To further investigate whether fMRI can also be used to differentiate between prospective responders and nonresponders to anti-TNF, we undertook a follow-up investigation [ 67].
Health care center personnel contacted prospective responders by phone and invited them to fill out the questionnaire at the primary health care center.
The first author then developed a sex- and age-matched list of prospective Assyrian/Syrian and Swedish responders.
Long-term results were assessed in a prospective cohort-study of steroid responders.
Long-term effectiveness was evaluated in an open prospective cohort-study of steroid responders during a follow-up period of 12 months.
Second, it is unknown whether characteristics of hard-to-recruit responders in a prospective population based cohort study are similar across age group and survey method.
A major strength of our study is the prospective design and the high proportion of responders at follow-up (97%, 111/114) which prevented selection bias.
As some patients showed marked reduction in migraine days than headache days we devised our own responder criteria (Hull Criteria) for analysing prospective patients in this study.
The retrospective character of the analysis and the small number of non-responders are further limitations, which warrant prospective follow-up studies in order to validate our results.
With regard to rechallenge, we are performing a prospective phase II trial of gefitinib rechallenge to gefitinib-responders following chemotherapy.
