title: Accumulation of psychosocial and lifestyle factors and risk of low back pain in adolescence: a cohort study.
abstract: OBJECTIVE
  Low back pain (LBP) is common already in adolescence, and many risk indicators including both psychosocial and lifestyle factors have been recognized. Our purpose was to assess whether the co-occurrence of psychosocial (externalizing and internalizing) problems and lifestyle factors (leisure time physical activity, sedentary behaviour, sleep, smoking, and overweight/obesity) associate with LBP at 16 years cross-sectionally or with new LBP at 18-year follow-up.
  
  
  METHODS
  The study population, drawn from the Northern Finland Birth Cohort 1986, consisted of 1625 participants (712 boys and 913 girls) who completed a questionnaire on potential explanatory factors at 16 years and on LBP at 16 and 18 years. The outcome measure was 'reporting LBP' or 'consultation for LBP' during the past 6 months. Latent Class Analysis (LCA) was utilized to study the co-occurrence of the explanatory factors.
  
  
  RESULTS
  Among both genders, four clusters were found. Externalizing behaviour problems were associated with 'reporting LBP' (RR 1.5, boys 1.4, girls) and 'consultation for LBP' (RR 1.6 for both genders) at baseline among both genders. In addition, the cluster of multiple risk behaviours was associated with both 'reporting LBP' (RR 1.3) and 'consultation for LBP' (RR 2.5) and the obese cluster with 'consultation for LBP' (RR 1.7) among girls. Externalizing behaviour problems at 16 years predicted 'consultation for LBP' at 18 years among girls (RR 3.6).
  
  
  CONCLUSIONS
  Our results stress the role of psychosocial factors in reporting and seeking care for adolescent LBP.
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland. paula.h.mikkonen@ppshp.fi.
authors.forename: Paula
authors.initials: P
authors.lastname: Mikkonen
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Eveliina
authors.initials: E
authors.lastname: Heikkala
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Paananen
authors.affiliation: Finnish Institute of Occupational Health, Statistics and Health Economics, Oulu, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Remes
authors.affiliation: Department of Public Health, University of Helsinki, Helsinki, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Taimela
authors.affiliation: Institute of Health Sciences, University of Oulu, Oulu, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Auvinen
authors.affiliation: Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.|Finnish Institute of Occupational Health, Health and Work Ability, and Disability Prevention Centre, Oulu, Finland.
authors.forename: Jaro
authors.initials: J
authors.lastname: Karppinen
mesh_terms: D000293:Adolescent; D016000:Cluster Analysis; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007389:Internal-External Control; D008019:Life Style; D017116:Low Back Pain / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: Adolescent; Care seeking; Cohort studies; Latent class analysis; Low back pain; Risk factors