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December 2011

The truth, the whole truth, and 'nocebo' effects

Dr Placebo
Last edited 22nd October 2012

Good practice demands that doctors inform their patients about both known and suspected side effects of any medication they prescribe. (In ethics-speak this is because of the requirement to respect patient autonomy.) On the other hand, the very act of providing information about side effects can produce negative effects (these are called ‘nocebo’ effects)! For example in a trial of a drug for unstable angina, patients were divided into two groups. The first group was given a statement outlining possible gastrointestinal (GI) side effects, and the second was not. Six times as more patients in the first group experienced subjective GI side effects.

How can doctors respect patient autonomy by revealing all information about side effects, yet avoid doing harm by causing the very side effects they describe? One answer is to give the information in the right way. We all know people who give negative feedback in a way that tends to increase anxiety. Others give the same information to evoke positive responses. Good teachers, coaches, and doctors all know how to frame information constructively.

Another solution is to ask patients. Some patients do not want to be burdened with details of all known and suspected side effects (serious side effects do, of course, need to be revealed). In these cases we can respect patient autonomy and withhold some information because the patient requested to be (partially) ignorant. Other patients do want to know about each and every side effect, in which case there may be little choice other than to reveal them, albeit in the right way.

So what’s the take home message? Tell the whole truth that the patient wants to hear and nothing but the truth in a way that will maximize benefit and minimize harm.

The recent post on whether Christmas is bad for you inspired further questions on the evidence behind holiday season myths. There is a common misconception that poinsettias (Euphorbia pulcherrima for the botanists) are poisonous. Grandparents tell stories to new parents that they must be vigilant to ensure that children don’t ingest the plant’s leaves.

But what is the evidence?

A study published in 1996 in the American Journal of Emergency Medicine sought to provide an answer. The authors evaluated 849,575 plant exposures reported to the American Association of Poison Control Centers. Poinsettia exposures accounted for 22,793 cases, or nearly 3%, of which nearly all occurred in December and January. Not surprisingly, 94% of poinsettia exposures were in children.

But were they poisonous? No. None were fatal. In fact, only 4% of patients required treatment in a health care facility and fewer than 7% developed toxicity. Most reactions were mild - children that ingested leaves may experience diarrhea and vomiting or have an allergic reaction to the skin.

Poinsettias are not toxic. They don’t stalk family homes waiting for the opportune time to poison children with their attractive red leaves. Children that accidentally ingest poinsettia leaves rarely require treatment. In fact, the real concern is that they may be a choking hazard.

Well what are the real hazards around Christmas time? The Children's Hospital of Philadelphia website highlights the harms that children need to worry about. An unsuspecting culprit took the top spot: alcohol. Alcohol is a serious hazard in children that can lead to major health problems if ingested by children, even in small quantities. Be wary of leaving empty glasses around the house that could break and be ingested by children.

Similar to alcohol if you are in a cold enough climate, windshield washer fluid and antifreeze are serious hazards. The sweet tasting liquid that looks like Kool-Aid can lead to blindness, seizures, heart-rhythm changes and even death if ingested.

Other quintessential botanical Christmas symbols that are poisonous: holly. A handful of berries from the Illex opaca shrub can produce nausea, vomiting, diarrhea and drowsiness in children. The toxicity of kiss causing mistletoe is not supported by the evidence with most cases having a similar outcome as with poinsettia exposure. But with all substances, beware of large amounts.

Be on the look out for disc batteries (coin shaped circular ones) that can be a choking hazard if swallowed. If they become stuck in the esophagus or stomach, they can begin to leak their caustic contents and cause severe burns.

Irrespective of the hazard, most children swallow these objects when they are left unattended. When enjoying the holiday season this year, keep an eye on the curious children putting objects in their mouth and dispel the old urban myths that lack evidence. Happy Holidays.

Is Christmas bad for you?

Kamal Mahtani
Last edited 20th December 2011

Ah, the festive season. One of my favourite times of year: all the family around, food, a bit of time off work, food, the presents, food, The Queen’s speech, food etc. A wave of emotion floods all my senses at the mere thought.

