Earlier this month, I presented the updated colon cancer screening guidelines and commented how virtual colonoscopy may improve screening rates due to its less invasive nature than the traditional colonoscopy. My premise was that patient discomfort served as a primary deterrent to higher rates of colonoscopy use. Data from a recently published Vanderbilt study, however, beg to differ and suggest that other factors account for the inadequate rates of colon cancer screening in the United States.

The study population was derived from the Southern Community Cohort Study (SCCS), a large research endeavor to characterize cancer trends and disparities across racial and socioeconomic backgrounds. The group comprises 51,454 patients (ages 40-79 years) collected from 48 community health centers. The exclusion criteria for this particular study included the following: race other than African-American or Caucasian; uncertainty of whether the patient has had a sigmoidoscopy or colonoscopy; and, uncertainty of family cancer history. This left 41,830 participants, who were surveyed on personal demographics, personal history of colorectal polyps, family history of colon cancer, patterns of undergoing screening endoscopy, and last visit to a health care provider.

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It almost seems that a million-and-one books are published everyday touting the secret to rapid and sustained weight loss. But, how many of these diet schemes have been verified to produce the results they advertise? In the latest JAMA (Journal of the American Medical Association) issue, a group of academic centers involved in the Weight Loss Maintenance (WLM) initiative published their results from a three-year study comparing strategies for sustaining weight loss. The project is sponsored by the National Heart, Lung, and Blood Institute (NHLBI), and includes four clinical centers: Duke University, Johns Hopkins University, Pennington Biomedical Research Center, and the Kaiser Permanente Center for Health Research.

The design of the WLM clinical trial involves two phases. Phase 1 comprises a 6-month period where all participants undergo similar intervention to obtain weight loss. Working closely with a trained interventionist, the group strives to achieve a weekly weight loss goal of 1-2 pounds per week through a combination of strategies, such as caloric reduction, dietary modification, and increased physical activity. After having lost weight in phase 1, participants in the 30-month phase 2 trial are randomly divided into three groups, each with a different level of intervention to encourage maintenance of weight loss: 1) minimal intervention; 2) technology-based intervention, with use of an interactive website which sets personal goals, action plans, and provides an online support community; and 3) personal-contact intervention, involving monthly contact with a weight-loss interventionist.

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It was not long ago when mobile phones were considered luxury items or tools reserved for corporate executives. A decade and a half later, every Joe, Jane, and their child now sport a cell phone or some multimedia-capable variant thereof. Fortunately for the general populace and myself, a recent case-control study done in Japan has shown no significant relationship between mobile phone use and brain cancer. There have been many other studies with similar findings, but this is the first to further analyze the spatial relationship between radiofrequency exposure and tumor location.

The case population included 322 patients newly diagnosed with a brain tumor (88 with glioma, 132 with meningioma, and 102 with a pituitary adenoma). They were pooled from neurosurgery departments throughout Tokyo and 25 neighboring cities. The control group comprised of 683 healthy volunteers who were randomly contacted by cell phone. From both groups, the study participants were interviewed on their patterns of cell phone use: type of phone, length of use, average duration per call, frequency of calls, etc. Use of cordless telephones was also considered. The study further analyzed the 3D spatial relationship between source of radiofrequency exposure and location of tumor. These data were used to estimate a specific absorption rate (SAR) within the tumor.

The study did not find a significant increase in the odds (presented as odds ratio with 95% confidence interval) of the three tumor types with typical use of mobile phones. There was no significant difference found in incidence of tumor with increased cumulative time of use. There was also no substantial increase in risk when analyzing subgroups according to mean levels of maximal SAR. The researchers therefore conclude that there was “no increase in overall risk of glioma or meningioma in relation to regular mobile phone use among [their] Japanese subjects“.

It is interesting to note how the general public had embraced mobile phones long before learning of its relative safety. Could this be attributed to our collective state of denial (”it won’t affect me“), the immense utility and convenience of the device overweighing any potential health risks, or the sheer skill of the Sprint-Verizon-Cingular- marketing machine? Fortunately, most research studies have so far dismissed links between mobile phone emissions and brain cancer. But what if they didn’t?

