So what exactly is a risk factor, anyway?

We epidemiologists are pretty darn picky about the words we use, how we use them, and what they mean (why else could we have so many different types of incidence measures)? Sometimes nuances in phrasing are harmless, like, whether we call a sport cycling, bicycling or biking (unless you say that to a cyclist who takes themself very seriously). Other times, what seems like nuance can mean a world of difference.

When talking about measures of likelihood, it’s possible to conflate risk and odds. There are specific situations where these numbers approximate one another, but if you don’t know the difference between these and what those situations are, you can run into problems, such as severely biasing your results. If you’re talking about how chewy your apple pie is, a biased answer is probably unproblematic. If you’re interpreting results from a research study, that’s not the case. So now that I’ve established a reason for being picky, let’s go through an example.

Risk factors, correlates, covariates, predictors, causes, lions, tigers, and bears – oh wait, nevermind. But let’s dig deeper and clarify what it means to distinguish between these.  Risk factor. A commonly used, but vague term (I’ve already used it many times in my dissertation). According to the World Health Organization, a risk factor is “any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury.” But does that mean that a risk factor is a potential cause? Not necessarily.


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I think it’s worth taking a step back to think about context. Why even ask about risk factors in health science? From a public health standpoint, I argue that we ask about risk factors that we can intervene and hopefully prevent future cases. As Yogi Berra once said, “it’s difficult to make predictions, especially about the future.” So since we can’t actually predict the future and most of our methods of data analysis tell us about averages in groups, we can find out which characteristics, on average, are associated with higher probabilities of the outcome of interest. Without boring you with jargon, one of the ways we do this is through statistical adjustment (simply put: controlling for the impacts of other competing explanations) in regression. In exploratory studies, this is one way that risk factors are identified. When there could be confounding, one could include the variable as a covariate in the model to account for that competing explanation. A covariate could be also a risk factor, or another potential cause.  A covariate could be some other thing that’s associated with your outcome that isn’t a potential cause.

Think about a time someone went through a list of potential factors with you, like this list of risk factors for a stroke. A quick look at information from the Mayo Clinic lists a number of risk factors for diabetes. The risk factors for Type 2 diabetes include: weight, physical inactivity, a family history, race, age, gestational diabetes, polycystic ovary syndrome, high blood pressure, and abnormal cholesterol and triglyceride levels. Some of these risk factors could be causes, some of theses could be correlates, and some of these could be other health conditions due to the same causes.

If you examine other health behaviors and conditions, you’ll likely see a similar variety of types of risk factors. But it leads me to a question: Is it worth calling something a “risk factor” if it’s not a potential cause?

In my dissertation, I’m studying child maltreatment. Specifically, I’m studying whether people who experience maltreatment in their childhood are more likely than other people to maltreat their own children when they become adults. This is also called intergenerational child maltreatment, continuity of child maltreatment, and more broadly cyclical violence or adversity. This is a commonly held belief, but the research out there is inconclusive, and there’s much to be studied. One of the aims in my research, is testing for differences in the frequency of intergenerational maltreatment between groups. While there’s a lot of scientific theory (and pop psychology) out there about the causes of violence, it’s not easy to name a specific cause. Some known risk factors for perpetrating child maltreatment include: interpersonal violence, substance abuse, and there are known disparities in CPS contact between racial and ethnic groups.

Are all of these groups risk factors? Are some of them covariates? And what exactly is the difference between a risk factor and a covariate? I honestly don’t know. It could be useful to know potential causes so that eventually preventing the outcome is possible. But aren’t non-causal risk factors useful in their own right? 

Do risk factors have to be something a person’s choice? I might choose to bike without a helmet, knowing it increases my risk of a traumatic brain injury if I end up in a crash. But biking on streets without bicycling infrastructure is associated with higher risk of crashes (and subsequently, higher risk for traumatic brain injury, see here and here). Most of us don’t choose how streets are designed. And those not living in bike-friendly cities can’t always find a bicycle boulevard.  It’s a complicated conversation to talk about distributions of risk among things people don’t choose.

If a risk factor is changeable or preventable (like substance abuse, to the extent that it is preventable), wouldn’t we want to help people prevent that? We can’t prevent people’s race or gender (at least not in a world that I want to live in). We can’t prevent people’s family history (without superpowers). It would be a tall argument to say that someone’s demographic composition is a cause of their illness or health behavior. But it’s still useful to know these risk factors, especially if it means you can provide resources to groups at greater risk and prevent.

All of this discussion leads me to questions I’ve been wrestling with for a long while: if we can’t predict the future, but knowing something increases risk allows us to prevent an adverse outcome, does it matter if the risk factor is a cause? If something puts you at increased risk, is that enough information? And what amount of increased risk is necessary for action?

