Mr Epidemiology

No, I'm not a skin doctor



Going to #CPHA2014

The 2014 CPHA conference will be held in Toronto, ON | Picture courtesy Wikimedia

Next week, I (Atif) will be heading to the Canadian Public Health Association Conference, where I’ll be presenting at two different points.

I’ll be chairing a session titled “Youth Injury Prevention in Canada – Where should we direct our intervention resources.” It promises to be an interesting presentation, where we’ll be discussing injury in Canada, and where to start tackling the problem of injury. This session is scheduled for Wednesday, May 28th from 1:30pm – 3:00pm.

Injury represents one of the most important negative health outcomes experienced by young people in Canada today. Injuries inflict a large burden on children and adolescents and their
families and communities. Injury events are costly in so many ways, whether measured in premature mortality, or the pain, disability, lost productivity and emotional consequence of non-fatal events.

This panel will be made up of child injury researchers and advocates who will make their case for different forms of injury prevention intervention. At the end of this panel, delegates will: understand more about the burden of youth injury in Canada; be aware of at least four different avenues for injury prevention intervention (primordial intervention, context-level interventions, safe sport and peer-influence interventions); have identified the rationale, strengths and limitations of each intervention approach; and have learned more about ways to undertake and gain support for youth injury prevention (from the CPHA conference program).

Click to go to the conference website

My second presentation is one of the studies from my PhD, titled “The influence of location of birth and ethnicity on BMI among Canadian youth.” This is a study that’s in press (woo!), and represents my own research focus. This one will be in the Kenora Room, on Thursday May 29th 2014, from 11:00am to 12:30pm.

Body mass indices (BMI) of youth change when they immigrate to a new country. This occurs by the adoption of new behaviors and skills, a process called acculturation.

We investigated whether differences existed in BMI by location of birth (Canadian vs foreign born) across 7 ethnic groups, both individually and together. We also examined whether time since immigration and health behaviors explained any observed BMI differences.

Data sources were the Canadian Health Behaviour in School-Aged Children Study and the Canada Census of Population. Participants were youth in grades 6-10 (weighted n = 19,272). Sociodemographic characteristics, height, weight, and health behaviors were assessed by questionnaire. WHO growth references were used to determine BMI percentiles.

Foreign-born youth had lower BMI than peers born in Canada, a relationship that did not decrease with increased time since immigration. Similarly, East and South East Asian youth had lower BMI than Canadian host culture peers. Finally, Arab/West Asian and East Indian/South Asian youth born abroad had lower BMI than peers of the same ethnicity born in Canada. These differences remained after controlling for eating and physical activity behaviors.

Location of birth and ethnicity were associated with BMI among Canadian youth both independently and together.

Our findings stress the importance of considering both ethnicity and location of birth when designing and implementing interventions. While currently either one or the other is addressed, our study shows there is heterogeneity in BMI by specific ethnic groups depending on whether they were born in Canada or not.

As always I’ll be trying to livetweet the conference. I’ll be using the #CPHA2014 hashtag, so feel free to follow along online! As always, there are a wide range of presentations and workshops, so I’m excited to attend.

If you’re attending the conference, leave a comment with details of your own presentation so that other readers can attend your talks. And if you see me at the conference, be sure to say hi!

This was posted simultaneously on my blog PLOS Blogs Public Health Perspectives

Childhood obesity drops 40% in the last decade. Or not really, but who’s checking?

“A lie that is half-truth is the darkest of all lies.”
― Alfred Tennyson

Last week, a study published in the Journal of the American Medical Association looked at the prevalence of childhood obesity over the last 10 years. The study, performed by Cynthia Ogden and colleagues at the CDC, aimed to describe the prevalence of obesity in the US and look at changes between 2003 and 2012. The study itself had several interesting findings, not least among them that the prevalence of obesity seems to have stabilized in many segments of the US population. However, they made one observation that caught the media’s attention:

“There was a significant decrease in obesity among 2- to 5-year-old children (from 13.9% to 8.4%; P = .03)”

This is where things get interesting, as the focus was not on the 5.5 percentage points difference. Instead of reporting the absolute difference, i.e. how much something changed, news outlets focused on the relative difference, i.e. how much they changed compared to each other. In that case, it would be (5.5/13.9 =) 40%. Which is much more impressive than the 5.5% change reported in the study. So you can guess what the headlines loudly proclaimed.

Click here to continue reading!

The Biggest Public Health Stories of 2013

2013 was a big year for public health. We were thrust to the forefront again with disease outbreaks, and have had to deal with increased skepticism of the nature of what we do from the public. Meanwhile, within the establishment, rifts have been growing between groups, as different professional organizations vie for power and control. Here are my top five public health stories for 2013, presented in no particular order, but I’d love to hear yours in the comments.

