From the Old to the Young

In a similar vein as my recent post about the 91-year-old athlete and the benefits of more intensive exercise for the elderly, I saw this article looking at the benefits of weight training for children. It is generally recommended that children and adolescents don't participate in weight-training. The initial reasoning was that child-laborers in Japan had stunted growth and it was assumed that heavy lifting was the cause, but new research suggests that this may not be the case. In fact, new studies show that weight-lifting can be incredibly beneficial for youth. Unlike adults, who generally gain muscle with strength training, children reap neurological advantages. Their muscles and neurons begin to interact much more efficiently.

In the distant past children had built-in weight training with farm chores, but very few children these days have that option. (I was fortunate to grow up carrying 5-gallon buckets filled with feed and water and wrestling lambs)

Should we change our recommendations?

Scientific support for the love of my life

...the furry, four-legged one that is.

If you've read many of my posts and noticed my [mild] obsession with my dog, Zephyr, you probably expect that I get really excited when I come across scientific studies regarding the benefits of pets!

On a purely anecdotal level, my dog has huge benefits for me. He forces me to get out and exercise every day;  not just moderate exercise, either. To control his energy level I get the full-out very vigorous label. And to keep up with all his exercise needs I have to keep myself well-nourished. I can't spend all day asleep in bed, Zef is bouncing atop me by 10 a.m. (it used to be 6, so we're making progress).

And it's hard to have a bad mood around him. He loves life from the moment he wakes up; everything (even nail trimming) is turned into some type of game. Making a bed? He hides under blankets. Drying his feet? the towel become a tug rope. Throwing anything in the air? It's a game of fetch! (true story, one time I was tossing a rolled-up pair of socks and he caught them and swallowed them). I've also learned to "go with the flow" and that most "emergencies" aren't really things to get stressed about. In addition to the socks he has eaten a bar of soap, a highlighter, hairties, a sharpie, a plastic frisbee (yep, actually swallowed the pieces), he licked a razor blade, sliced his foot on a piece of tin roofing, and has broken a front tooth.

To get an idea of what his personality is like, check out the video below. 

Of course, he's no therapist. And it's not to say he's without stresses (finding a place for him to stay when I travel, food, vet bills [fortunately my mother's a vet], training, and other time/financial investments). Many people told me I should wait to get a dog. Do I wish I had paid more attention to their advice? Some days. Would it change my decision? No. I'm not saying that everyone should get a dog. I really think each individual needs to closely examine how much effort and stress they're willing to take for a pet, but in my case I can never be fully happy without a dog. And there is no way in the world I would give me dog up.

And I try not to get too freaked out by studies that show therapy dogs may spread MRSA and CDiff. Or the medical and training controversies fueled by pets sleeping in the bed (you better believe that Zephyr owns my queen-size bed). Or the ridiculous amount of vacuuming I do every week. Or the amount of money I spend on tennis balls and frisbees.



But how can you look at this face and continue to worry about all that?

Or even just see that silly little bob-tail.

~L

Old? Hardly.

So this weekend, (instead of you know, reading or studying). I wrote a whole bunch of blog posts! I don't want you all to be overwhelmed and binge on my awesomeness, so I'm keeping them in the background and releasing them one at a time. I have posts set for the next couple weeks and I always have more ideas that I will continue to draft. But having this head start makes me really really happy. It should make you happy too because it means that I will be posting more regularly (you should also be happy that this means most of my posts receive a second round of editing ;)

Read up!

Starting off, thoughts on an article in the NY Times (my favorite newspaper in case you hadn't noticed).

This lady is a rock star. At 91-years-old she continues to compete in "masters" track events. And not just compete, she blows away the competition. Master's track competition begins at the age of 35 and performances are compared using age-graded tables that turn times/distances into percentiles when compared to other athletes in the same age group. Olga's percentiles run at 100% (or more, since the tables are new because of how few athletes in her age group compete). She often beats athletes who are in age-groups one or two classes below her own.