But can Christmas be bad for your health?

First guilty thoughts go to the waist line. So how much weight do we put on during the festive period? In answering that question I came across an observational study in the British Medical Journal from 1985. In it 22 healthy adults and 13 Type 2 diabetics were weighed one month before and one month after Christmas. All participants had an increase in weight which was on average 1.7lbs (0.8kg). The authors suggested that this came from an additional 6000 kcal they ingested over that period. They also found a slight but significant increase in fasting triglyceride and cholesterol concentrations. Although they reassuringly conclude that the results from their study were unlikely to affect any future Christmas.

Slightly more recently, a prospective cohort study published in the New England Journal of Medicine in 2000 suggested we probably don’t put on as much weight as we think we do over the festive period. In the study 195 adult volunteers were weighed at intervals before and after the holiday season, which included the Thanksgiving weekend. The volunteers gained an average of 0.8lb (0.4kg) during the six weeks between Thanksgiving and New Year's Day, which was far less than what they thought they had put on, which was nearer 5lbs (2.3kg).

So perhaps things aren’t so bad then? Not quite. It’s also about what we eat. There is now little doubt of the role that high salt consumption has in raising blood pressure and therefore increasing the chances of having a heart attack or stroke. The Government had set a target to reduce the salt intake of the population to 6g per person per day by 2010. In reality we probably consume more like 9g per day. Apparently it’s worse at Christmas! A survey this month from the Consensus Action on Salt&Health (CASH) found that an average Christmas day of pre-lunch snacks, canapés and a three course Christmas dinner could contain as much as 15.7g of salt. Admittedly the main culprits are processed foods. The survey makes reference to the fact that a significant proportion of salt consumed could be reduced by simply preparing your own vegetables and avoiding adding salt during the cooking. Likewise choosing the low salt equivalents, such as with crisps, may halve your salt consumption. Or how about a Yorkshire Wensleydale with apricot instead of a Creamy Blue Stilton this year? Again half the salt level.

So am I suffering from “Bah! Humbug syndrome”? Far from it! I fully intend to enjoy the holiday season with all of the above. I’ll just keep one eye on how tight my belt feels and perhaps think a little before that second portion.

Happy Christmas.

Emergency contraception: emotion, evidence and bubble gum

Peter Gill
Last edited 18th December 2011

Earlier this year, the FDA recommended that emergency contraception, or Plan B, should be available without prescription to girls under 17 as it is currently available by prescription only to this age group. In an unprecedented move, the US Health and Human Services secretary Kathleen Sebelius vetoed the FDA's recommendation to make Plan B available without prescription to all women of childbearing age in the US. Mr. Obama said the secretary felt a 10- or 11-year-old should not be able to buy emergency contraception “alongside bubble gum or batteries."

What is Plan B or emergency contraception? Plan B is a pill that consists of the hormone progestin that works by preventing an egg from being fertilised. It must be used within 120 hours after unprotected sex, is safe and effective with few side effects and none dangerous.

Unlike some misconceptions, the availability of emergency contraception dose not change rates of sexual activity or increase the frequency of unprotected sex among adolescents.

Unintended pregnancies are an emotional and controversial issue, invoking deep-rooted religious, political and ideological beliefs. The US has one of the highest rates of unintended pregnancies with nearly half of all pregnancies unintended. In particular, adolescent birth rates in the US are much higher than rates in other developed countries.

Side stepping the issue of induced abortion, what is the effect of unintended pregnancy on women? A recent Lancet editorial discussed the results of a comprehensive review into the mental health outcomes of women after having an induced abortion. The key study finding was that having an unwanted pregnancy leads to an increased risk of mental health problems, not having an induced abortion.

The US should be leading the battle to reduce unintended pregnancies. Indeed the American Academy of Pediatrics (AAP) “encourages abstinence plus comprehensive sexuality education as the best way to help prevent unintended pregnancy and sexually transmitted diseases.” Further, they support the availability of emergency contraception, or Plan B, for adolescents.