Related Post: Mobile phones are safe in hospitals

• Source
• Takebayashi T, Varsier N, Kikuchi Y, Wake K, Taki M, Watanabe S, Akiba S, Yamaguchi N. Mobile phone use, exposure to radiofrequency electromagnetic field, and brain tumour: a case-control study. Br J Cancer 2008;98:652-9.

At many a doctor’s visit, there is often an expectation that the patient goes home with a pill to “fix” the problem. It represents a tangible reminder that the physician has done something — anything — to address the presenting need. There are many scenarios where the use of medication can be easily justified (e.g., high cholesterol, uncontrolled diabetes, hypertension). There are also scenarios where prescribing a pharmacologic agent may be more controversial, such as whether to use of antibiotics or steroids in sinus infections.

In light of growing bacterial drug resistance, and the lag in development of novel antibiotics, there are good reasons to take a conservative approach to prescription writing. Moreover, since current antibiotics predominantly target bacteria and not viruses, the need for antibiotics in infections that are typically viral becomes unclear. Do you empirically treat an infection with drugs or allow the body’s immune system to clear the pathogen on its own?

A randomized controlled study recently performed in the UK tries to address the question of whether antibiotics and/or steroids are beneficial in acute sinusitis. Between 2001 to 2005, 240 adults with
new onset, non-recurrent sinusitis were randomly divided into four groups: treatment with antibiotics (amoxicillin) and nasal steroids (budesonide); placebo antibiotic and steroids; antibiotics and placebo
steroids; and double placebo. The study found that 29% of patients given antibiotics vs. 33.6% without antibiotics experienced symptoms for 10 days or longer. The comparison between steroid and no-steroid use
showed an identical proportion of patients (31.4%) in both groups with symptoms 10 days or longer. The differences are noted to be insignificant.

The authors’ conclusion? . . .

among patients with the typical features of acute bacterial sinusitis, neither an antibiotic nor a topical steroid alone or in combination are effective in altering the symptom severity, the duration, or the natural history of the condition.

Although the small sample size is a limitation of the study, this is purportedly the largest non-pharmaceutically funded study to address the question. Another limitation of the study includes a lack of differentiation between bacterial or viral infections. As mentioned earlier, most viral infections do not typically respond to our current armamentarium of antibiotics.

More research is necessary to validate the results and conclusions. They nevertheless illustrate a point that sometimes no medicine is the best medicine. Of course, there are many more times when directed pharmacologic therapy is vital for a good outcome. But, I would best leave it to the doctor to decide.

• Source
• Williamson IG, Rumsby K, Benge S, Moore M, Smith PW, Cross M, Little P. Antibiotics and topical nasal steroid for treatment of acute maxillary sinusitis: a randomized controlled trial. JAMA 2007;298:2487-96.

Similar to the controversy about whether cellular phones can cause brain cancer, there is brewing debate about whether these phones also affect medical devices. In two earlier articles discussing research findings from the Tan Tock Seng Hospital (Singapore) and Mayo Clinic (Rochester, Minnesota), I reported that mobile phone use was not detrimental to medical equipment. Similar studies have prompted the reversal of cell phone bans in many hospitals throughout the United States.

Just as we have become comfortable chatting on the phone while walking from patient room to the cafeteria, a new Dutch study presents a caveat to the earlier reports. While it is true that newer generation mobile phones may generate less electromagnetic interference (EMI) due to better shielding and signal downregulation, there is limited information characterizing the risks of using Internet-capable phones around medical devices.

To explore this question, researchers from the University of Amsterdam utilized wireless signal generators to mimic data transmission on modern mobile phones. The generators were placed in proximity of medical devices commonly found in the ICU, such as telemetry monitors, mechanical ventilators, and infusion pumps. The group detected 48 incidents in 26 devices (43%). Sixteen (33%) were classified as hazardous, 20 (42%) as significant, and 12 (25%) as light. The median distance of effect was 3 cm (range: 0.1 to 500 cm). Some hazardous effects included ventilator shutdown, restart, and setting adjustment. A syringe pump also stopped without an accompanying alarm. These were not trivial events.