Many scientific disciplines are studying her to determine why she performs better than her peers. There may be some inherent genetic/physiological factors specific to her, and that is being looked into. What interests me, however, is the theory that intense exercise makes a bigger difference on the aging process than the moderate exercise that is generally recommended for the elderly. The reason for this recommendation is to prevent injuries (which are more likely as people age). But if one can find a balance between training hard enough to see the most gain and moderately enough to avoid injury, they can reap the most benefit.

So should we start encouraging older people to exercise more intensely? Are we recommending a sub-optimal level? Or are we being responsible and not encouraging people to test limits (and thus risk injury)?

Weight Loss Programs and Insurance

Another set of two articles to ponder.

The first comes from the Consumer Reports Health Blog: Commercial Weight-Loss Programs: The Evidence

The second comes from Dr. Judith Wurtman on the Huffington Post: Weight Loss: Should Commercial Programs be Covered by Health Insurance?

It's one of those never-ending battles: do weight-loss programs actually work? Some say they do, some say they don't, others say they only work short-term or never allow the participants to have a "normal" food life without gaining all the weight back. And what is the scientific evidence for them? Strangely, there have been very few studies. The blog post from Consumer Reports looks at two recent studies in the Journal of the American Medical Association (JAMA) that looked at lifestyle interventions and prepared meals to help with weight-loss.

The first study lasted one year and split the participants into two groups. The first group had diet and physical activity interventions for the full year, the second group started with just a diet intervention and started physical activity six months later. The results? The group that did both diet and exercise initially had a greater weight-loss at the six-month mark, but after adding exercise, both groups had similar weight loss at the twelve-month mark.

I'm not sold on the study design. I think delaying the exercise in one group, but still having both groups do it, confounds the results. The initial intention wasn't to determine if delaying exercise had any effect on weight loss; it was looking at the efficacy of diet and exercise interventions. If I were planning this study I would have one group with only a diet intervention, one group with only a physical activity intervention, and one group with both interventions. This would (hopefully) allow the researchers to determine which type of intervention, or combination of interventions, was most effective.

So a structured diet and exercise plan works, and helps the participants keep the weight off for at least a year. What about the other study? This study was looking at the effect of pre-packaged meals as part of a structured weight-loss program (this study was funded by Jenny Craig). It compared two groups: one that received ongoing support in addition to prepackaged meals during the initial weight loss, the other group received standard obesity counseling and monthly "contact." The group that received meals and structured support had greater, sustained weight loss.

I like a couple things about this study. First, I like that the two groups were clearly defined; there wasn't any crossing-over with their interventions. Second, a two year follow-up gives a better picture of whether the intervention worked in the long-term. I'm not necessarily a fan of prepackaged meals. I question whether people would actually follow the program if they had to pay the inflated price for all of these meals (the study participants received them for free). And I don't like the idea that people aren't taught the principles of feeding themselves with real, fresh food. I'll be honest, I'm not familiar with the Jenny Craig plans and their prepackaged meals. Perhaps participants are taught the basics of good nutrition, maybe they do learn what to prepare for themselves after the packaged phase. But I'm hesitant. Will these people become reliant on a company to tell them what to eat to stay "healthy" (read: thin). Will they trust their own instincts on feeding themselves? What lessons are they passing on to their children with this? And there are a few bigger issues: the disparity created by those who can't afford these programs and concerns related  to packaged foods. I worry about added salt, sugar, preservatives, and the loss of the concept of real food. (I would love to go on about my views of nutrition, health, weight, and food, but that is best left for another post...or series of posts)

And what to do with this information? This is where the second article I linked to heads: should insurance companies cover weight-loss programs? Insurers are willing to shell out big bucks for obesity drugs and surgeries. Why? Because obesity costs them. And why won't these same companies pay for commercial programs? I'm at a loss there. It appears that it is a cheaper, effective alternative (probably not as effective as surgery, but one could argue that it is more cost-effective). I wonder if the companies see less weight loss as less healthy. I personally think fitness is preferable to thinness and I would presume that diet/exercise programs would achieve that better than surgery. It's an argument that could go around and around.

Thoughts?