Supraspinatus... Super Spin ate us?

Who’s Super Spin? What are they eating? And why am I talking about this weird hungry superhero/villain? Are they a spinning top with razor blades coming out of the sides?


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Uhhhh, no. I’m actually not. I’m talking about the supraspinatus, one of the muscles in the rotator cuff, muscles that help keep the head of the humerus (upper arm bone) in the glenoid cavity of the scapula (simply put, the shoulder socket).


And I’m talking about it because a couple of months ago I injured mine. As I was going down a set of stairs, I slipped, and holding onto the rail, my arm went into a funky position, bearing the weight of my body. I went about my workout as normal, but the next time I practiced yoga, I felt a suspicious pinching feeling in my shoulder and felt pain when I raised my arm out to the side.

I decided to wait a few weeks before investigating further, hoping it was just minor muscle irritation. It turned out that, after seeing a sports medicine physician and physical therapist, that I had irritated the tendon of the supraspinatus, which would require a course of physical therapy, minimizing strain on it, doing exercises to strengthen the rotator cuff muscles, and refreshing my knowledge of biomechanics. It also, as a yoga teacher, has meant that demonstrating or practicing a number of postures such as side plank, crow, or chaturanga dandasana (high to low plank) is out of the question. As much as I love doing it, bad form can strain the tendon further and I’m not willing to take the chance that one bad chat will prolong my recovery.

Injuries happen in and out of yoga practice, and I have had plenty before, both in and out of yoga. I think it’s important to be transparent about mine. Attending classes with an injury in my shoulder (something I’ve never done before) has been challenging. Not being able to do things with my body that I’ve worked hard to be able to do has been humbling. Having to, with each new instructor, tell them about my injury and be a student in class who can’t do things has been humbling. It’s also given me gratitude for the things that I can do, and new awareness of how many times the standard vinyasa flow class bears weight on the shoulders

In no way am I saying these poses are bad or that I’ve come to some enlightenment that because I can’t do something, I need to tell the rest of the yoga community to stop doing it. Hardly. There are a lot of potential benefits from building strength in the arms and shoulders. But if I wasn’t aware that, as a teacher, it’s important to vary the parts of the body doing the efforts throughout class, this experience has really brought it on home. Just as much, I wouldn’t want a student with a knee injury to be excluded because kneeling postures were the theme of the day.

It’s also taught me something valuable in my own practice, that’s really relevant to life. Sometimes things simply aren’t for you; either for a moment, or for a long period of time. For example, at my wellest, I don’t have the mobility or bone proportions to bring my elbow outside my thighs in a twist, so side crow isn’t a posture available to me. For the time being, if I want to get better in my shoulder, substantial amounts of weight-bearing postures in the shoulder aren’t available to me. Does that mean it’s time to hang up my mat and quit doing yoga? Fuck no! It means I continue to show up, even when it’s hard.

This practice is about so much more than doing the postures; in fact, the postures aren’t the point. As of my teachers has said, it’s a really advanced practice to choose not to do a posture. Sometimes it’s available to us, but it wouldn’t be wise to do it for a number of reasons. Sometimes it’s not available and we strain hoping to find enlightenment on the other side of putting your body in a certain shape. But moving your body in a certain way only gets you closer to being awake if you pay attention and stay present while you’re doing it. Otherwise, standing on one foot only makes you good at standing on one foot. So I ask you, how can you let this practice be more about learning to be well in your body than striving to get your foot behind your head because teacher said so? And what would it look like to choose your efforts based on what is a wise idea?

Mythbusting New Years Resolutions


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It’s almost New Year’s Day. So happy almost 2017! And with a new year, come the New Year’s resolutions. Calls for a new you, as if the old you is somehow flawed (I assure you likely not, at least not in any way everyone else isn’t too, but I digress). I am the kind of person who likes to make decisions based on the best available evidence. But with New Years resolutions and changing habits, there’s less science in the conversation than there is schmience. I wanted to make the evidence easier to find in this post.

What does science say about New Year’s resolutions? According to recent research, between 40 and 50 percent of Americans make New Year’s resolutions. Anywhere from 80 percent to 92 percent of those who so make resolutions fail to keep them for longer than a few months. Most of our resolutions revolve around self-improvement of some kind or another. A recent Nielsen survey found that fitness resolutions are the most common kind. Another common thread in resolutions are myths about changing habits. These are all myths I own that I’ve both held and tried on for size (hint: I failed, and then learned).

