheless the findings suggest that surgical patients’ preference for knee or thigh length stockings should be taken into account when prescribing.
It is important that patients are fully informed on the need for preventative treatment for DVT, and that they receive the necessary take-home advice and follow-up upon hospital discharge.
Citation and Funding
Wade R, Paton F, Woolacott N. Systematic review of patient preference and adherence to the correct use of graduated compression stockings to prevent deep vein thrombosis in surgical patients. J Adv Nurs. 2016. [Epub ahead of print].
This project was funded by the National Institute for Health Research HTA Programme (project number HTA 13/72/01).
NHS Choices. Preventing deep vein thrombosis. London: Department of Health; 2016.
NICE. Venous thromboembolism: reducing the risk for patients in hospital. CG92. London: National Institute for Health and Care Excellence; 2015.
Wade R, Sideris E, Paton F, et al. Graduated compression stockings for the prevention of deep vein thrombosis in postoperative surgical patients: a systematic review and economic model with a value of information analysis. Health Technology Assessment. 2015;19(98);1–220.
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