Criticisms of the Evidence

The research base in complementary medicine is small and often poor quality, partly because of a lack of funding and research skills in the field.

Critics of complementary medicine believe there's little or no scientific evidence to support the therapies' treatment claims. They believe the reported benefits are due to a placebo effect and the therapies should be tested against placebo (dummy) treatments to see if they're effective.

The Placebo Effect

It's difficult to design suitable placebos for many complementary therapies - how do you give a dummy massage, for example? But placebos aren't possible for many conventional treatments either. Much of what surgeons and physiotherapists do can't be tested in a placebo-controlled trial, for example.

Also, the placebo effect is poorly understood and the literature on it is confusing. Some thoughts about what may lie behind the placebo effect include:

• Spontaneous resolution of the condition (with or without treatment)

• A learned response (if the patient has experienced pain relief in the past after taking a white pill, for example)

• Expectation the treatment will work

Randomised Trials

Many people believe complementary therapies should be tested with randomised controlled trials, considered the 'gold standard' by researchers assessing conventional drugs.

Participants are randomly assigned to two (or more) similar groups, one receiving the treatment and the other receiving an alternative treatment, placebo or no intervention.

There are two types of randomised controlled trial:

• Explanatory trials are carried out in controlled conditions and rely on patients to keep closely to the design conditions of the trial

• Pragmatic trials allow for the individual tailoring of a treatment to a patient, by comparing packages of treatment

Two other types of study may help measure a treatment's effectiveness:

• Systematic review - an overview of primary studies (usually controlled trials)

• Meta-analysis - the pooling of results of primary studies

If the primary studies and the meta-analysis are of a high standard, the results of such studies can provide a high standard of evidence.

Safety and Integrated Healthcare

If you're planning to see a complementary practitioner because you're unwell, it's a good idea to consult your GP first. They can rule out any dangerous or life-threatening cause and discuss treatment options with you.

It's important your complementary practitioner is aware of any diagnosed medical conditions you have, and any prescribed or over-the-counter medicines you're taking.

You should tell your GP and pharmacist about any complementary treatments you're using, too. Don't forget to mention products or supplements you've bought for yourself, and never change or stop taking a prescribed medicine without talking to your GP first.

Different treatments can affect each other, making them less effective or causing unpleasant or dangerous effects. This is particularly important to remember when taking herbal remedies, as some interact with prescription medicines, such as St John's wort and oral contraceptives.

Source: BBC/Health