~L

Social Networks and Health (Anthony Paik)

I should probably start this with a disclaimer—this is not intended to be an in-depth description of the use of social networks for research. It is simply my rehashing of a departmental seminar that has been filtered through my statistics-challenged brain (I finished all my college math in high school and did my undergrad studies in music so it has literally been years since I studied math with any intensity)

First of all, why do we even want to study social networks? Networks can give different views of a subject than standard data alone can. Networks allow us to see how structure matters, separate metaphors and concrete differences, attributes vs. relations, study how an individual's choices constrained by the social structure they reside in, and compare micro and macro views of the same data.

Visualizing Network Data

Network data can be viewed as both a graph and matrix. Graphs are made by plotting nodes and denoting connections using lines. In one type of graph, known as spring and bedding, nodes are pulled closer by the presence of ties. A matrix corresponds to a graph and numerically describes connections between nodes. (See my extremely simplified, rather rough examples of a graph and matrix below)

	N1	N2	N3	Etc…
N1	-	1	0
N2	0	-	1
N3	1	1	-
Etc…

            1=connection between nodes

            0=no connection

 

After creating visualizations of the data we can then describe and analyze it. The different ways of describing are by composition and structure. Composition would focus on the alters (or nodes) that make up the bedding of the data. Structure can be looked at different ways. By density (less dense areas vs. more dense areas), modal degree, distance between nodes, similarities or patterns of ties.

 

Analyzing Network Data

There are three basic types of data analysis

    Dyadic analysis involves gathering information from a pair of alters

    Egocentric analysis is the collection of data around a single node

    Complete analysis looks at all the information from everyone

The tools that can be used to assist in these types of analysis are visualizations, cultures and subgroups, the network as a dependent variable (this looks at the probability of tie formation in the network), network as the independent variable (this looks as contagion and influence including the flow of information, power/authority, cohesion/solidarity, and competition/comparison)

Networks, like any research, are not perfect. One common issue is the homophily or selection problem. The question with this problem is "did the friendship form on the basis of the variable being studied?" There is a tendency for people with same characteristics to become friends so this is a very real problem. Another issue is confounds—are the results related to a larger contet (e.g. environment) that is shared by both alters?

 

Health Implications

This is where network research appeals to public health practitioners. And I thought this portion of the lecture helped me understand the previous intro to networks. Following is a brief review of actual research using each of the three basic types of network analysis.

Dr. Paik described his research utilizing a longitudinal study of adolescent health (ADO Health)—Wave 1 occurred in 1994-95, with subsequent waves in 96, 01, 04

Examples of the different types of data collection used:

    Dyadic data—interpersonal violence

    Egocentric—sexual concurrency, chlamydia infections

    Complete—peer effects of nonromantic sex

Dyadic data collection to evaluate interpersonal violence:

The independent variable was the partner's prior violence from Wave I. The dependent variable was the victimization of the alter in Wave II. A positive correlation was seen, which essentially means that a partner with a history of violence is more likely to continue to be violent.

Egocentric data collection to determine the connection between sexual concurrency and chlamydia infections:

The dependent variable here is a chlamydia infection. The independent variable was the presence of concurrent (multiple) sexual partners. A positive correlation was seen between these variables. As many people would assume, more prior partners increased infections, but having concurrent sexual partners had an even larger increase in infections.

Using the network to find patterns regarding nonromantic sex and delinquency:

The dependent variable in this example is having nonromantic sex during Wave I (or "hooking up" in laymen's terms). Two different analyses occurred using the mean of friends' delinquency as the first independent variable and the network centrality of the respondent weighted by the centrality of his/her friends as the second independent variable.

As one might assume: the respondents' delinquency had a positive effect on the occurrence of hook-ups as did the mean of the friends' delinquency. Simply looking at the friends' centrality showed no effect, but weighting centrality with delinquency showed two differences: having delinquent and central friends increased the odds that a respondent would hook-up but having delinquent, non-central friends actually decreased those odds.

Further analysis?

    Are hook-ups contagious as the data seems to suggest?

