Table 5 Speech pattern differences in patients with PTH during days of headache (headache ‘yes’) compared to days of headache freedom (headache ‘no’). Results of linear mixed model with individuals as random effects controlled for age and sex. Random-intercepts model = Bolded p-values indicate that the mean of the speech measure is different when the participant has a headache as compared when she/he is headache free (within-person effect). Random-intercepts-random-slopes model = Bolded p-values indicate that there were differences not only on the mean of the speech measures between the headache states but also on how participant differed on their changes on speech measures between the two headache states (within- and between- person effects).

From: Altered speech patterns in subjects with post-traumatic headache due to mild traumatic brain injury