One limitation of the study is that the group used signal generators at maximum power to assess the potential risk of cell phone use. Since mobile phones frequently regulate its power output based on the carrier network’s signal strength, we would expect lower EMI in real-world conditions. On the other hand, since the group’s aim was to characterize possible worst-case scenarios, this criticism is moot. Besides, deep inside the behemoth of a hospital, signal strength is usually weaker and EMI inversely stronger.

In brief, although newer generation Internet-capable smartphones present new challenges of electromagnetic interference, a one-meter buffer between phone and medical device still seems reasonable. Now to publish this article via my CrackBlackberry before I get too close to Mr. Johnson’s ventilator.

• Source
• van Lieshout EJ, van der Veer SN, Hensbroek R, Korevaar JC, et al. Interference by new-generation mobile phones on critical care medical equipment. Critical Care 2007;11:R98.

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Since the FDA (Food and Drug Administration) does not regulate dietary supplements as stringently as pharmaceutical drugs, manufacturers of the former can market their products with untested and unsupported claims. While some claims border on fantasy and may breach ethical standards (”pill that cures all cancers”), most claims are plausible. Calcium and vitamin D supplements may build bones. Iron sulfate may help with some forms of anemia. But, do we know whether the supplements truly provide their advertised effect?

Chondroitin sulfate and glucosamine have long been marketed as substances to alleviate the arthritides. This is a reasonable conjecture, given that chondroitin sulfate is a polysaccharide found in joint cartilage. One would logically assume that oral supplementation of this substance would help replenish eroded joints. Even the Mayo Clinic states that “consensus of expert and industry opinions support the use of chondroitin and its common partner agent, glucosamine, for improving symptoms and arresting (or possibly reversing) the degenerative process of osteoarthritis.” The Mayo Clinic, however, does not go so far as to fully endorse chondroitin use. It admits that “(s)afety and effectiveness have not always been proven”.

So, does it work? A meta-analysis published this week in the Annals of Internal Medicine hopes to address the question and controversy. The study included 22 independent research trials examining the efficacy of chondroitin use with osteoarthritis of the knee or hip. Twenty trials (3846 patients) had sufficient data to calculate effect of chondroitin use on joint pain. Twelve trials were used to assess adverse events, and 5 trials reported radiologic measurements of joint space width.

The authors understand the limitations of their study and concede to the variable experimental and reporting methodologies among the trials. They nevertheless assert that the “large-scale, methodologically sound trials indicate that the symptomatic benefit of chondroitin sulfate is minimal or nonexistant. Use of chondroitin in routine clinical practice should therefore be discouraged.” On the flip side, they did not identify any significant adverse effect. I suppose one downside of continued use would be wasted money.

In our subjective world, evidence-based medicine does not always determine our health choices. As long as there are proponents of chondroitin use, and deep pockets to keep the marketing campaigns moving, the sale of chondroitin and similarly questionable supplements will retain their presence on store shelves. At least we have the freedom of choice.

• Source
• Reichenbach S, Sterchi R, Scherer M, Trelle S, Burgi E, Burgi U, Dieppe PA, Juni P. Meta-analysis: chondroitin for osteoarthritis of the knee or hip. Ann Intern Med 2007;146:580-90.

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Last year in February, I reported on a Singaporean hospital’s conclusion that mobile phones posed no significant risk to medical equipment. That same month, clinical and telecommunications researchers at the Mayo Clinic (Rochester, Minnesota) began a four-month study to evaluate for interference by cellular phones on medical equipment. After 300 tests on 192 medical devices, the researchers published their conclusions in the Mayo Clinic Proceedings (March 2007):

Although cellular telephone use in general has been prohibited in hospitals because of concerns that these telephones would interfere with medical devices, this study revealed that when cellular telephones are used in a normal way no noticeable interference or interactions occurred with the medical devices (emphasis added).

