The general principle for stocking up, as far as I see it, is that any food you buy has to be consumable in it’s current state – i.e. without heating or refrigerating. Even if it would taste better hot or cold, at least it should be edible as is. So with that in mind, I suggest:

• Canned meats – tuna is popular and the grocery store was almost out of it, but you should also consider corned beef, spam, canned salmon, vienna sausages, deviled ham, etc. They may not be fancy, but they’re edible cold, straight out of the can and that’s what counts.
• Nuts – surprisingly, this section of the grocery store was largely untouched. Why? No idea. Nuts are tasty and high in energy. Stock up on all your favorites.
• Canned vegetables – again, this section of the grocery store was pristine, and yet people were buy fresh produce. That’s just silly – that big bag of lettuce your buying wont last if the power goes out, but you can eat canned potatoes, peas or carrots straight from the can and they’ll keep for, well, ever?
• Canned fruit, or fruit sauce – again, this seemed like the natural go-to section for me, but people were instead buying fresh fruit.
• Granola bars, cookies, crackers, potato chips – I was pretty shocked to see that people weren’t stocking up on these. Sure, they aren’t a meal, but they keep, they’re tasty which will lift your spirits a bit, and they’re pretty high energy. Indulge a bit.
• Jerky – processed so that it keeps without refrigeration. Sure many brands are pretty high in sodium, but you’re not eating it forever, just until the power comes back.
• Baked beans, canned – not great without heating, but edible and full of energy.

Things to skip or buy in small amounts:

• Pasta and rice – most online lists I saw were pretty heavy on these, which is fine if you’ve got power. Rice and beans or pasta and beans is a healthy, energy heavy meal that will keep you full and ready to face the hurricane clean-up. But if you don’t have power, these might as well be sandbags.
• Beans – canned baked beans not withstanding, most beans are not so good straight from the can without heating. You could probably get buy with eating red beans from the can, and refried beans are fine, but you’ll probably get gassy… just saying.
• Canned soup – now, I don’t know about you, but unheated canned soup just seems so unappealing to me. I’d skip this and get some more nuts instead.
• Water – okay, I know what you’re saying – “I need water!” – well, of course you do. But you don’t need to spend $50 on water – there’s this little thing I like to call “the tap” and water comes out of it for free. And now, before the storm, that water is probably fine to drink (obviously if it’s not, you should buy water but you probably do that already so you probably don’t need to stock up). So grab up all your tupperware, all your used soda bottles, water bottles, thermoses, anything with a lid, and fill them from the tap. You can store some in the fridge and some in the freezer. While you’re at it, don’t forget to fill your mop bucket or bathtub with water so that you have something to flush the toilet with if the water main breaks. You’ll thank me later.

So, that’s my 2-cents. What tips have you come up with for preparing for hurricanes, or other storms?

In the post on power analysis, the main problem wasn’t really the quality of the data (although I could say a thing or two about that) but rather the somewhat atypical analysis we were hoping to do. Since that post, I’ve had the opportunity to work with several non-research oriented groups hoping to analyze data collected for administrative purposes. If you don’t think why the data is collected makes a difference, then let me warn you – you’re in for a shock.

Administrative data can be really good, especially when the administration realizes in advance that this data will be useful for research or decision making in the future. Best case scenario, the data is clean and broad. What this means is that the dataset contains a number of different measures that all get at the same basic question, that there is very little missing data, and that the data all makes sense conceptually. Worst case scenario, none of that is true.

But more typically, what you do have is a fairly complete dataset (it is needed for administrative purposes after all, so for example if it’s payroll data everyone will probably have job hours worked). The real problems are awkward measures and what I like to call ‘crazy data’ – data points that just don’t make sense, categorical variables that are so contradictory or over-generalized that they’re useless, or coding options that are basically bizarre.

