Placebo medication use in patient care: a survey of medical interns.
The use of placebo medication, long recognized by clinicians, often has serious practical implications, such as patient deception. Past evidence has suggested that resident physicians tend to misuse placebo medication. Interns from two consecutive years of a residency program were surveyed anonymously to assess their knowledge and use of placebos. Of the 74 interns surveyed, 44 (59%) were familiar with placebo use in patient care. Fifty percent of these interns familiar with placebo use had learned about placebos from another physician. All interns who had learned about placebos during their internships had learned from another physician, whereas interns who had gained their knowledge of placebos as medical students were as likely to have learned from the medical literature as they were to have learned from a physician (P = 0.027). Interns aware of placebo use were more likely to consider placebo administration for suspected, factitious pain (P = 0.022). The present study uncovered no relationship between interns' estimations of placebo efficacy and the utility they attributed to placebos in assessing a complaint of pain. This suggests that conceptual inconsistencies underlie their use of placebos. Interns often learn of placebos as medical students and are influenced by physician-mentors. Placebo use in patient care is an area of attention for medical educators. (+info
Somatotopic activation of opioid systems by target-directed expectations of analgesia.
We induced specific expectations of analgesia on four different parts of the body to understand how endogenous opioid systems are activated by expectancies. The left hand, right hand, left foot, and right foot were simultaneously stimulated by means of a subcutaneous injection of capsaicin, which produces a painful burning sensation. Specific expectations of analgesia were induced by applying a placebo cream on one of these body parts and by telling the subjects that it was a powerful local anesthetic. In such a way, expectancy of the anesthetic effect was directed only toward the part on which the placebo cream was applied. We found that a placebo analgesic response occurred only on the treated part, whereas no variation in pain sensitivity was found on the untreated parts. If the same experiment was performed after an intravenous infusion of the opioid antagonist naloxone, this highly spatial-specific placebo response was totally abolished, indicating that it was completely mediated by endogenous opioid systems. These findings show that a spatially directed expectation of pain reduction is capable of inducing a specific effect only on the part of the body which is the target of the expectation. Most important, this specific effect is mediated by endogenous opioids, indicating that placebo-activated opioids do not act on the entire body but only on the part where expectancy is directed. This suggests that a highly organized and somatotopic network of endogenous opioids links expectation, attention, and body schema. (+info
Placebo effect in the treatment of duodenal ulcer.
AIMS: To assess whether frequency of placebo administration is associated with duodenal ulcer healing. METHODS: A systematic literature review of randomized clinical trials was undertaken. 79 of 80 trials that met the inclusion criteria. The pooled 4 week placebo healing rate of all duodenal ulcer trials that employed a four times a day regimen was compared with the rate obtained from trials with a twice a day regimen. RESULTS: The pooled 4 week healing rate of the 51 trials with a four times a day regimen was 44. 2% (805 of 1821 patients) compared with 36.2% (545 of 1504 patients) in the 28 trials with a twice a day regimen (difference, 8.0% [equal effects model]; 95% confidence interval, 4.6% to 11.3%). Depending on the statistical analysis, the rate difference ranged from 6.0% (multivariable random effects model) to 8.0% (equal effects model). A number of sensitivity analyses showed comparable differences between the two regimens. Most of these sensitivity analyses were not significant, probably because a number of trials were excluded resulting in a loss of power. CONCLUSIONS: We found a relation between frequency of placebo administration and healing of duodenal ulcer. We realize that the comparison was based on nonrandomized data. However, we speculate that the difference between regimens was induced by the difference in frequency of placebo administration. A better knowledge of various placebo effects is required in order to make clinically relevant assessments of treatment effects derived from placebo-controlled trials. (+info
Pain relief with intracameral mepivacaine during phacoemulsification.