Myth 1. I’ll change everything all at once. I’m going to eat less, move more, save money, and be more productive at work.

Well, maybe. Maybe not. It’s commonly held that we should change one thing at a time. A recent study found great results in a multifaceted lifestyle intervention. It was one study, though, of 30 college students, that compared this strategy to a waitlist and didn’t measure how long habits changed. So the jury is out whether it’s better to change one thing at a time or everything at once. And it’s likely situational.

Regardless, it’s probably better to focus on changes that can be sustained, and to get specific with the goals. A recent study from Dominican University found that when goals are specific, written, and there is accountability they are more likely to be achieved.  One psychologist has said don’t try a habit unless you want it permanently. So no matter what you decide to change, if anything, think about what the actual goal is, and find a plan that works for your situation.

Myth 2. My gym/yoga studio/tabloid magazine/BFF told me about a great new 30 day challenge. I’m going to do it and then it’ll stick forever.

The ubiquitous 30-day challenge. Burpees, running, yoga, vegan, etc. If you can Google it, there’s probably a 30-day challenge for it. Why 30 days? It’s a number people can stick with? It’s a realistic time frame? It’s even? Everyone else is doing it? It’s 9 more days than the actual magic number, which is 21 days to start a new habit. Everyone says it so it must be true.

Uhh no. That number doesn’t come from any research on habits. That number is a quote from a plastic surgeon-cum-psychologist named Maxwell Maltz in his 1960 book Psycho Cybernetics about the number of days it takes patients to adjust to their new body. Does your vegannaise from that 30-day challenge sound and taste like plastic surgery? I didn’t think so. Or maybe it does, what do I know? University College London’s Health Chatter blog wrote a great piece about this in depth. I’ll let them say it for me. The 21 day number becoming widespread, in my opinion, has been people doing their best with limited information. But we can do better.

The biggest study to date (analysis of 82 people) found that the average number of days for making a new habit was more like 66, and it varied a lot, ranging from 18 to 254 days.

Yes, a 30 day challenge can be fun,  can be a great way to reconnect with old pasttimes or try something new. But I don’t recommend going in thinking there’s evidence that your fantabulous 30-day challenge will make the habit stick. If it does, it will have more to do with you than the number of days you did it.

Myth 3. This is the perfect time of year to change my habits.

When it’s dark early and late, cold outside many places on the Northern hemisphere, everything in you likely wants to rest, and you’re still in the midst of the food-based holiday gridlock? Winter is a challenging time.

And no matter when you do decide to, how will you address the reality that you’re a human, and as a human you might (and likely will, and likely should) fall off the idealized wagon of what you have? You might eat pizza again. You might stay up past 10 PM. Bacon is really f*cking hard to give up. 

Can you set your goals in a way that will acknowledge that possibility, and give yourself permission to slip up? Relapse is a thing; it’s a part of why, as mentioned before, most people who make resolutions don’t stick with them. Going back to the new habit after a slip-up is a big part of the work. This piece from the National Institutes of Health has a great discussion of stages of change in health behaviors.

Myth 4: There’s a magic formula to change habits.

Sadly, there’s not. Charles Duhigg, author of The Power of Habit, points out that there are thousands of formulae that depend on the person, the habit, and the situation. He wrote a great post about the steps on this post on his website and his interview on NPR goes into great depth on the topic.

Myth 5: I need to change.

We all change. Whether we change in ways we want to is another thing. But with all the talk of transformation out there, this is a time for you to collect your own data. Is your resolution based on an idea that there’s something that you’re lacking? Where is the idea that you should make a resolution coming from? Are you being sold that you need a “new you” with the New Year because someone told you that? Is the messaging of the resolution that you’re not enough? Remember that people and industries profit from New Year’s resolutions and it costs you, too.

In no way am I saying resolutions are doomed, bad, not worth making or not worth doing. I know people who’ve made dramatic changes because they made New Year’s resolutions. They’re the exception, though. Regardless, go forth with your resolutions, I wish you success in your endeavors. But more than that, I wish you informed decisions.

The Prisoner’s Dilemma, Political News and You

In the field of game theory, there’s something called the Prisoner’s Dilemma. Let’s imagine that two friends, Joanne Red and Keith Blue, were arrested and imprisoned for being suspects for a crime, but the police don’t have enough evidence to convict them. Keith and Joanne are separated and cannot speak to each other. The guard wants to know who committed the crime, and makes a deal with each of them. If they testify against the other, they get out free and get some money. Their other choices, then, are to stay in prison, or come forward for it, which spares their friend, but lands them in prison.