For example, you might have hospital discharge data with a variable called ‘birth weight’ which should only apply to newborn infants and be missing for all other patients, but for some reason is coded as ’0′ for both still-born infants and for all children and adults. Why did someone make a decision like that? Because they don’t plan on using that variable in the ways a researcher might.

Alternately, you might have a variable called ‘duration of short-term work absence’, where short-term is defined as 6 months or less. When you go to split that variable into categories, you discover a whole sub-group of people with so-called “short-term” absences of 6-12 months. What’s going on? More than likely, data you thought was continuous is actually cumulative, so this group of people had 2 or more absences of less than 6 months each. But there’s no way to know for sure unless you can get ahold of someone in charge of the dataset, which isn’t always easy or possible. Frustrating!

And then there’s the problem of sub-optimal measures. For instance, you might want to investigate the rate of injury among hospital employees. Well, for a rate, you’ll need a denominator. The most obvious denominator would be the total number of employees – usually researchers try to use full-time equivalents, which is a way of adjusting for part-time and casual workers. But what if the only data your hospital can provide is the number of beds or patients at any given time? What’s that you ask? Why don’t they know how many employees (or employee-equivalents) they have? Sigh. I wish I knew. But it’s more common than you’d think.

The final problem I’ve come across with administrative data is the question of format. Since administrative data is often used for billing or payroll within a single organization, it’s often inputted in whatever software the billing or payroll people in that organization are most comfortable with. You might get lucky and find that they can provide it in Excel or even a .csv file, but chances are that’s not going to be the case. I’ve had situations where I’ve had to manually enter the numbers in a spreadsheet from pdf tables, or even pull data from text-based case-descriptions (fairly common with surveillance data).

Overall, my biggest lesson has been in terms of budgeting time for preparatory research activities. When you’re in class, it seems like the hardest part of research should be setting up the experiment or observational study and collecting the data. Analysis should be a breeze!

And maybe that’s true if you’re in a position to design the whole project from scratch – it certainly was true when I worked in Biology labs – but if you’re not doing the data collection, watch out! So far, my experience has been that it takes 4-6 months to really be sure that your administrative dataset is clean, sensible, and that you understand what all the variables are, what the limitations of the dataset are, and what the best method for analyzing the data you have is.

Have you had any frustrating experiences with “real world” datasets you’d like to share?

Confession, I’m kind of a lazy person – I’m a workaholic and a bookworm. So the idea of exercise used to make me feel like curling up with a good book. But in the last 4 months, I’ve gone from not being able to run for 5 minutes straight to running 20km a week. And I feel pretty darn proud of myself for making that change. I owe it mostly to a really great running program from the University of British Columbia called Learn to Run 10k, which you can find here (pdf warning). If you’re trying to learn how to run, I’d really recommend it because each day’s run really does build on the previous run and the increases in difficulty are never too big.

The next step on my goal to a healthier life is eating right. When I was a kid, we used to eat mostly vegetables with just a little meat and it was great. But once I moved out on my own, eating like that became a real challenge. When you’re only cooking for one (or two now), it seems like far to much work to make the three or four dishes per meal that my mum used to do for a family of five.  I can usually manage some rice and meat, but that’s about it.

I also keep running into the problem of what vegetables to cook – when it comes time to make dinner, all I can ever think of is carrots, celery, tomatoes and lettuce. Not exactly an exciting mix. Tasty, sure, but kind of repetitive. Anyway, I’ve been trying for a while to experiment with new vegetables every couple weeks.

To encourage me, and to help me keep track of it all, I’ve set up another blog for that. If you’re interested or have any ideas for what I could try, check out Finish Your Veggies!.

And tomorrow, I promise I’ll post an Epi post!

Wish me luck

I know this is a highly contentious topic for many people. I don’t pretend to be an expert on vaccines, and I’m certainly not a virologist, but I do have training and experience in interpreting biological and epidemiological data about infectious disease.

So with those caveats, I’d like to discuss importance of measles vaccination and the real life life and death consequences of vaccine refusal.

