Uncommon levels, or surprise values, of potential headache triggers were associated with headache activity, according to a study published in Headache.
Researchers completed a secondary analysis of the Headache Prediction Study to evaluate the effect surprise values, or the amount a trigger differs from the normal routine, has on causing a headache attack. Trigger surprise values were defined as daily variations in caffeine intake, alcohol consumption, stress levels, and mood disturbances.
Diary entries from study participants with diagnosed episodic migraine were assessed to measure headache activities, daily stress, mood states, and alcohol and caffeine intake. The variable of surprise value was calculated using the probability that a particular headache trigger would deviate from an expected normal level, either greater or less than, on a given day. The primary outcome was the presence or absence of a headache today based on the surprise value from yesterday’s triggers.
Of the 95 study participants, 90.5% were women, 87.4% were white, the mean age was 40 years old, and headache attacks were experienced on 38.5% day during the study. All of the study triggers had a linear relationship with current headache, surprise value, and headache plus surprise value (P <.001, for all). For example, “drinking 1 cup of coffee each day would not pose a risk for headache, but drinking 4 cups in a single day when only 1 cup is typically encountered (ie, expected) would be predictive of increased headache risk.”
The odds ratio for each trigger surprise value and the risk for a future headache fell in a range between 1.11 for alcohol intake (P =.05) to 1.30 for stress levels (P <.0001). When the individual trigger surprise values were added together, the sum surprise score had an odds ratio of 1.35 for the risk for future headaches (P <.0001).
Limitations of this study include using results from a secondary, retrospective analysis, using the same data to describe the model and calculated estimates, and the lack of temporal consideration in regards to surprise triggers and headaches.
The researchers concluded that “[r]are values of headache triggers, or surprising values, were found to have consistent associations with headache activity across a variety of triggers (caffeine, alcohol, stress, and mood).”
Turner DP, Lebowitz AD, Chtay I, Houle TT. Headache triggers as surprise [published online March 28, 2019]. Headache. doi: 10.1111/head.13507