For the past five years at least, I have been suffering from migraines. Though I don’t suffer from “classic” migraines–I don’t have the painful headaches that force one to lie down in a darkened room, for instance–my migraines are debilitating enough, as they make me sensitive to light (and sometimes to noise), they can last up to seven days, and in the worst of cases, I have severe nausea and have to spend a few days in bed while I recover.<\/p>\n
My migraines have gotten a lot better since coming to Minnesota, thank God, but one of the things I\u00a0have been abstaining from these past few years has been drinking wine, because wine is often thought to cause migraines.\u00a0The upside is that I have discovered the wonderful world of whiskeys as a result of not drinking wine; the downside is… Well, having to abstain from\u00a0wine is a serious downside.<\/p>\n
After a few years of not drinking wine and still suffering from migraines, I decided at the beginning of this year to determine once and for all whether my migraines were actually caused by drinking wine. So I did something simple enough: I ran an RCT on myself. I took a spreadsheet and, for a period of 50 days, I decided to randomize each day into treatment (i.e., a day where I would drink wine) and control (i.e., a day where I would abstain from wine).<\/p>\n
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(And before the critical thinkers\u00a0among you chime in with the same comment: Yes, I know that this does not allow doing a double blind study, thanks.)<\/p>\n
Further, within each treatment day, I randomized how much wine I should drink (i.e., 0.25 or 0.5 cups). In my spreadsheet, other than the date and the number of the observation (t), I thus created two columns: wine_treat<\/em> (a dummy for whether a given day was randomly assigned as a “wine” day), and q_treat\u00a0<\/em>(a dummy for how much wine I was to drink on a given wine day). These variables can be used to estimate the intent to treat (ITT).<\/p>\n I know myself too well, however, and I knew that I might have a hard time sticking to random assignment. So I made sure to create two more variables, whose names are self-explanatory:\u00a0wine_actual\u00a0<\/em>\u00a0and\u00a0q_actual<\/em>, which measure whether I actually stuck to a day’s random assignment and how much wine I really had that day. These variables can be used to estimate the local average treatment effect, instrumenting _actual<\/em> variables with _treat<\/em> variables.<\/p>\n Finally, I decided to add in some controls:\u00a0red<\/em>, a dummy variable\u00a0for whether I had had red wine (red wine being thought as “more likely” to give migraines by the medical profession than white wine), other_alc<\/em> for whether I had other kinds of alcohol that day (i.e., whiskey, beer), and\u00a0stress<\/em>\u00a0for whether this had been a particularly stressful day. And of course, for each date, I have a variable called\u00a0migraine<\/em>, which measures whether I have experienced migraine onset the next day (when I have a migraine, I almost always wake up with it and to my knowledge, I have never had a migraine start later during the day, after the normal time where I would have wine, i.e., dinner time).<\/p>\n