Given that only 20-25% of health care providers discuss emergency contraception with adolescents, the restriction of Plan B to prescription only to adolescents under 17 seems a major barrier to access.

What is the likelihood that a 15-year-old who had unprotected sex is going to get a prescription for Plan B? She will be able to purchase acetominophen (i.e. Tylenol or Paracetamol) without a prescription, a medication that can potentially cause fatal liver damage and lead to liver failure if used inappropriately, yet she cannot purchase Plan B to prevent an unintended pregnancy.

Rather than rely on evidence, emotion wins. But the real loser are adolescents under 17 who may face life-long mental health problems. When emotion wins, we all lose.

The choice between rail and road:perspectives from Delhi

Ami Banerjee
Last edited 5th December 2011

This week I started a 3-week research trip to India, based at the Centre for Chronic Disease Control in New Delhi. Yesterday I rediscovered the joy of train travel. My morning began with a ride on the efficient Delhi metro at 6.15am. The service is state-of-the-art in South Asia, and in my view, compares very well with similar services in many high-income countries. Alongside the option of driving, sitting on the train from Delhi to Chandigarh was not only much more relaxing, but I actually had the time to take in the views as we travelled through colourful North Indian villages.

Contrast this with the situation on India’s roads. Even in urban centres such as Delhi, the chaos of road traffic makes you wonder at how survival statistics are not worse. India has a higher rate of road traffic accidents (RTAs) than anywhere in the world, according to the World Health Organisation’s report last year, with 14 people dying every hour on the road. Globally, RTAs make up a third of unintentional injury deaths, with double the death rate and three times the burden of disability in low-middle income countries compared with high-income countries, which are less able to cover the huge economic and social costs. Children are more likely to be victims, and RTAs are projected to be fourth leading cause of death in 2030.

One recent post-mortem study from Kolkata found that a staggering 63.1% of deaths were due to accidents, mostly on the roads. The dire circumstances which can result from RTAs are shown by a case report from Jaipur, India, simply titled, “An unusual presentation of head injury: teeth in brain”.

Interestingly, an analysis from the UK estimated that walking to and from stations accounted for 65% of the overall door-to-door risk of being killed on rail journeys; with the rail system itself accounting for only 21% of the risk. In other words, it is the risk of the road which causes deaths on trains in England as well. There are calls for better data globally, since only 20 countries have the high-quality data needed to accurately estimate mortality from RTAs but I think I have read enough. I will use the train whenever possible. The urgent message for Indian policymakers is that a comprehensive policy for road safety is required and fast.

Self-monitoring of blood thinners halves your risk of clots

Carl Heneghan
Last edited 1st December 2011

Here are some links to news stories of cebmblog and colleagues work published in the Lancet today

Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data Lancet

Self-Monitoring of Blood Thinner May Halve Clot Risk
MSN Health
People taking the blood-thinning drug warfarin who monitor their own blood and adjust their dosage can reduce the risk of blood clots by half, British researchers report. Warfarin is taken to prevent potentially deadly clots in patients with conditions such as atrial fibrillation – an abnormal heart rhythm – or a mechanical heart valve. But if the blood is thinned too much, serious bleeding can occur. Keeping the drug in check requires monthly monitoring and frequent doctors visits. ‘The concept of self-care and self-monitoring is a growing part of health care. It is used widely in diabetes, asthma and hypertension management,’ said lead researcher

Dr Carl Heneghan, director of the Centre for Evidence-Based Medicine at the University of Oxford. ‘The evidence shows that self-monitoring is an effective strategy to reduce thromboembolic events in patients taking oral anticoagulants such as warfarin,’ he added.

Home monitoring of ‘blood thinners’ is effective
Web MD

Patients Can Safely Manage Blood Thinners Themselves
MedPage Today

There is also a neat peice by Jonathan Wood from the University of Oxford press office Blood clot risk halved for patients checking own warfarin dose

Patients who monitor their own treatment with warfarin or other blood-thinning drugs reduce their risk of developing blood clots by half, an Oxford University study has found.......

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