First of all, what is measles? Simply put, it’s a virus and a disease caused by that virus, with a rash, fever and cough as the main symptoms. One identifying feature of the measles rash is that it starts on the face and then spreads to the rest of the body. Although children are most likely to get measles, adults can get sick and, like with chickenpox, often have a more serious illness.

Once you get measles, there’s no specific treatment and you can spread infection before you even show symptoms. In fact, measles is one of the most highly contagious human diseases. In 2008, 164,000 people died from measles, most of them babies under the age of 5. Kids who are malnourished are especially at risk for complications, like blindness, or death. Even in high-income countries, measles can be a serious disease – one in 1000 people will get encephalitis (a brain infection that can cause deafness or mental disability), and 1 in 3000 may die.

Okay, but why should you care? Besides the fact that thousands of people die each year – 18 every hour – measles is making a comeback worldwide, and especially in high-income countries. In 2003, it looked like measles had been wiped out in the Americas, because by June of that year not one single case of measles had been detected. Parents started to become complacent, and for many people concerns about the vaccine started to outweigh concerns about measles. But, just because measles isn’t transmitting somewhere, doesn’t mean it can’t show up. And this is just what it has done.

In the first six months of 2008, there were 131 cases of measles across 15 US states; while in early 2010, 82 cases occurred in British Columbia, Canada, alone. Both outbreaks have been linked international travel. In the United Kingdom, too, measles is now circulating regularly in the population, despite having been wiped out in the mid-1990s.

What can we do? Measles is a disease of people, and is highly contagious. So long as one person has measles, everyone everywhere has the potential to get measles. But there’s a very effective vaccine – two doses effectively guarantee that you will never get measles, and costs less than 1 dollar (US and, approximately, CAN) for each dose.

Okay, but is the vaccine safe? Whenever a vaccine is given in the US, the doctor is required by law to report any problems or symptoms that follow to the CDC. Based on this reporting, we know that up to 15% of people who get the vaccine will get a fever, typically only following the first dose; approximately 5% of people will get a rash. More serious complications have been reported, including encephalitis, but these occur less than once for every million vaccine doses given – less frequently than the general, non-vaccine related occurrence – which suggests that these were coincidences rather than effects of getting vaccinated.

Not convinced? That’s fine. It’s not my place to convince you that you should vaccinate yourself or your kid. But I do want to convince you that measles is a problem – one that can be solved. Maybe you don’t think that the risk to your child, or yourself, of getting measles is very high. Maybe you even think it’s less than 1 in a million – in that case, the vaccine might actually be a bigger risk.

But there are millions of children who are at real risk of getting, and dying from, measles. And two dollars from you could keep them alive.

Something to think about.

GIDEON-Online has an e-book describing all the infectious diseases in Haiti, which it is providing free for download to anyone working to provide disaster relief or medical care in Haiti.

If that’s you, and you haven’t seen this book yet, go check it out: here.

Anthrax is a serious infection, and although there is a high level of concern around its potential use as a bioterrorism agent, it’s fairly common in nature in certain parts of the world. Anthrax is most commonly acquired from contaminated animal hides, but is also found in the soil in some regions and that may have been the source of contamination of this heroin.

The source of the contaminated heroin hasn’t been discovered, 2 months into the outbreak, so unfortunately, the only way for heroin users to avoid infection is to avoid using heroin – easier said than done.

Hopefully, the awareness campaigns currently being undertaken by the NHS will help ensure rapid treatment for heroin users in the UK – but given that cases have been seen in Germany now, similar campaigns clearly are needed on a much wider scale.

ProMED-mail has a collection of recent articles on the outbreak here, which is worth checking out if your interested in more details.

The QuickStats article also links to a full report on functional difficulties and related health care and educational services usage among American children. I’ll summarize both after the jump.

