Does acupressure help reduce nausea and vomiting in palliative care patients?

Nausea and vomiting are common symptoms of patients with advanced cancer. While there is some evidence for acupuncture point stimulation in the treatment of these symptoms for patients having anticancer treatment, there is little for when they are not related to such treatment.

This study aimed to determine whether acupressure at the pericardium 6 sites can help treat nausea and vomiting suffered by palliative care patients with advanced cancer. The researchers conducted a double-blind randomized controlled trial-active versus placebo acupressure wristbands. In-patients with advanced cancer in two specialist palliative care units who fitted either or both of the following criteria were approached: nausea that was at least of moderate severity; vomiting daily on average for the prior 3 days.

A total of 57 patients were randomized to have either active or placebo acupressure wristbands. There was no difference in any of the outcome measures between the two groups:

• change from the baseline number of vomits;
• Visual Analogue Scale for ‘did acupressure wristbands help you to feel better?’;
• the total number of doses of antiemetic medication;
• the need for escalation of antiemetics.

The authors concluded that, in contrast to a previously published feasibility study, active acupressure wristbands were no better than placebo for specialist palliative care in patients with advanced cancer and nausea and vomiting.

When the research into acupuncture for nausea and vomiting began some 20 years ago, the evidence turned out to be encouraging. Later, as the studies became more and more rigorous, many trials failed to confirm the initial findings. Today, the totality of the evidence is far less convincing than it seemed years ago.

This is a phenomenon that can be observed not just in acupuncture research but in many types of treatment:

• Initially, over-enthusiastic researchers become victims of their own optimism.
• These investigators are less into testing hypotheses than into confirming their own wishful thinking.
• Thus, several positive trials emerge.
• These, however, turn out to be methodologically flawed.
• Eventually, the subject might be picked up by real scientists who truly test hypotheses.
• More and more negative studies thus emerge.
• Depending on how many flawed studies were initially published and how critical the authors of systematic reviews are, it can take years until the totality of the evidence depicts the true picture which discloses the initial findings as false-positive.

The message is, I think, clear: poor quality studies have the potential to mislead us for many years. Eventually, however, the self-cleansing ability of science should generate the truth about the value of any treatment. In other words:

poor-quality science is not just useless, it causes long-term harm

and

critical thinking prevents harm