title: Analysis of risk factors for medication-overuse headache relapse: a clinic-based study in China.
abstract: BACKGROUND
  Medication overuse headache (MOH) is the third most prevalent headache type after migraine and tension-type headache. A large number of studies on the long-term prognosis have shown that MOH has a high relapse rate after treatment. Although MOH relapse-related risk factors have been reported, no related research has been performed in China. Therefore, the purpose of this study was to analyze and evaluate the risk factors for MOH relapse in China.
  
  
  METHODS
  Eighty-six out-patients of Shandong Provincial Hospital who were initially diagnosed with MOH, and who had successful withdrawal treatment within 2 months, were chosen from March 2012 to July 2013. All subjects were followed up by the investigators of this study. Of the 86 subjects, 27 who had relapsed were compared with 59 who had not relapsed (i.e. the controls). Based on a standardized questionnaire, a database was created (with Microsoft Excel 2010). The data, which included 38 indexes, were analyzed by univariate analysis with chi-square test, Fisher's exact test, t-test, or paired rank test. The statistically correlated (P<0.05) variables were chosen as the independent variables, thereby enabling the calculation of the non-conditional multivariate stepwise logistic regression.
  
  
  RESULTS
  The independent risk factors for medication-overuse headache relapse were determined as headache frequency before drug withdrawal, duration of primary headache, and headache frequency after drug withdrawal.
  
  
  CONCLUSIONS
  Headache frequency before drug withdrawal, duration of primary headache, and headache frequency after drug withdrawal may be the independent risk factors for MOH relapse in China.
authors.affiliation: Department of Neurology, Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, 250021, China. yanzhihui7602@163.com.|Department of Neurology, Yantaishan Hospital, Yantai, Shandong, 264001, China. yanzhihui7602@163.com.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Yan
authors.affiliation: Department of Neurology, Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, 250021, China. chenyuan815012903@qq.com.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Neurology, Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, 250021, China. chencf301@163.com.
authors.forename: Chunfu
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Neurology, Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, 250021, China. lccbright88@163.com.
authors.forename: Congcong
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Neurology, Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, 250021, China. 15969683747@163.com.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Diao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000700:Analgesics / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001569:Benzodiazepines / Q000627:therapeutic use; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D051271:Headache Disorders, Secondary / Q000145:classification / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors; D018781:Tension-Type Headache / Q000188:drug therapy; D013997:Time Factors; D055815:Young Adult
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004365:Drugs, Chinese Herbal; D001569:Benzodiazepines