From the QuickStats, 22% of boys and 14% of girls were reported to have a functional difficulty in at least one of the following areas:

• sensory (problems with seeing or hearing);
• movement (problems with walking, running or playing);
• cognition (problems with memory, or having mental retardation, Down syndrome, autism, or a learning disability);
• emotional or behavioral (attention deficit hyper activity disorder – ADHD, or problems with emotions, concentration, behavior or ability to get along with others).

Less than 5% of both boys and girls had difficulties with sensory or movement. The difference between boys and girls overall was driven by the high prevalence of cognitive and emotional/behavioral problems in boys (about 12% for cognitive and 15% for emotional/behavioral) compared to girls (about 8% for both areas).

For more information, the CDC cites the following report:

SOURCE: Pastor PN, Reuben CA, Loeb M. Functional difficulties among school-aged children: United States, 2001–2007. National health statistics reports; no. 19. Hyattsville, MD: National Center for Health Statistics; 2009. Available at http://www.cdc.gov/nchs/data/nhsr/nhsr019.pdf .

In the full report, it turns out that 80% of children with cognitive difficulties have learning disabilities or problems with memory, 11% have these difficulties plus a condition such as mental retardation, autism or Down syndrome, and 3% have only mental retardation, autism or Down syndrome with no learning difficulty or memory problems.

Among children with emotional/behavioral difficulties, the majority are due to ADHD – 49% of children with emotional/behavioral difficulties have only ADHD and 27% have both ADHD and other serious emotional/behavioral difficulties, while 24% have only serious emotional/behavioral difficulties.

The majority of children who have functional difficulties have difficulties in only one area (67%), while 28% have difficulties in 2 areas and 5% in three or four areas.

Finally, poverty status and health insurance type/status seem to affect access to special education services and health care services among children with functional difficulties, although in opposite ways. 38% of poor children with difficulties in basic actions received special education services, compared to 35% of near poor and 31% of not poor children with such difficulties. On the other hand, 27% of children with basic difficulties who had private health insurance saw a medical specialist, compared to 22% of similar children with public health insurance and only 11% of those who were uninsured.

That said, I’m beginning to find that every time I need to actually use statistics in my research, the statistical tools that I’m equipped with never seem to be right for the task.

For instance, recently boss wanted to know how much statistical power we had to detect a given effect size with this fixed sample size. Easy enough, you say (well, if you’re a statistician or epidemiologist, at least): just look up the formula, plug in your numbers and you’re good to go.

Well… of course, in the “real” world, it’s never that simple.

First, we wanted to compare two groups that were completely different sizes – while textbooks seem to only include formulae for comparing groups of the same size.

Second, instead of values distributed evenly(-ish) around a mean value (i.e. normally distributed), we expect a significant number of observations will have very large values on the outcome of interest. Think of it like trying to compare whether the heights of two groups of high school students are different or not, but having a random number of NBA players in each group – the NBA players are going to have a big effect on the average height if you calculate this using the mean. Researchers interested in our topic typically deal with this by comparing the median values of the outcome, rather than mean values.

Well, it turns out, formulae for power calculations for unbalanced samples are hard to find; formulae for power calculations for median values are even harder to find; and a formula for using median comparisons with unbalanced samples turned out to be impossible to find (within my 4 day deadline!).

So what’s an intrepid young researcher to do? Improvise, of course!

I won’t bore you with the details (any more than I already have). But if you’re interested, or have a solution of your own, I’d love to hear from you in the comments section.

94% of the adverse events reported to VAERS by Jan 8 2010 were not considered serious – symptoms like soreness or redness at injection site.

Out of 110 million doses that were shipped to providers, 33 deaths were reported. There is currently no evidence to suggest that these deaths were caused by the vaccine, but the CDC, the FDA and applicable State governments are currently investigating each of these cases.

There were also 46 reports of Guillan-Barre syndrome, which is less than the average weekly number of diagnoses of Guillan-Barre syndrome among all Americans – whether or not they had received any influenza vaccine.