title: Determining of migraine prognosis using latent growth mixture models.
abstract: BACKGROUND
  This paper presents a retrospective study to classify patients into subtypes of the treatment according to baseline and longitudinally observed values considering heterogenity in migraine prognosis. In the classical prospective clinical studies, participants are classified with respect to baseline status and followed within a certain time period. However, latent growth mixture model is the most suitable method, which considers the population heterogenity and is not affected drop-outs if they are missing at random. Hence, we planned this comprehensive study to identify prognostic factors in migraine.
  
  
  METHODS
  The study data have been based on a 10-year computer-based follow-up data of Mersin University Headache Outpatient Department. The developmental trajectories within subgroups were described for the severity, frequency, and duration of headache separately and the probabilities of each subgroup were estimated by using latent growth mixture models. SAS PROC TRAJ procedures, semiparametric and group-based mixture modeling approach, were applied to define the developmental trajectories.
  
  
  RESULTS
  While the three-group model for the severity (mild, moderate, severe) and frequency (low, medium, high) of headache appeared to be appropriate, the four-group model for the duration (low, medium, high, extremely high) was more suitable. The severity of headache increased in the patients with nausea, vomiting, photophobia and phonophobia. The frequency of headache was especially related with increasing age and unilateral pain. Nausea and photophobia were also related with headache duration.
  
  
  CONCLUSIONS
  Nausea, vomiting and photophobia were the most significant factors to identify developmental trajectories. The remission time was not the same for the severity, frequency, and duration of headache.
authors.affiliation: Department of Biostatistics, Mersin University Faculty of Medicine, Mersin, Turkey. bahartasdelen@gmail.com
authors.forename: Bahar
authors.initials: B
authors.lastname: Tasdelen
authors.forename: Aynur
authors.initials: A
authors.lastname: Ozge
authors.forename: Hakan
authors.initials: H
authors.lastname: Kaleagasi
authors.forename: Semra
authors.initials: S
authors.lastname: Erdogan
authors.forename: Tufan
authors.initials: T
authors.lastname: Mengi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D012001:Hyperacusis / Q000503:physiopathology; D008875:Middle Aged; D008881:Migraine Disorders / Q000473:pathology* / Q000503:physiopathology; D009325:Nausea / Q000503:physiopathology; D020795:Photophobia / Q000503:physiopathology; D012189:Retrospective Studies; D014839:Vomiting / Q000503:physiopathology; D055815:Young Adult