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QIMR Neurogenetics Laboratory Homepage > Dale’s Homepage > Dale's
Migraine Research
My
Migraine Research
- All
of my papers can be downloaded as PDFs here.
- The
migraine questionnaires used in the two original studies:
- Between
1993-1995, a telephone interview in which a diagnostic assessment of
psychiatric disorders, including alcohol use and abuse, anxiety,
depression and phobias, was administered to an older
cohort of twins, born 1902-1964. A total of 5996 individual
twins completed the 1993 interview (Heath et al 1997).
- Between
1996-2000, a younger
cohort of twins (born 1961-1975) undertook a more
detailed semi-structured telephone interview, designed to assess
physical, psychological and social manifestations of alcoholism and
related disorders (Heath et al 2001); 6265 individual twins completed
the interview.
- Although
the wording of questions was identical between cohorts, the younger
cohort were asked questions relating to 10 International Headache
Society (IHS) diagnostic symptom criteria [see Table 1 and Figure 1 of
Nyholt
et al. (2004)], while the older cohort were not asked questions
relating to “at least five migraine/episodes of headache during
lifetime” (“>5 episodes”, “A”), “average typical migraine/headache
lasts between 4 and 72 hours” (“4-72hr”, “B”) and “pain associated
with headache described as moderate or severe” (“moderate/severe”, “C3a”).
- In
my latent class analysis (LCA) approach to obtain empirical clusters
of migraine symptoms (Nyholt
et al. 2004), the younger and older cohort data are combined, thus
allowing the LCA to impute class membership in the older cohort, based
on the pattern of all 10 symptoms observed in the younger cohort. To
examine the accuracy of imputed class memberships we compared the
classification results for the younger dataset utilizing all 10
available IHS symptoms, to the classification results for the younger
dataset utilizing only the 7 IHS symptoms which were available for the
older cohort. Compared to using all 10 symptoms, when only the 7
symptoms were used, these analyses found 98.5% and 96.0% of
individuals were correctly classified as unaffected and affected
respectively, indicating that the three missing symptoms in the older
cohort would have negligible effect on the accuracy of individual LCA
migraine diagnoses (Nyholt
et al. 2005).
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