According to the Research Trisha E. O’Hehir, RDH, BS
Editorial Director, Hygienetown Magazine

“Evidence-Based Health Care” is now a familiar concept, but it wasn’t always that way. The evidence-based approach began with Dr. Archibald Cochrane (1909-1988), a Scottish medical researcher who contributed greatly to the development of epidemiology as a science. From the stories in his book entitled, “Effectiveness and Efficiency,” he definitely sounds like an interesting fellow.

Dr. Cochrane’s early experience came from four years as a German prisoner of war (POWs). He was put to work as the doctor for about 20,000 POWs in the first camp, a quarter of the POW camp population was British. The men had a diet of about 600 calories a day. Diarrhea, severe epidemics of typhoid, diphtheria, infections, jaundice, and sand-fly fever were rampant. All Dr. Cochrane had to offer as care were a ramshackle hospital, some aspirin, antacid, and skin antiseptic. In the absence of specific therapy, he expected hundreds to die of diphtheria. Surprisingly, there were only four deaths––three due to gunshot wounds inflicted by the Germans! This excellent result had, of course, nothing to do with the medical care provided or his clinical skills as a doctor, but it clearly demonstrated the relative unimportance of therapy compared to the recuperative power of the human body.

As the only physician caring for these men, he asked the German in charge for more doctors to help him cope with the fantastic problems. His request was denied with the response, “doctors are superfluous!” Of course Dr. Cochrane was furious at this response, but later came to realize it was correct.

He was later transferred to another POW camp where he cared for many soldiers with tuberculosis. Conditions were better at this facility than the first camp as he had access to testing, medications and even surgery. The men also received adequate food and were allowed to rest. Despite being in a POW camp, the good doctor had considerable freedom in therapy options. The trouble was, he didn’t know which therapy to use or when. He had no real evidence that anything available had any effect on tuberculosis, and was afraid he might actually shorten the lives of some men by unnecessary intervention.

Returning to Britain, Dr. Cochrane was frustrated with a lack of evidence to support medical treatments of his day. He spoke and wrote of the importance of systematically reviewing randomized controlled trials. Cochrane’s simple propositions were soon widely recognized and valued by lay people as well as health professionals. At that time, it was a matter of life and death. Some interventions and therapies appeared to treat the problem, but actually resulted in increased patient death. Doctors needed to know which treatments were both effective against specific problems, yet were free from serious side effects such as death.

In 1979 he wrote, “It is surely a great criticism of our profession (medical) that we have not organized a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomized controlled trials.” His challenge led to the establishment of an international collaboration to develop the Oxford Database of Peri-Natal Trials.

In 1987, the year before Cochrane died, he called the review of clinical trials of care during pregnancy and childbirth “a real milestone in the history of randomized trials and in the evaluation of care,” and suggested that other specialties should copy the methods used.

The Cochrane Collaboration, an evidence-based health research organization named in honor of Dr. Cochrane, opened in Oxford, Britain in 1992. Since then, many medical reviews have been carried out, following the mission of the collaboration to “prepare, maintain and promote the accessibility of systematic reviews of the effects of health care interventions.” In addition to medical reviews, oral health reviews are being added each year.

Scientific evidence is only one part of the equation. Clinicians must bear the responsibility of considering the nature of the condition, one’s experience in treating the particular condition, and the preferences of the individual patient. The importance of looking at the whole picture, not just the disease or the diagnosis and the treatment, is illustrated in another of Dr. Cochrane’s memories from the war.

He recalls that the Germans dumped a young Soviet prisoner in his ward late one night. The young man was screaming and showed signs of severe lung disease and wounds. Unable to speak Russian and with no morphine for the patient, Dr. Cochrane was at a loss. Instinctively, he sat down on the bed and took the young soldier in his arms, and the screaming stopped almost at once. The young man died peacefully in Archie Cochrane’s arms a few hours later. It wasn’t physical illness and injury that caused the screaming, but loneliness. He considered it a wonderful education about the care of the dying. Dr. Cochrane was ashamed of his misdiagnosis and kept the story a secret for many years.

Dr. Cochrane’s experiences formed the foundation for both the Cochrane Collaboration and the evidence-based health care movement. He also passed on to posterity the importance of using sound judgment together with evidence to make the best possible clinical decisions.

For more information about Dr. Cochran and the Cochran Collaboration, go online to www.cochrane.org.

If you would like Trisha O'Hehir to speak at your next meeting call (480)598-0001 or email trisha@farranmedia.com

The Four “E’s” of Research

Many years ago a colleague of mine, Frances Doherty, RDH, MS, and I tried to figure out the difference between efficacy and effectiveness. At that time the terms were being used interchangeably. We were both visiting the University of Minnesota as guests of periodontist Dr. Bashar Bakdask. When asked, he couldn’t give us distinct definitions of those elusive terms and our search of several dictionaries and research texts at the time were also of no help. It seemed to us the words must mean different things, but finding those differences was elusive.

Over the years, I’ve continued to use the terms interchangeably. That’s finally changed, because I found the answer I’ve been looking for in an excellent article, written by Jean E. Suvan, a hygienist and friend of both Frances and mine. Jean recently completed her master’s degree at Oxford University in England in––guess what––Evidence-Based Health Care! Her article appears in Volume 37 of Periodontology 2000, a prestigious and highly respected journal published in Europe.

Jean’s article is entitled, “Effectiveness of Mechanical Nonsurgical Pocket Therapy.” For this she reviewed 191 review articles on the subject, narrowing it to 12 systematic reviews. This article is an in-depth look at the effect and effectiveness of dental hygiene instrumentation.

To set the stage for her review, Jean eloquently described the differences between the four “E”s and the importance of each when evaluating the research. Here they are in a nutshell:

• Effect: What happens – healing as measured by reduced bleeding or reduced pockets
• Efficacy: How much the effect happens in a controlled environment – how much healing occurs in a controlled study
• Effectiveness: How good is it when used in everyday situations
• Efficiency: Cost-Benefit ratio – the value realized for the time, effort and money invested

You’ll still hear these terms used interchangeably, but knowing the definitions and distinctions between these words will increase your understanding of research reports and product claims. Have fun using these terms next time you talk with a product representative, ask them: “What is the effect of your product,” “Can the efficacy be matched in effectiveness,” “What level of efficiency can I expect in my practice using your product/technique?”