Interestingly, the same group published two similar studies in 2001 and 2005. Their earlier conclusions were less direct, noting possible interference from mobile phone use. In the 2001 study, they discovered that cell phones caused interference in 55% of the tests, affecting 41% (7/17) of the medical devices. The interference was considered clinically relevant 7.4% of the time, comprising “interference that may hinder interpretation of the data or cause the equipment to malfunction.” The 2005 study showed more promising results. While the number of devices affected remained constant at 44% (7/16), the incidence of clinically important interference dropped to 1.2%. This year, the incidence is reported at 0%.

Newer cell phone models presumably emit less electromagnetic interference (EMI), explaining the progressive decline in interference found among the three studies. The results are not novel, but they bolster the current belief that cell phone use is acceptable in hospitals. In fact, I have noticed a higher density of newfangled Motorola Razrs^® and Palm Treos^® in hospitals than in any community setting. I also know several physicians who have traded their antiquated pagers for the PDA-pager-phone-Batman buckle combos.

• Sources
• Tri JL, Severson RP, Firl AR, Hayes DL, Abenstein JP. Cellular telephone interference with medical equipment. Mayo Clin Proc 2005;80:1286-90.
• Tri JL, Severson RP, Hyberger LK, Hayes DL. Use of cellular telephones in the hospital environment. Mayo Clin Proc 2007;82:282-285.
• Tri JL, Hayes DL, Smith TT, Severson RP. Cellular phone interference with external cardiopulmonary monitoring devices. Mayo Clin Proc 2001;76:11-5.

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A Turkish study, published in the British Journal of Sports Medicine, recently reported the presence of occult hepatitis B virus (HBV) infection in 13% of Turkish Olympic wrestlers. Occult HBV infection is the detectable presence of virus through PCR (polymerase chain reaction), despite the lack of a viral protein called HBsAg (hepatitis B surface antigen) in the blood. The current standard for evaluating hepatitis B infection or immunity relies on measuring hepatitis antibody and antigen markers. By definition, the standard tests used in hospitals did not reveal hepatitis B in these wrestlers even though they were infected. Interestingly, 11% of the wrestlers also secreted HBV in their sweat.

Several studies estimate the HBsAg positivity (indicator for acute or chronic hepatitis B) to be roughly 7% in Turkey. This figure is less than the prevalence of occult HBV found in the wrestlers. For comparison, low-risk regions, such as the United States and Western Europe, have an HBV prevalence of <2%.

Although more studies are needed, it is interesting to speculate the significance of the recent findings. For one, there may be a higher prevalence of hepatitis B infection than earlier believed. It is not standard of care to test individuals for HBV DNA. The occult HBV category may comprise a large yet underdiagnosed group. On the other hand, by nature of their profession, wrestlers sweat copiously and engage in prolonged bodily contact. Their increased risk for exposure could have contributed to the increased prevalence in this population.

Hepatitis B possesses several modes of transmission: maternal-fetal, mucous membranes, exposure to blood via needlestick injuries or contaminated transfusions, and transplantation. Excessive bodily contact has been suggested before as a form of transmission, particularly in children, but the data are unclear. With the finding of HBV DNA in the sweat, we wonder whether this supports transmission through bodily contact and fomites. Should we be concerned about it? Our knowledge in this area of study is still superficial. I am only aware of a few groups engaged in epidemiologic and laboratory-based research of occult HBV. It is nevertheless possible that wrestlers in endemic areas may someday need to get vaccinated prior to participation in sports.

• Sources
• Bereket-Yücel S. Risk of hepatitis B infections in Olympic wrestling. Br J Sports Med 2007.
• Maynard JE. Hepatitis B: global importance and need for control. Vaccine 1990;8 Suppl:S18-20.
• Mehmet D, Meliksah E, Serif Y, Gunay S, Tuncer O, Zeynep S. Prevalence of hepatitis B infection in the southeastern region of Turkey: comparison of risk factors for HBV infection in rural and urban areas. Jpn J Infect Dis 2005;58:15-9.

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