To look at this they looked at the ties found between those who have never hooked up, ties found between those who had hooked up and those who had not hooked up, and the ties found between people who had had hookups.

    Hook-ups did appear to be "contagious". These findings can then be put to use from a public health perspective.

 

Admittedly, this overview of social networks is extremely simplified and possibly just plain wrong, but if it has piqued your interest in networks Dr. Paik suggests a few books that are helpful for learning more.

    Networks and Health by Tom Valente

    Networks an introduction by Mark Newman

    Networks, Crowds, Markets by Easley/Kleinberg

 

 

Coming up—a brief interview with Dr. Paik

 

~L

Isolation

I have come across both of these articles recently. Working in the hospital isolation is a big deal so of course I looked at them.

From the AMA: Preventive Measures Shown to Cut CDiff Rates

And in the NY Times: When Isolation Hampers More Than Bacteria

As a bit of background, in a hospital someone is put into isolation when they are infected with MRSA, VRE, Chlostridium Difficile, or any other hospital-acquired infection. The patient is required to be placed in a private room. Everyone who enters the room is required to wear gloves and an isolation gown (this includes all family members and visitors). When the patient leaves the room he/she must wear gloves and an isolation gown. If you're not entirely familiar with this practice I would suggest reading the AMA article which also outlines some more interventions to reduce transmission of a hospital acquired infection (clostridium difficile).

Overall, both articles are fascinating from an epidemiological standpoint: the first is how drastically hospitals have been able to cut their infection rates by aggressively implementing the CDCs guidelines for isolation practices. There are little things included that one may not initially think of, such as placing the trash can near the door so gloves/gowns are removed as the person is leaving. But it also gives other issues to consider. C Diff in particular affects people who are on antibiotics or proton pump inhibitors (PPIs). In an attempt to reduce post-surgical infections, new guidelines have resulted in an increase in antibiotics (antibiotic prophylaxis). So how do we balance the need to reduce post-surgical infections with the need to decrease rates of C diff? This will require further study and cost-benefit analysis to find a better balance.

The second article not only interests me from an epidemiological standpoint, but also in terms of connections with patients (and, I'll admit it, my own laziness). Basically this article looks at the impact of all the isolation precautions on the patients and the connection between the patients and caregivers. Because following isolation precautions involves added time to gown/glove, it is uncomfortable (the gowns are stifling hot), and it hinders a person's natural movement and makes working with the patient harder. Not to mention, the sticky tabs on the gowns pull hair, the gloves makes a person's hand sweaty, and it's nearly impossible to find a decent vein without at least one finger degloved.

This article states outright what I see every day at work: when patients are in isolation staff members purposely reduce contact with them by lumping work into one single trip, having only one person gown up, asking patients questions from the doorway instead of going in, and the patients themselves (if able to walk) avoid coming out at times. It also points out that patients in isolation have more non-infectious complications such as falls, pressure ulcers, depression, anxiety, and most shockingly "as much as a 100% increase in the overall incidence of adverse events." Wow, the very precautions we put in place to decrease particular adverse events actually increase other events.

I latched on to this quote from the article:

In two separate studies, researchers at the Medical College of Virginia in Richmond found that the rate of infection was identical whether health care workers wore gowns and gloves with only the patients in isolation or whether they wore only gloves with all patients.

 First of all, because I would be super psyched if I only had to wear gloves with isolation patients. Second, because of the interesting results of wearing gloves with all patients. Although it sounds benign enough, physical contact and touch is a big part of medicine and even the thin barrier of gloves greatly reduces what a clinician can actually feel and garner from touch. (for an interesting article from a physician's perspective regarding touch and the inner-conflict arising from gloves with all patients check this out)

It will be interesting to not what comes of this finding: those who work in healthcare would love to get rid of the frustration of isolation precautions, patients would love to get rid of the hassle of isolation, hospitals would probably enjoy the break the budget would get without buying isolation gowns. But I'm guessing that it will not be a quick change: we as humans naturally think that more protection (and more visible protection) is always better regardless of the evidence against it. (For example, did you know that the suds from dishsoap and toothpaste don't affect cleaning ability?)