If there is a relationship between snoring and headache, this may have introduced a misclassification bias resulting in a slight overestimation of headache in participants without obstructive sleep apnea in our study [29, 35].
Since there may be a relationship between snoring and headache, this may have introduced a misclassification bias which contributed to a slight overestimation of headache in participants without obstructive sleep apnea in the current study [28, 29].
There is a possibility of non-differential misclassification of diagnosis that might weaken real associations, but we think this is a minor problem as the prevalence of headache and MSC in the current population is consistent with data from other population-based studies in the Western countries [ 10, 12, 38].
Among primary headaches, the International Classification of Headache Disorders distinguishes between tension headache (the most common), migraine, and cluster headache.
Data extraction Frequency of headaches (number of headache attacks for migraine and number of days with headache for tension-type headaches), intensity of headache, and headache index.
Older children complained of headache.
55 Measures of headache included frequency of headache (19 studies), headache intensity (n=5), and headache index (n=13).
The International Classification of Headache Disorders (2004).
The burden of headache is enormous.
Tension headaches are the most common type of headache.