1. Polio in Syria
Polio is a crippling disease that has been covered on the blog before. It’s been almost completely eradicated, but is still endemic to certain parts of the word. However, following civil unrest in Syria, polio has started to spread again and has, to date, crippled 17 children. Before the March 2011 uprising, vaccination rates were estimated to be above 90%. However, since then, estimates for vaccination rates hover around 68% – enough to prevent the benefits of herd immunity from kicking in. In order to increase immunization rates, the UN is trying to mobilize a vaccine drive. However, due to political and safety concerns, they are having a hard time ensuring that all children are vaccinated. To quote NPR:

Polio does not stop at borders or military checkpoints. Without a comprehensive response to stop the virus, aid workers fear that the outbreak could become a public health catastrophe.

Click here to continue reading!

On Men’s Health and Moustaches

Movember is one of, if not the biggest, charity aimed at raising awareness about men’s health (Click image for more)

In Canada, the top three causes of death for men are cancer (31.1%), heart disease (21.6%) and unintentional injuries (5.0%). The top two are the same for women, although with slightly different percentages: cancer and heart disease account for 28.5% and 19.7% of all deaths among women, with stroke (7.0%) coming in third. In the US, men die at an overall rate 1.4-times higher than women, of heart disease 1.6-times more, and are twice as likely to die from an unintentional injury.

In fact, women outlive men by 4.5 years on average worldwide – 66.5 years vs 71.0 years. This difference increase to 7 years in the developed world. Not only are men more likely to die from the causes above, men are also more likely to commit suicide than women. This gender difference increased following the recession. A time trend analysis from the UK found that approximately 850 more men, and 155 more women committed suicide than would have been expected based on historical trends following the 2008 economic downturn, with the highest increases in those regions that were most affected by rising unemployment.

But what leads to these outcomes? Given we live in a world where people can get help when they need it, why should men be dying at a rate that is that much higher than women for (almost) the same diseases? And why are they dying younger than women?

Click here to continue reading!

On giving constructive and helpful feedback

Last time I spoke about how to deal with negative feedback, and how you can cope with it. However, as you transition from undergrad, to graduate student, to senior graduate student (to life afterwards), you’ll be placed more and more into positions of responsibility. When that happens, it will be your responsibility to give feedback, and at this point, you realize that it’s really difficult to give good, constructive feedback that doesn’t come off as harsh.

Depending on the person, this feedback could be to a student, a colleague, or even a senior student. My research group has had a lot of success with practice run-throughs of presentations for conferences and defences, and once the person has presented, giving them useful and constructive comments is something we strive for. The easy route out is to give them “soft” feedback and avoid major problems. However, that doesn’t help them as, if you don’t point out major points they can work on, someone else will. The goal of this post is to help you frame that feedback.

And, in honour of Thor: The Dark World, coming out this week, I’ll be recruiting my good friend and gym buddy Chris Hemsworth* to help me with this post.


This just makes me laugh. I’m not even sure why.


1. Real life or email?
The first question is how to give feedback – face to face, or via e-mail. As we move more towards an electronic presence, sometimes it’s not only easier to give feedback electronically (such as when you’re in different cities), sometimes you have to (such as when you’re using track changes in word). People disagree over which is best, with this article falling on the email side, and this article falling on the face to face side. Frankly, I think both can be done well, and both can be done poorly. Finally, if you do choose to provide feedback in real life, keep it respectful, and, if necessary, private. Do not publicly shame someone.

A car is not a good place to give feedback.


2. Follow up
This relates to the point above, as one of the major benefits of face-to-face feedback is that you can provide instant feedback and clarify concerns on the spot. Email does not allow for quick clarification the way a face to face meeting does. One option is to send the email and then follow up on the phone or in-person soon afterwards, or meet first, and then provide written feedback. Similarly, once the feedback has been given, that’s not the end of the process. Improving oneself and developing skills takes time and effort, and small “course corrections” may be required, especially if the person has a hard time interpreting what you’re asking them to do. If they want more help or clarification later on, that should be available to them.

Don’t worry Thor, we’ll be specific!


3. Be specific
If you have an issue with something, say that. Don’t be vague as that can lead to further confusion. For example, some people when they present, never make eye contact. So when providing feedback, say “you need to make more eye contact.” Don’t say “you need to engage the audience.” The latter is not helpful, and can mean a number of different things, ranging from more eye contact, to more audience participation, to revamping your slide deck. Providing specific comments bypasses this concern.

We’re not attacking you Thor! We’re just providing feedback!


