Searching the literature

Steve Simon


[StATS]: Searching the literature (May 3, 2005)

Next week, our hospital will have a seminar on Reiki. I thought it would be useful to see what evidence there was on this technique. My search included access to several resources through a system called Ovid. Unfortunately, Ovid requires a fee, so it is not available to the general public. There are free sources of information, but these are scattered around and provide less comprehensive coverage than Ovid. For example, the site offers you the abstracts, but not the full text of the Cochrane Database of Systematic Reviews.

My search was a bit ill focused, unfortunately. Normally, when you do a search, you specify four things:

but since I am just curious about Reiki in general, I only have the I part of PICO defined. It would be better to ask a question like:

In adults with lower back pain (P), does the use of Reiki therapy (I) compared to physical massage (C) affect the patient’s self report of pain?

There are several good guides to the PICO format:

It’s a good idea to start at the highest level of the evidence hierarchy and work your way down. So I went first to the Cochrane Database of Systematic Reviews and looked for any review including the word “Reiki.”

There were five reviews, but none of these looked helpful. Two of them used Reiki as an exclusion criteria and the other three allowed Reiki as a cointervention but did not evaluate its effects.

Then I went to an Ovid link to “All EBM Reviews - Cochrane DSR, ACP Journal Club, DARE, and CCTR.” A search here yielded 16 links including the five I had found earlier.

Several results looked promising:

The first two are critical reviews of a paper:

that looks at several therapies including Reiki. You can get a pdf version of this paper but when you read this paper, it turns out that none of the papers selected for this systematic review incorporated the practice of Reiki.

All of the remaining links refer to single trials, so I put them on hold for now to see if I could something broader instead.

A peek at the National Guideline Clearinghouse (free to the public at yielded no hits on “Reiki.” I did not hold out a lot of hope here, because this is a resource better suited when you have a well defined patient population that you need to manage. Since I am totally missing the P portion of PICO, I am at a serious disadvantage here.

A review of the Best Bets website ( -- please don’t put a .com here because it will lead to a gambling site), also yielded no publications relating to Reiki.

Then I went to PubMed. A search for “Reiki” with a limit of publication type to meta-analysis yielded two publications, both of which focused on therapeutic touch rather than Reiki.

A search without limits yielded 381 articles, too many to skim through.

It may be time to think about single randomized trials again, so I reran the “Reiki” search with publication type of randomized clinical trials. This yielded 28 references, most of which talked about therapeutic touch rather than Reiki.

I was curious why I was getting so many articles about therapeutic touch. It turns out that Medline apparently lumps Reiki in with therapeutic touch as a MeSH term. To look for references that use the word “Reiki” rather than the MeSH term associated with Reiki, you need to use [tw], the text word tag.

If you do a search on “Reiki [tw]” without any limits, you get 52 articles rather than 381. Now restrict this list to publication type of randomized controlled trial, and you get six references. Most of these are articles that we found earlier.

So what did I learn? There may be a few good systematic reviews out there, though they seem to focus on therapeutic touch rather than Reiki. There are a handful of randomized trials out there that mention Reiki directly instead of therapeutic touch. I have not had time to critically appraise any of these articles.

Postscript (May 4, 2005): I asked for some comments and suggestions from the Evidence Based Health mailgroup, and got two responses right away. One person pointed out an evidence based review

You can also browse for pages similar to this one at Category: Information searching.

You can find an earlier version of this page on my website.