The Placebo Effect

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Surv Ophthalmol 44 (4) January–February 2000

ceps (e.g., Kansas forceps) can remove almost all lens remnants through a 5- or 6-mm incision. They create no eddy currents. Larger nuclear remnants can be manually sectioned before removal. Alexander P. Sudarshan, MD Brownsville, Texas, USA PII S0039-6257(99)00128-9

Reference 1. Monshizadeh R, Samiy N, Haimovici R: Management of retained intravitreal lens fragments after cataract surgery. Surv Ophthalmol 43:397–404, 1999

Authors’ response: We thank Dr. Sudarshan for describing his preferred technique for preventing or limiting vitreous prolapse after posterior capsule rupture with use of two different viscoelastic materials. We agree that, in this setting, the expression of residual nuclear fragments should be avoided. Alternatives, such as the use of lens fragment forceps, would nontheless be categorized as “extracapsular cataract extraction” techniques. Ramin Monshizadeh, MD Gainesville, Florida, USA Robert Haimovici, MD Boston, Massachusetts, USA PII S0039-6257(99)00129-0

The Placebo Effect To the Editor: Margo’s review of the placebo effect begs for a response.4 A report in the Journal of Family Practice states: “Usage of the terms placebo and placebo effect has changed dramatically within medical history. Although placebos are still useful within research, the placebo effect has become a large and ill-defined concept threatening to obscure rather than to clarify whatever phenomenon is being described. Placebo and placebo effects should be fundamentally reconsidered if they are to be of continued use in medical practice.”2 Because health problems tend to resolve over time, it is difficult to measure placebo response. Scientists use the term “statistical regression” to describe the course of natural healing. Researchers now admit that most of the alleged benefits attrib-

LETTERS

uted to the placebo effect are actually “statistical regression.”5 Regardless of these facts, the imagined placebo effect is so ingrained in the minds of medical practitioners today, it is a theory that is difficult to challenge. The placebo effect is conveniently used to explain away the effects of any competing therapy that challenges established or “approved” remedies. For example, when the topic of vitamins is brought up, physicians are quick to indicate that any observed improvement in health status must be due to the placebo effect. But no such connection is made when prescription drugs produce improvement. The placebo effect is an observed response in a group of patients, receiving any kind of therapy, with a wide range of variability. On average, about 35% of patients taking placebo reported improvements. Placebo was not originally described as therapy for individual patients, because 65% of the time or more it would be ineffective. Are doctors to prescribe placebos in an attempt to fool patients? This sounds like fraud or quackery rather than ethical medicine. Has any health care professional actually gone back and read Henry K. Beecher’s original 1955 works on placebo effect, initially published in the Journal of the American Medical Association?1 Recently, German researchers reviewed Dr. Beecher’s original paper. They also reviewed the 15 studies Beecher used to substantiate his theory. Here is what they found: 1. In some studies, no placebo was used at all. 2. In other studies, the patients’ conditions improved as a normal course of their illness, and the improvement was not attributed in any way to the placebo. In one study Dr. Beecher cited, patients who had colds were given a placebo, and about a third of the patients experienced symptomatic improvement within 6 days of being placed on a placebo. But other studies show that about the same percentage of patients experience improvement in cold symptoms by the sixth day of illness regardless of whether they are prescribed a placebo. 3. In another instance, Beecher only pointed to the percentage of patients whose condition improved, not to the percentage whose condition deteriorated. Yes, 35% of the patients improved, but in about 40% of cases the condition worsened. Beecher did not report all of the data. 4. In yet another study, Beecher cited patients who were being taken off a drug and placed on placebo to show that the placebo actually worked. But the patients had experienced drug side effects, which is why they were being taken

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off the drug in the first place. Once the drug was removed, it was likely that the patients’ condition would improve on its own as the side effects subsided. The German researchers went further and examined another 800 studies on the placebo effect published since Beecher’s 1955 report. They found no evidence of the alleged placebo effect. The researchers examined studies that used three groups of patients, a group that was given medicine, a control group given a placebo, and a third group that received no treatment. In these studies, the placebo and “no treatment” groups always matched. There was no significant effect produced by the placebo.3 Isn’t the placebo effect being conveniently used to disguise modern medicine’s own biases? Bill Sardi Diamond Bar, California, USA PII S0039-6257(99)00123-X

References 1. Beecher HK: The powerful placebo. JAMA 159:1602–6, 1955 2. Berg AO: The placebo effect reconsidered. J Fam Pract 17: 647–50, 1983 3. Kienle GS, Kiene H: The powerful placebo effect: fact or fiction? J Clin Epidemiol 50:1311–8, 1997 4. Margo CM: The placebo effect. Surv Ophthalmol 44:31–44, 1999 5. McDonald CJ, Mazzucca SA, McCabe GP: How much of the placebo “effect” is really statistical regression? Stat Med 2: 417–27, 1983

Mr. Sardi is a journalist in the field of health and nutrition and the author of the book What’s Best: A Guide Through Vitamania to Finding the Perfect Multivitamin.

Author’s response: The various issues about placebo raised in Bill Sardi’s letter are not new and were addressed from several perspectives in my review of the placebo effect. His views also have been discussed in consider-

able detail by numerous authors, many of whose works are cited in the bibliography of my article. Mr. Sardis’ letter, however, does remind me of a story about the placebo effect that wasn’t included in my review. Four people were asked to interpret a pharmacology experiment: a psychiatrist, a research scientist, a statistician, and a practitioner of alternative medicine. Each person witnessed a nurse dressed in a white, starched uniform give a blue capsule to a healthy subject. After the young subject swallowed the capsule with a glass of warm milk, he was wished pleasant dreams by the nurse. An hour later the subject was sound asleep. Each participant was told the capsule was filled with table salt and then asked to explain the observed outcome. The psychiatrist said that the young subject was susceptible to the power of suggestion and that sleep was a conditioned response to taking the capsule. The research scientist at first thought the blue capsule was a common sedative and that the pharmacologic properties of the sedative would explain the subject’s lethargy and sleep. This misinterpretation of events was attributed to his research bias. The statistician felt that the young man’s afternoon nap probably reflected participation in more vigorous activities from earlier in the day. The nap, although a deviation from baseline level of alertness, would be an example of regression from the mean. The practitioner of alternative medicine said the table salt caused the subject to fall sleep and considered the experiment a major medical breakthrough. There is an enormous body of evidence showing that the responses to some therapeutic interventions have no known biological basis. Until there is a better understanding of this phenomenon, the mechanisms involved will be subject to a variety of interpretations, some having greater merit than others. Curtis E. Margo, MD, MPH Lakeland, Florida, USA PII S0039-6257(99)00126-5