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Recent studies have pointed out how different our feeds are on Facebook, in particular, based on our political views, likes, friends, etc. The Wall Street Journal did a great visualization side-by-side about how people get different information about the same topic. What’s more, people are even receiving tailored ads from politicians based on their ads for what’s important to them. Kathryn O’Neill describes this in awesome detail in her book Weapons of Math Destruction. And if that’s not enough, partisan news sites, both left and right, give us very different      information, too. Combine that with fake news, anti-intellectualism, debunked myths being sold as facts, and a response from scientists assuming that the facts alone will speak for themselves, it’s no wonder things are divided and people are having a hard time communicating. It’s almost like we’re prisoners in this prisoner’s dilemma, and the selling out was our vote. We live in the cells of our informational bubbles, every time we assume the other group is just the worst and post or click as such, we “sell them out” and are rewarded with more information that confirms our beliefs.

There are a couple of things in this scenario that make things different from the Prisoner’s Dilemma. First, we aren’t actually prisoners. We can choose to “walk out” of our cells by adding variety to the information we consume. Joanne and Keith can talk to each other. A question, though, is whether Joanne and Keith can communicate.

In a culture of memes, buzzwords, catch phrases and viral videos, it’s likely that data alone will only persuade people who are persuaded by data. If left and right are ever going to have a meaningful, intelligent conversation, it’s going to take some serious work. The problem, as I see it, isn’t just that Joanne and Keith have different opinions about the same information. They have different opinions about DIFFERENT information, and likely have no idea what information the other consumed. This puts a burden on both of them to have to discuss not just the differences in opinion, but the differences in information that led to those differences in opinion.

What is that likely to require? It’s likely to require a lot of patience, for one. It’s also going to require openness to discussion. It’s going to require valuing the other’s perspective, even if there isn’t agreement. It’s going to require a clear, persuasive, and compassionate explanation of WHY the other is wrong. It’s going to require the willingness to be wrong. But most important, it’s going to require invitation back into the circle for those who were wrong, on those issues where there is a wrong and right.

In no way am I advocating for ignoring the rampant prejudice, hate and bigotry that is going on here. And in no way am I advocating that every Keith and every Joanne need to talk. But for those who are open to it and who can, I think it’s important to remember how much is required to get to the point where we can even have a conversation. Can you let the other person explain why? Can you point out the holes in their reasoning? And can you defend your arguments? Here’s a great guide about how to have these debates online. A lot of this is relevant to conversations in person, too.

The difference between Keith and Joanne and you and your coworker, family member, sports team member, is that I made Keith and Joanne up to make a point. You have to live with (or without) them. If we as a country are ever going to have meaningful discourse, I believe it’s a big part of what we need. Or we can stay in the respective cells of our information bubbles. Because that’s working so well.  

How I aspire to live the niyamas

One day at a time. I try to live this way rather than set a specific time to practice each. But I do find it useful to revisit and bring attention to them.

But broadly…

Saucha - I think of this as purity in my thoughts and mind, as trying to purify the body leads to realizing it’s not pure. It can’t be. It’s matter. It is what it is. So no detox for me. Others have written that and it’s been my experience that it leads to a lack of regard for the physical as ultimate and a preference for purity in presence. And as it were in actions, my karmas.


Right now it’s like this, as one of my teachers says. How can I be with what is and find contentment? It’s not accepting things complacently or not wanting things to be better, but that things are what they are, and I can’t change what is. Even when it sucks, where is there contentment. Sometimes this leads me to gratitude.

Tapas -

I make it a point to get out of my habits. Sometimes that means adding metaphorical fire to my practice by going heavy and hard in strength. Sometimes it’s challenging myself to dial back when I usually would go deep. It’s the thing that keeps me going. When I trained for triathlons, distance running races, doing grad school, the consistency of showing up is my practice of tapas.

Svadhyaya -
Even after YTT i continue to read texts, including groups like this for discussion. I continue to study the body, and I often use my asana practice as a chance to witness my own experience to the physical practice of asana.

Isvara Pranidhana -

I’m an atheist, so my Isvara is likely different than that of Patanjali. But I do surrender, my efforts aren’t just for me. This practice isn’t just for sculpting my butt. My calm mind isn’t to make my boss more money. My efforts aren’t mine, I serve. And that’s because I know it’s not all about me. I’m one human of billions, in a planet of billions of species, in a galaxy bigger than I can imagine, in a universe more expansive than I can comprehend. What I perceive is only a small part of matter interpreted by my senses so that I can exist and make sense. Yet everything is interconnected. We are all connected. And it’s that interconnectedness that I surrender to. I can’t control it all, so right back to what my teacher has said, right now it’s like this. Why fight it?