4. Present facts, not opinions
Avoid subjective words and emotional descriptions of events. Rather than saying “you didn’t care about this project” you want to focus on the specifics “your introduction needed more detail about X.” Continuing in the same vein, remove emotion and wait if things are too charged. Waiting for people to process their own feelings following an experience allows for everyone to think logically and productively, and at that point, feedback (may) be welcomed. This is as much for you as it is for them:

“The exception to this is if the situation involved is highly emotional. Here, wait until everyone has calmed down before you engage in feedback. You can’t risk letting yourself get worked up and risk saying something you will regret later.”


That is good, positive, specific feedback! Way to go Thor!

5. Positivity!
We often dwell on the negative, and only provide feedback about areas of improvement. However, also consider providing positive feedback! If someone does a really good job of explaining a concept, or writes a very clear article, then tell them that! One of the tricks is learning not only what you need to improve, but capitalizing on what you do well and putting that front and centre, and stating that can help boost a person’s morale, confidence and make the whole process a lot more enjoyable and positive for all involved.


Further reading:
View story at


This was published simultaneously on Gradifying

*Note: I’m not actually friends with Chris Hemsworth, and I’m not getting anything from Marvel Studios/Walt Disney Studios Motion Pictures to include these GIFs.

Book Review: Deadly Outbreaks: How Medical Detectives Save Lives Threatened by Killer Pandemics, Exotic Viruses, and Drug-Resistant Parasites

Deadly Outbreaks: How Medical Detectives Save Lives Threatened by Killer Pandemics, Exotic Viruses, and Drug-Resistant Parasites | Click image to go to CSTE website

Anyone who follows my writing knows that I’m a big proponent of using stories to talk about science. We’ve discussed how you can use science fiction teach science, zombies to talk about disease outbreaks, and my TEDx talk discussed using principles of storytelling in how we discuss science. So when I was asked to review (see disclaimer below) Dr Alexandra Levitt’s new book “Deadly Outbreaks: How Medical Detectives Save Lives Threatened by Killer Pandemics, Exotic Viruses and Drug-Resistant Parasites,” I jumped on the opportunity.

The CDC has a program known as the Epidemiologic Intelligence Services, where individuals trained in fields such as epidemiology, medicine, statistics and veterinary sciences come together to identify causes of diseases. For an overview of the EIS, check out this review of “Inside the Outbreaks” by Travis Saunders over at Obesity Panacea. The EIS was set up Alexander Langmuir, who has been profiled on the blog, and their work has been instrumental in learning about, and thus containing, disease outbreaks all over the world. Dr Levitt is well positioned to speak on these issues, having worked at the CDC since 1995, although it should be noted that this was written in her free time, not as part of her position at the CDC.

To continue reading, click here!

Dealing with negative feedback

You know the feeling.

You’ve spent the last month working on a manuscript/paper, have fleshed out your ideas, spent countless late nights editing and making things sound *just* right, and you’ve finally sent it in to your supervisor. This will be the draft. This will be the one that they read and go “Wow! Good job! Submit this to Nature immediately!” And it’ll be accepted within a week, and you’ll be flown to Washington to present the paper to President Barack Obama himself, and, while you’re there, BB King will show up and you’ll jam together in the oval office, and, just when you think you’re about to finish your Epic Blues Jam Session, Bill Clinton will come by and play the saxophone.

But then, your supervisor sends you your paper back, and it’s either covered in red ink or there are 714 comments in Microsoft’s Track Changes.

This is *literally* the most appropriate GIF I could find.

One of the major reasons you’re in grad school is to learn from these experiences. There is a reason your supervisor is the Canada Research Chair of Awesomeness, or is internationally known for their work. It’s because they’re very good at what they do, and part of what they do is write, and write well. Your goal is to learn everything you can from them, and in that process, improve your skills. And writing is just one part of this process – your ideas will need refinement, your writing will need work, your teaching will need improvement, all of these are skills you can work on during your graduate education. However, in order to improve, you need to deal with feedback, which can come from a wide range of sources including your supervisor, your students (via TA/TF evaluations) and people at conferences.

1: Take a break.
The first thing I tell all the students I work with when they get back corrections is to read it, then leave it. Skim over the comments, get that initial “THIS IS THE WORST NEWS EVAR!” feeling out, and then go for a walk. Once that initial visceral response has passed, you can start dealing with the comments themselves. As this 99u article says:

Don’t react defensively – or aggressively – no matter how hurt, disappointed, or annoyed you feel. Start by taking a deep breath and reminding yourself of your goal.

2: Remove emotion from the equation.
As silly as it sounds, you do get emotionally attached to your writing over time. You’ve spent countless hours tweaking everything, making it sound *just right* before sending it in. You’ve read and reread sentences again and again to make sure they’re clear. Your supervisor then rewrites many of those sentences, and may suggest that some are unclear and need work. At a conference, someone might be less diplomatic, and call your work all kinds of names. You need to take emotion out of the equation as you hear those comments, and decide what comments have merit and require further thought. One thing you should not do is take criticism of you to be a personal attack. Negative feedback isn’t personal. By removing any emotional responses from the comments, you can evaluate comments on their own merit, and decide how to deal with them.

