title: Fear avoidance beliefs influence duration of sick leave in Spanish low back pain patients.
abstract: METHODS
  Follow-up study.
  
  
  OBJECTIVE
  To estimate the influence of fear avoidance beliefs (FAB) on 1-year low back pain (LBP)-related sick leave.
  
  
  BACKGROUND
  As opposed to Anglo-Saxon and Northern European subjects, in Spanish LBP patients the influence of FAB on disability and quality of life is virtually irrelevant.
  
  
  METHODS
  Twelve primary care and 9 hospital services from 7 different regions of Spain recruited 165 workers who visited the National Health Service for LBP. None was excluded. On their first visit and 14 days later, patients were given 2 independent Visual Analogue Scales (VAS) for LBP and leg pain, as well as the validated Spanish versions of the Fear Avoidance Beliefs (FABQ), Roland-Morris (RMQ), and SF-12 questionnaires. During the following 12-month period, the number of days on sick leave because of LBP was registered.
  
  
  RESULTS
  Differences in sick leave throughout the study period were associated with baseline differences in chronicity, severity of low back (not referred) pain, disability, FAB, physical and mental quality of life, being on sick leave when entering the study, and duration of previous sick leave. Ordinal logistic regression models showed that each additional point in the total FAB baseline score increases by 2.4% the odds of being on sick leave for up to 60 days during the following year and by 7.7% the odds of being sick listed for 61 days or more. Corresponding figures for FAB-Work scores are 4.2% and 11%. No variable modifies the effect of FAB on sick leave.
  
  
  CONCLUSIONS
  Although in Spanish patients the influence of FAB on disability and quality of life is irrelevant, baseline FABQ score does influence LBP-related sick leave during the following year. This seems to be a direct effect of FAB, since there is no confounding by any other variable.
authors.affiliation: Departamento Científico, Fundación Kovacs, Palma de Mallorca, Spain. kovacs@kovacs.org
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Kovacs
authors.forename: Alfonso
authors.initials: A
authors.lastname: Muriel
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Castillo Sánchez
authors.forename: José María
authors.initials: JM
authors.lastname: Medina
authors.forename: Ana
authors.initials: A
authors.lastname: Royuela
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000328:Adult; D001008:Anxiety Disorders / Q000209:etiology / Q000523:psychology*; D001362:Avoidance Learning / Q000502:physiology*; D002908:Chronic Disease / Q000523:psychology; D003466:Cultural Characteristics; D003469:Culture; D004185:Disability Evaluation; D005239:Fear / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000150:complications / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012044:Regression Analysis; D012655:Self-Evaluation Programs; D018582:Sick Leave / Q000706:statistics & numerical data* / Q000639:trends; D013030:Spain; D011795:Surveys and Questionnaires