title: Prevalence and Features of a Probable Diagnosis in First-Visit Headache Patients Based on the Criteria of the Third Beta Edition of the International Classification of Headache Disorders: A Prospective, Cross-Sectional Multicenter Study.
abstract: OBJECTIVE
  This study aimed to determine the characteristics and significance of a probable diagnostic entity for primary headache disorder (PHD).
  
  
  BACKGROUND
  A diagnosis of probable primary headache disorder (PPHD) is given when a patient's headache fulfills all but one criteria of the third beta edition of the international classification of headache disorder (ICHD-3β). Despite the uncertainty regarding this diagnosis, the inclusion of a probable diagnosis entity in this manual may aid in the accurate classification of headache disorders and allow effective treatment strategies to be started at the patient's initial visit.
  
  
  METHODS
  This cross-sectional multicenter registry study assessed first-visit patients with complaints of headaches who presented at the outpatient clinics of 11 neurologists in Korea. The classification of a headache disorder was made according to the criteria of the ICHD-3β by each investigator based on the initial evaluation of the patient or by a consensus meeting for uncertain cases. The rates of a probable diagnosis among PPHD patients were assessed and the clinical characteristics of these patients were compared with those of patients with a diagnosis of definite primary headache disorder (DPHD).
  
  
  RESULTS
  A total of 1429 patients were diagnosed with PHD, and 305 (21.3%) of these patients had PPHD. The proportions of PPHD differed among the subtypes of DPHD as follows: migraines (16.1%), tension-type headaches (TTH; 33%), trigeminal autonomic cephalalgia (TAC; 40.9%), and other PHD (14%, P < .001). Patients with PPHD had less severe headache intensity than patients with DPHD (5.8 ± 2.2 vs. 6.5 ± 2.1, respectively, P < .001) as well as a shorter duration of headache from onset (median: 1 vs. 4 months, respectively, P < .001). The most common criteria missing for a definite diagnosis in the PPHD patients were total frequency (52.1%), duration of attack (14.4%), and accompanying symptoms (13.1%).
  
  
  CONCLUSIONS
  A probable diagnosis was given to 21.3% of the first-visit PHD patients due to incomplete or atypical presentations of the headaches. The incorporation of a probable diagnosis into the ICHD-3β may be useful for reducing the diagnoses of unspecified headaches.
authors.affiliation: Department of Neurology, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Soo-Kyoung
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Neurology, Kangbuk Samsung Medical Center Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Heui-Soo
authors.initials: HS
authors.lastname: Moon
authors.affiliation: Department of Neurology, National Police Hospital, Seoul, Korea.
authors.forename: Myong-Jin
authors.initials: MJ
authors.lastname: Cha
authors.affiliation: Department of Neurology, Bundan Jesaeng Hospital, Seongnam, Korea.
authors.forename: Byung-Su
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Neurology, Eulji University School of Medicine, Seoul, Korea.
authors.forename: Byung-Kun
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Neurology, Uijeongbu St.Mary's Hospital the Catholic University of Korea, Uijeongbu, Korea.
authors.forename: Jeong-Wook
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Neurology, Chung-Ang University Hospital Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Kwang-Yeol
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Neurology, Chuncheon Sacred Heart Hospital Hallym University College of Medicine, Chuncheon, Korea.
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital Hallym University College of Medicine, Anyang, Korea.
authors.forename: Min-Kyung
authors.initials: MK
authors.lastname: Chu
authors.affiliation: Department of Neurology, Ewha Womans University, Seoul, Korea.
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Song
authors.affiliation: Department of Neurology, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Jae-Moon
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Neurology, Dongtan Sacred Heart Hopital, Hallym University College of Medicine, Hwaseong, Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D020773:Headache Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012720:Severity of Illness Index; D055815:Young Adult
keywords: definite; diagnosis; international classification of headache disorders; outpatient headache clinic; primary headache disorder; probable; tension-type headache