title: An up-date on health-related quality of life in myasthenia gravis -results from population based cohorts.
abstract: Current available therapies control Myasthenia gravis (MG) reasonably well, but Health Related Quality of life (HRQOL) remains lower than expected. The aim was provide insights in how HRQOL in MG stands across borders and time, compare the scores to general population controls and other chronic disorders and assess the impact of potential predictors for quality of life such as a) clinical characteristics b) antibodies c) thymoma and d) treatment in a population-based cohort.
  
  
  METHODS
  We designed a population-based cross-sectional study including 858 patients, 373 from Norway and 485 from the Netherlands. The Short Form Health Survey 36 (SF-36) and a cross-cultural validated questionnaire were used. Data were in addition compared to the general population, other chronic diseases and previous studies.
  
  
  RESULTS
  Mean physical composite score was 59.4 and mental composite score 69.0 with no differences between the countries. The mean HRQOL score was lower in patients with bulbar and generalized symptoms (p < 0.001) compared to sex and age adjusted healthy controls, but not in patients with ocular symptoms or patients in remission. Multivariate analysis revealed that female gender, generalized symptoms and use of secondary immunosuppressive drugs at the time of testing were risk factors for reduced HRQOL.
  
  
  CONCLUSIONS
  Remission and absence of generalized symptoms were favorable factors for HRQOL in MG patients. Historically, the HRQOL levels have not changed since 2001 and no new clinical predictors could be detected in this exhaustive population-based study. Further studies should explore the impact of non clinical factors like ethnic variations, socio-economic and hormonal factors on HRQOL.
authors.affiliation: Department of Neurology, Oslo University Hospital, Ullevål and Rikshospitalet, Ullevål, Pb. 4950 Nydalen, 0424, Oslo, Norway. marbol@ous-hf.no.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway. marbol@ous-hf.no.
authors.forename: M I
authors.initials: MI
authors.lastname: Boldingh
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. dekkerluuk@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Dekker
authors.affiliation: Department of Neurology, Oslo University Hospital, Ullevål and Rikshospitalet, Ullevål, Pb. 4950 Nydalen, 0424, Oslo, Norway. angman@ous-hf.no.
authors.forename: A H
authors.initials: AH
authors.lastname: Maniaol
authors.affiliation: Department of Neurology, Oslo University Hospital, Ullevål and Rikshospitalet, Ullevål, Pb. 4950 Nydalen, 0424, Oslo, Norway. cathrine.brunborg@ous-hf.no.|Department of Epidemiology and Biostatistics, Oslo University Hospital, Ullevål, Oslo, Norway. cathrine.brunborg@ous-hf.no.
authors.forename: C
authors.initials: C
authors.lastname: Brunborg
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. a.f.lipka@lumc.nl.
authors.forename: A F
authors.initials: AF
authors.lastname: Lipka
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. e.h.niks@lumc.nl.
authors.forename: E H
authors.initials: EH
authors.lastname: Niks
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. j.j.g.m.verschuuren@lumc.nl.
authors.forename: J J G M
authors.initials: JJ
authors.lastname: Verschuuren
authors.affiliation: Department of Neurology, Oslo University Hospital, Ullevål and Rikshospitalet, Ullevål, Pb. 4950 Nydalen, 0424, Oslo, Norway. Chantal.tallaksen@medisin.uio.no.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Chantal.tallaksen@medisin.uio.no.
authors.forename: C M E
authors.initials: CM
authors.lastname: Tallaksen
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000453:epidemiology / Q000523:psychology* / Q000628:therapy; D009426:Netherlands / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D012307:Risk Factors; D011795:Surveys and Questionnaires / Q000592:standards*