title: The association between medically unexplained physical symptoms and health care use over two years and the influence of depressive and anxiety disorders and personality traits: a longitudinal study.
abstract: Medically unexplained physical symptoms (MUPS) are highly prevalent and are associated with frequent health care use (HCU). MUPS frequently co-occur with psychiatric disorders. With this study we examined the longitudinal association between MUPS and HCU over 2 years and the influence of depressive and anxiety disorders and personality traits on this association.
  
  
  
  We analysed follow-up data from 2045 to 2981 participants from the Netherlands Study of Depression and Anxiety (NESDA), a multisite cohort study. The study population included participants with a current depressive and/or anxiety disorder, participants with a lifetime risk and/or subthreshold symptoms for depressive and/or anxiety disorders and healthy controls. HCU, measured with the Trimbos and iMTA questionnaire on Costs associated with Psychiatric illness (TIC-P), was operationalized as the number of used medical services and the number of associated contacts. MUPS were measured with the Four Dimensional Symptoms Questionnaire, depressive and anxiety disorders with the Composite International Diagnostic Interview and personality traits with the NEO Five-Factory Inventory. Measurements were taken at baseline, 1 and 2 years follow-up. We used generalized estimating equations (GEE), using HCU at all three measurements as (multivariate) outcome. GEE also takes into account the dependency of observations within participants.
  
  
  
  MUPS were positively associated with HCU over 2 years (medical services: RR 1.020, 95 % CI 1.017-1.022; contacts: RR 1.037, 95 % CI 1.030-1.044). Neuroticism and depression had the strongest influence on the associations. After adjustment for these factors, the associations between MUPS and HCU weakened, but remained significant (services: RR 1.011, 95 % CI 1.008-1.014; contacts: RR 1.023, 95 % CI 1.015-1.032).
  
  
  
  Our results show that MUPS were positively associated with HCU over 2 years, even after adjusting for depressive and anxiety disorders and personality traits.
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. m.denboeft@vumc.nl.
authors.forename: Madelon
authors.initials: M
authors.lastname: den Boeft
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Berend
authors.initials: B
authors.lastname: Terluin
authors.affiliation: Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center, A.J. Ernststraat 1187, 1081 HL, Amsterdam, The Netherlands.
authors.forename: Brenda W J H
authors.initials: BW
authors.lastname: Penninx
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Harm W J
authors.initials: HW
authors.lastname: van Marwijk
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.|Department of Public Health and Primary Care, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
authors.forename: Mattijs E
authors.initials: ME
authors.lastname: Numans
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: van der Wouden
authors.affiliation: Department of General Practice and Elderly Care Medicine, EMGO Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Henriette E
authors.initials: HE
authors.lastname: van der Horst
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000523:psychology*; D002908:Chronic Disease; D003866:Depressive Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D000075384:Neuroticism; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D010554:Personality Disorders / Q000523:psychology; D010555:Personality Inventory; D010808:Physical Examination; D015995:Prevalence; D013001:Somatoform Disorders / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Anxiety disorders; Depressive disorders; Health care use; Medically unexplained physical symptoms; Personality traits; Somatisation