The effectiveness and safety of heat/cold therapy in adults with lymphoedema: systematic review.

Almost all the studies measured people before and after treatment without a control group, so the reviewers cannot tell whether the swelling improved because of the heat or cold, because of the other treatments given at the same time, or on its own. Only two before-and-after studies, three non-randomised controlled studies and one randomised trial were judged at low risk of bias, and the reviewers note that poor reporting made many studies hard to judge. Because the studies were so different, the reviewers counted how many reported improvement instead of pooling the results. This gives no estimate of how much improvement to expect, takes no account of how big or how good each study was, and cannot assess inconsistency, imprecision or publication bias. No outcome was required for inclusion, so studies measured different things and the reviewers could not compare them directly. Screening of titles and abstracts was done by one reviewer, and full-paper screening, data extraction and quality assessment were done by one reviewer and only checked by a second rather than independently. Three papers could not be obtained at all. The search was run on 22 March 2023 and only three relevant papers were published in the decade before it, so the review will date. Most studies took place in hospitals, laboratories or outpatient clinics with controlled temperatures and long supervised treatment periods, so it is unclear whether any benefit would carry over to self-management at home. Most studies looked at lymphoedema of the legs, so there is less certainty about the arms and less still about cold therapy.

The review was funded by the National Institute for Health and Care Research Applied Research Collaboration North West Coast, with additional funding from the University MedTech Solutions Group. No conflicts of interest are stated in the text provided. Neither funder is described as having designed the review or written it up.

Do not read the improvements in limb circumference and limb volume as proof that heat therapy works for lymphoedema. Almost all of the studies measured people before and after treatment with no control group, so the swelling could have improved for other reasons or because of the other treatments given at the same time, and the reviewers themselves conclude that no recommendation for practice can be made.