Do women hurt more than men?

Pain is a medical issue so pervasive that it will impact the majority of Americans at some point in their lives. Here on EBL, we’ve written before about the issue of chronic pain, which effects nearly 116 million Americans.

Now new research out of Stanford University suggests that women suffer more from pain than men, even when both sexes have the same condition.

The study, published this week in the Journal of Pain, is not a systematic review, but it is the largest study of its kind to look at gender issues and pain. In it, researchers analyze the medical records of 11,000 patients whose pain scores were recorded as a routine part of their care.

Of the 22 medical problems analyzed in the study, women reported higher pain levels for 21 of them including back pain, joint pain and sinus infections. Overall, women’s pain levels were about 20 percent higher than men’s. And for several of the ailments, women’s average pain score one point or more higher than men’s – a clinically significant difference.

And it’s not the first study to raise the question of gender differences in pain. An international consensus report in 2007 suggested that hormones may play a role in the brain’s response to pain, and even went so far as to suggest that women may need different analgesia pharmaceuticals than men.

Another study out of England in 2003 suggested women are more sensitive to pain caused by pressure compared to men.

All very suggestive, but this literature on pain and gender differences raises more questions than it provides answers.  As a recent Institute of Medicine report confirms, much more research is needed on the effects of pain.

Stuck in a jam? The science behind traffic

?  So a recent story in the Washington Post about the science of traffic piqued my interest.  It turns out (of course!) there’s an entire field of study around alleviating traffic problems that spans city planning, human behavior and health topics.

There are mathematical models that explain why traffic slows for seemingly no reason at all.  (It turns out these traffic jams are self-sustaining waves, similar to the detonation waves produced by explosions.

Another study has found that it’s actually the rate of merging that contributions to slow-downs on freeways, instead of the capacity of the road.

While there’s much evidence on the causes of traffic congestion, research has pointed to proven solution to solve the problem. But it’s good to know that scientists are working on it.

On a related note, there  is plenty of evidence available on the topic of preventing traffic accidents that lead to injury or death. The Cochrane Collaboration has put together a list of systematic review on various methods to reduce injuries and deaths caused by cars and trucks.  Among them:

Solving issues related to traffic congestion and accidents is just another area where it pays to consult the research.

New evidence on global warming

An international team of researchers have developed a new plan to slow climate change – one that involves reducing levels of two of the lesser-known contributors to global warming.

Their paper, published this week in the journal Science, recommends 14 actions to reduce emissions of methane gas – a greenhouse gas more powerful than carbon dioxide – and black carbon – the technical term for soot, which absorbs heat from the sun’s rays.

Among the measures they suggest are:

  • encouraging people to use switch cleaner diesel engines and cookstoves
  • building more efficient kilns and coke ovens
  • capturing methane at landfills and oil wells
  • reducing methane emissions from rice paddies by draining them more often.

Adopting the study’s recommendations would reduce projected temperatures by approximately 0.5°C by 2050, as well as avoiding millions of premature deaths due to air pollution and increasing crop yields thanks to reductions in ozone.

The proposal is a projection, to be sure.  But there is a large body of evidence available that shows there are many benefits to reducing these contaminants.

Systematic reviews show that reducing soot levels improves lung function and pregnancy outcomes. And it’s been clearly documented that methane gas warms the atmosphere, and that reducing its levels will boost agricultural yields.

So, in fact, the new study delivers another benefit, as noted in this New York Times column: it offers practical solutions with the immediate benefits of improving health and helping farmers produce more.

To us, it seems like a proposal worth putting into practice.

The best thing for kids: A supportive environment

The vast majority of parents – regardless of their income, education or upbringing – want the best for their children. I know that I never imagined the lengths I would go through for another human being until I held a tiny baby in my arms.

This week, the American Academy of Pediatrics issued a policy statement explaining exactly what parents can do to ensure their children’s health and development: avoid toxic stress.

(Before we go on, a quick word about policy statements:  Similar to systematic reviews, they involved a panel of experts – in this case pediatricians – who review the body of evidence on a given topic and make a recommendation based on the available research. So they’re a big deal.)

The statement explains that personal experiences and environmental factors that activate the physiological stress response for prolonged periods of time disrupt children’s brain circuitry and can have an impact on physiology, behavior and health even decades later. Essentially, too many or too long stressful experiences is bad for kids. The statement is referring to major, lasting problems: verbal abuse in the home, a chronic lack of affection for children, physical threats to family members, an addiction problem.

The statement builds on the research of Cornell faculty member Gary Evans, an environmental psychologist who studies the impact of the physical environment and poverty on children. Evans research has shown that growing up in an environment of poverty can lead to health problems.

In another study, Evans looked at the impact of noisy environments on children’s development.

“People tend to think of noise in terms of how it impacts hearing,” he explained. “But if you are subjected to noise, you’re likely to have elevated blood pressure and elevated stress hormones, and those have real implications for your health. Children who grow up in noisy environments are more likely to have deficits in reading because if you tune out noise in general, you also tune out speech. And language is a fundamental building block for learning to read.”