AIM: To assess the efficacy and safety of an intraoperative intracameral injection of mepivacaine, administered when patients experienced pain during the course of cataract surgery under topical anaesthesia. METHODS: This is a prospective placebo controlled double masked randomised clinical trial. 50 eyes were included; 25 receiving the active compound and 25 receiving placebo. Mepivacaine (2%, 0.4 ml) or placebo was administered intraoperatively under the iris of the patients who experienced pain during the course of phacoemulsification in spite of previous topical anaesthesia. Efficacy was evaluated by the patients themselves using a five point subjective pain rating scale, the Keele verbal pain chart. Safety was measured by assessing intraocular inflammation (clinical evaluation and laser flare meter), intraocular pressure, and endothelial cell count. RESULTS: The pain rating score significantly diminished after intracameral injection in the mepivacaine group (mean 3.0 (95% CI 2.6-3.4) v 0.8 (0.3-1.3), p<10(-4))) while remaining unchanged in the placebo group (2.9 (2.6-3.2) v 2.9 (2.5-3. 3)), the mean reduction in pain score being significantly different between the two groups (p<10(-4)). There was no indication of increased postoperative ocular inflammation, intraocular pressure change, or endothelial cell loss. CONCLUSIONS: These results suggest that it may not be necessary to systematically add intracameral anaesthesia with topical anaesthesia for cataract surgery. An intraoperative intracameral injection, performed only in patients who happen to suffer during surgery, is safe and effective. (+info
The physician healer: ancient magic or modern science?
The therapeutic role of general practitioners (GPs) is one that, over the years, has slowly diminished with the growing fashion for evidence-based medicine. However, it is clear that the art of healing and the strength of the doctor-patient relationship play a vital role in improving the well-being of patients. This is exemplified by the placebo effect, where the attitude of the doctor can make an appreciable difference to the psychological response of the patient who feels the need to be understood and listened to empathically. By maximizing the role of the physician healer, there is considerable scope for bridging the gap left by the impersonality of medical science, while at the same time increasing the GP's effectiveness. (+info
Effects of acupuncture on radial artery hemodynamics: controlled trials in sensitized and naive subjects.
Palpation of the radial pulses is an important technique in traditional Chinese medicine. Two double-blind randomized trials of the effects of real and sham acupuncture on radial artery hemodynamics were conducted in 19 patients regularly exposed to acupuncture (sensitized subjects) and in 8 healthy subjects devoid of previous exposure (naive subjects), respectively. Radial artery diameter and pulse waveform were measured with a high-resolution echotracking system and aplanation tonometry, respectively, before and during a 20-min acupuncture period. In sensitized patients, arterial diameter significantly increased during real acupuncture, compared with the sham group (+7.5 +/- 2.8 vs. -2.9 +/- 2.7%, respectively; P < 0.01). By contrast, in naive subjects, arterial diameter did not change during real or sham acupuncture. In both populations, no significant difference was observed between real and sham acupuncture, concerning the time course of blood pressure, radial artery distensibility, and pressure waveform. Our results demonstrate that real acupuncture is associated with an objective vasodilatation of the radial artery in patients regularly exposed to acupuncture, but not in naive subjects. (+info
Unconventional dentistry: Part V. Professional issues, concerns and uses.
This is the last in a series of 5 articles providing a contemporary overview and introduction to unconventional dentistry (UD) and its correlation to unconventional medicine (UM). UD and UM both present important concerns for health care professionals and for the general public. Professional concerns include risks to the practitioner and the patient. UD is of special concern because of the potential harm of invasive dental procedures. Nonetheless, because some UD practices may be of benefit to the patient, decision-making issues and guidelines for UD practice are suggested. (+info
Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment.
BACKGROUND: Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated. METHODS: We conducted a systematic review of clinical trials in which patients were randomly assigned to either placebo or no treatment. A placebo could be pharmacologic (e.g., a tablet), physical (e.g., a manipulation), or psychological (e.g., a conversation). RESULTS: We identified 130 trials that met our inclusion criteria. After the exclusion of 16 trials without relevant data on outcomes, there were 32 with binary outcomes (involving 3795 patients, with a median of 51 patients per trial) and 82 with continuous outcomes (involving 4730 patients, with a median of 27 patients per trial). As compared with no treatment, placebo had no significant effect on binary outcomes (pooled relative risk of an unwanted outcome with placebo, 0.95; 95 percent confidence interval, 0.88 to 1.02), regardless of whether these outcomes were subjective or objective. For the trials with continuous outcomes, placebo had a beneficial effect (pooled standardized mean difference in the value for an unwanted outcome between the placebo and untreated groups, -0.28; 95 percent confidence interval, -0.38 to -0.19), but the effect decreased with increasing sample size, indicating a possible bias related to the effects of small trials. The pooled standardized mean difference was significant for the trials with subjective outcomes (-0.36; 95 percent confidence interval, -0.47 to -0.25) but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect (-0.27; 95 percent confidence interval, -0.40 to -0.15). This corresponded to a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale. CONCLUSIONS: We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos. (+info