Hand Hygiene Studies Awash in Flawed Data

LONDON, April 18 -- It's not easy to find clean studies on how to improve hand hygiene, reported investigators here after a literature search.

In a systematic review, Cochrane Collaboration investigators discarded 48 studies on hand hygiene as poorly controlled before settling on only two that were sufficiently reliable to include. One found an approach that would improve hand hygiene. The other evaluated a study that did not help.

There has been a considerable increase in the number of studies looking at various tactics to improve hygiene, but "the evidence base remains poor," according to Dinah Gould, Ph.D., of City University's School of Nursing and Midwifery.

The two studies were randomized controlled trials from China (Huang et al. in 2002) and a controlled before-and-after study from London (led by Dr. Gould in 1997). Both evaluated a single intervention involving education relating to universal precautions as well as hand hygiene.

In the Chinese study, the researchers randomized 100 nurses to experimental and controls groups. The experimental group was given two hours of formal teaching about blood borne pathogens and universal precautions, an hour of practical demonstration, 30 minutes of discussion, and written information.

The researchers collected data on the nurses' hand-washing by direct observation before the intervention and again four months later. The study found that the intervention significantly improved (at P<0.001) hand-washing among the nurses in the experimental group compared to controls.

In the British study by Gould et al., the researchers selected two surgical units to act as the experimental group and matched them with two control units. Nurses on the experimental units were given five different half-hour sessions, covering infection control generally and universal precautions and hand hygiene specifically, along with practical demonstrations.

Each nurse was observed continuously for two hours by the same observer, who was blinded to group allocation, and the outcome measure was the number of "essential" hand washes performed after activities judged likely to offer a risk of cross-infection.

Three months post-intervention the number of essential hand washes was similar in the intervention and control groups, the researchers found.

While the two studies do not form a solid footing on which infection control experts can base a choice of hygiene interventions, the chief conclusion is that "soundly designed studies are urgently required," Dr. Gould and colleagues wrote.

"We desperately need some good research that will begin to show which interventions can bring about change in people's behavior that will lead to increased hand hygiene," Dr. Gould said.

"In addition to preventing unnecessary spread of disease, good hand hygiene is highly desirable on aesthetic grounds alone, it forms an important indicator of the quality of health care and should continue to be promoted in all clinical settings," she said.