A third study, published in the journal Pediatrics this month, found children who undergo chronic stress have larger gains in their Body Mass Index, suggesting chronic stress leads to weight gain.

The statement makes the arguments that pediatricians – who hold some responsibility for ensuring children’s health – should do more to ensure kids are growing up in health environments. This could mean developmental screenings, connecting families with social services, and supporting community programs that provide positive environments for children.

You can read more about the policy statement and its implications in this New York Times opinion column. And then take the time to make sure the children in your life – whether they’re your own kids, other relatives or neighbors – feel a little more secure and loved. It can go a long way to making a difference in the rest of their lives.

Active kids do better in school

There’s good news out this week for youth who play sports.  A new systematic review published in the Archives of Pediatric and Adolescent Medicine has shown a positive relationship between physical activity and improved academic performance.

Researchers at the EMGO Institute for Health and Care Research in the Netherlands reviewed 14 studies primarily focused on physical education and school sports, but only two met their standards for high-quality scientific research.

The studies, which included children ages 6 to 18, found children who participated in regular physical activity performed better in the classroom. Researchers say that may be because physical activity enhances brain function and thinking skills by increasing blood and oxygen flow to the brain, as well as triggering the release of feel-good hormones like endorphins.

“Besides these suggested physiological effects, regular participation in sports activities may improve children’s behavior in the classroom, increasing the odds of better concentration on the academic content of these lessons,” the review explains.

The paper also notes more evidence is needed to effectively explain the link between physical activity helps kids perform better in school.

In the meantime, the researchers say schools should expand opportunities for kids to be active during and after the school day.

Missing data: The Achilles heel of systematic reviews

If you’re a regular reader of EBL, you know we’re huge fans of systematic reviews – studies in which researchers use sophisticated methods to bring together and evaluate the dozens, hundreds, or even thousands of articles on a topic.

We value these analyses because they collect all of the information available and then look at why and how each study differs. By looking at so many studies, researchers can make general conclusions, even though participants and study settings might be different.

So we took a great interest this week in a series of studies in the British Medical Journal making the case that many medical studies aren’t published, and therefore missing from systematic reviews and the decision-making processes of doctors and patients.

One of the studies found that fewer than half of the clinical trials funded by the National Institutes of Health from 2005 to 2008 were published in peer-reviewed journals within 30 months of study completion, and only 68 percent were published at all.

Another examined trials registered at the federal web site ClinicalTrials.gov during 2009. Of the 738 studies registered and subject to mandatory reporting guidelines (per the rules of the U.S. Food and Drug Administration), only 22 percent reported results within one year.  (It’s interesting to note that trials of medicines in the later stages of development and those funded by the drug industry were more likely to have results reported.)

A third study re-analyzed 41 systematic reviews of nine different medicines, this time including unpublished clinical trial data from the FDA in each analysis.  For 19 of the systematic reviews, the addition of unpublished data led to the conclusion that the drug was not as effective as originally shown. For 19 other reviews, the additional data led to the conclusion that the drug was more effective than originally shown.

Dr. Harlan Krumholz, a cardiologist at Yale and a internationally-respected expert in outcomes research, summarized the issue in his Forbes magazine blog, including some of the reasons that data goes unreported. (Among them, researchers may not be happy with the results or may shift focus to a new study. And medical journals may not be receptive to negative results.)

Whatever the reasons, the take-home message seems to be that researchers and publishers need to do a better job getting all of the information out in the public domain so that doctors and patients can truly make informed decisions.

A new tool to help you lose weight

MyPlateHappy New Year!

Are you making any diet and exercise resolutions this year?  I sure am.

Just in time to help us along, the federal government has launched a new online tracking system.  The system is based on the part of a new, evidence-based initiative to improve the diets of Americans that we’ve written about before here on EBL.

It includes tools to calculate the nutritional information of more than 8,000 foods, tally daily calorie consumption and track physical activity.  You can set weight loss goals, create reports and receive individualized tips about how to improve.

Admittedly, this kind of tool isn’t for everyone.  I know people who crave data – my husband is like this -who love generate graphs and reports showing exactly how many calories they’re consuming and expending. Others find this kind of tracking monotonous and discouraging.

No matter which camp you fall into, the evidence does show that it’s beneficial to track your food consumption – something the new tool will certainly help with. In fact, a systematic review published last year in the Journal of the American Dietetic Association concluded that there is a “consistent and significant positive relationship between self-monitoring diet, physical activity or weight and successful outcomes related to weight management.”  (You remember how much we love systematic reviews, right?)

The article reviewed 22 studies that looked at self-monitoring during weight loss programs.  Fifteen of the studies focused on keeping a food journal, one looked at keeping an exercise journal, and six tracked subjects who recorded their weight at least once a week.

Researchers found that both written and electronic journals helped with weight loss.  They also found that that people kept a weekly record of their weight lost more than those who weighed themselves less frequently.

So if you’re aiming to drop a few pounds in 2012, check out the government’s new tool.  It might be just what you need to jump start your New Year’s resolution.

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