This may be extreme, but you get the idea.

3: Triage comments
In an emergency room, patients are triaged. Those with life-threatening conditions are identified as high priorities, while those who do not need immediate attention will be waiting for beds to open up. Similarly, you need to identify which comments are important, and need to be addressed immediately, and which are stylistic and you can let slide. Pick your battles.

4: Identify constructive criticism
We’re now thinking of comments outside of those that your supervisor would give you – we’re into the realm of feedback from students, audience members at presentations, and others. Listen to the comments, and understand why the feedback is being given and what you can do to improve. What you really need to do here is identify what is constructive and helpful, and where the comment is coming from so you know how to fix it. Use the comments to help you, and be objective about whether or not it is useful – even if you don’t like the comment.

5: Ignore personal attacks
One of the best pieces of advice I got as a Masters student was to listen to all comments and evaluate them all, even the ones you don’t agree with, but to always ignore personal attacks. And you will get personal attacks – students will write mean comments in TA evaluations, people will attack you at conferences, and, especially if you put your ideas out on the internet, you will get called all kinds of names. It’s very easy to dwell on those comments: don’t. You know you’re good at what you do, and don’t let anyone tell you otherwise.

This GIF always makes me laugh. I don’t know why.

6: Don’t listen to everyone
And thus we get to the final point: don’t listen to everyone. Everyone will have advice, everyone will have an opinion. Take the points that you like, synthesize them, and use your own judgement to decide what works for you and fits your project/worldview (that includes this article). Don’t accept everything blindly. Decide what you stand for, and if someone is arguing with you about it, plant your feet firmly and don’t budge.

This was originally published on Gradifying.

Sabremetrics and Math: How sports can teach statistics



Mental arithmatic.

Do those words scare you? If they do, you’re in good company. Mathematical anxiety is a well studied phenomenon that manifests for a number of different reasons. It’s an issue I’ve talked about before at length, and something that frustrates me no end. In my opinion though, one of the biggest culprits behind this is how math alienates people. Lets try an example:

If the average of three distinct positive integers is 22, what is the largest possible value of these three integers?
A: 64
B: 63
C: 33
D: 42
E: 48

Too easy? How about this one:

The average of the integers 24, 6, 12, x and y is 11. What is the value of the sum x + y?

A: 11
B: 17
C: 13
D: 15

I do statistics regularly, and I find these tricky. Not because the underlying math is hard, or that they’re fundamentally “difficult,” but because you have to read the question 3 or 4 times just to figure out what they’re asking. This is exacerbated at higher levels, where you need to first understand the problem, and then understand the math.*

Last week, my colleague Cristina Russo discussed how sports can be used to teach biology. Today I’m going to discuss a personal example, and how I use sports to explain statistics.

One of my main objectives as a statistics instructor is to take “fear” out of the equation (math joke!), and make my students comfortable with the underlying mathematical concepts. I’m not looking for everyone to become a statistician, but I do want them to be able to understand statistics in everyday life. Once they have mastered the underlying concepts, we can then apply them to new and novel situations. Given most of my students are athletically minded or have a basic understanding of sports, this is a logical and reasonable place to start.

Click here to continue reading!

Featured Interview with the Queen’s University School of Graduate Studies

Friend of the blog Sharday Mosurinjohn recently interviewed me for a profile on the Queen’s University School of Graduate Studies website. The first paragraph of her (very flattering) interview is below, and follow the link provided for the whole thing.

Atif Kukaswadia – AKA Mr. Epidemiology – is here to help you understand the science that’s important to your life. As a PhD candidate in Queen’s Department of Public Health Sciences and a science writer for the Public Library of Science (PLOS) blogs network, Kukaswadia is immersed in creating and reporting on scientific knowledge of direct relevance to the public, and he wants to share the wealth.

Kukaswadia moved to Canada in 2002 with his family from the UK. He started his undergraduate degree in Biology at Carleton University, where he focused on ecology and studied caterpillars, butterflies and mud shrimp. The thing Kukaswadia most enjoyed about ecology was how “everything was interconnected – you never study one squirrel in isolation. You study the whole environment and how elements of the environment interact.”

While he enjoyed Ecology, he realized that studying butterflies and caterpillars wasn’t for him. So he started a second degree in Health Psychology. Using his background in ecology, he began looking at humans the same way he had been trained to look at non-human animals and, specifically, at how the environment affects humans. This combination of interests led him to Queen’s, and the Department of Public Health Sciences.

Click here to continue reading!

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