title: Is neck pain associated with worse health-related quality of life 6 months later? A population-based cohort study.
abstract: BACKGROUND
  Current evidence suggests that neck pain is negatively associated with health-related quality of life (HRQoL). However, these studies are cross-sectional and do not inform the association between neck pain and future HRQoL.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the association between increasing grades of neck pain severity and HRQoL 6 months later. In addition, this longitudinal study examines the crude association between the course of neck pain and HRQoL.
  
  
  METHODS
  This is a population-based cohort study.
  
  
  METHODS
  Eleven hundred randomly sampled Saskatchewan adults were included.
  
  
  METHODS
  Outcome measures were the mental component summary (MCS) and physical component summary (PCS) of the Short-Form-36 (SF-36) questionnaire.
  
  
  METHODS
  We formed a cohort of 1,100 randomly sampled Saskatchewan adults in September 1995. We used the Chronic Pain Questionnaire to measure neck pain and its related disability. The SF-36 questionnaire was used to measure physical and mental HRQoL 6 months later. Multivariable linear regression was used to measure the association between graded neck pain and HRQoL while controlling for confounding. Analysis of variance and t tests were used to measure the crude association among four possible courses of neck pain and HRQoL at 6 months. The neck pain trajectories over 6 months were no or mild neck pain, improving neck pain, worsening neck pain, and persistent neck pain. Finally, analysis of variance was used to examine changes in baseline to 6-month PCS and MCS scores among the four neck pain trajectory groups.
  
  
  RESULTS
  The 6-month follow-up rate was 74.9%. We found an exposure-response relationship between neck pain and physical HRQoL after adjusting for age, education, arthritis, low back pain, and depressive symptomatology. Compared with participants without neck pain at baseline, those with mild (β=-1.53, 95% confidence interval [CI]=-2.83, -0.24), intense (β=-3.60, 95% CI=-5.76, -1.44), or disabling (β=-8.55, 95% CI=-11.68, -5.42) neck pain had worse physical HRQoL 6 months later. We did not find an association between neck pain and mental HRQoL. A worsening course of neck pain and persistent neck pain were associated with worse physical HRQoL.
  
  
  CONCLUSIONS
  We found that neck pain was negatively associated with physical but not mental HRQoL. Our analysis suggests that neck pain may be a contributor of future poor physical HRQoL in the population. Raising awareness of the possible future impact of neck pain on physical HRQoL is important for health-care providers and policy makers with respect to the management of neck pain in populations.
authors.affiliation: Department of Graduate Education and Research, Canadian Memorial Chiropractic College, 6100 Leslie Street, North York, Ontario, Canada. M2H 3J1. Electronic address: pnolet@rogers.com.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Nolet
authors.affiliation: Department of Graduate Education and Research, Canadian Memorial Chiropractic College, 6100 Leslie Street, North York, Ontario, Canada. M2H 3J1; Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, 6th floor, 155 College Street, Toronto, Ontario, Canada. M5T 3M7; Toronto Western Research Institute, University Health Network, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, Canada. M5T 2S8.
authors.forename: Pierre
authors.initials: P
authors.lastname: Côté
authors.affiliation: Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, 6th floor, 155 College Street, Toronto, Ontario, Canada. M5T 3M7; Department of Health Sciences, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, Canada. P7B 5E1; Institute for Work & Health, 481 University Avenue, Toronto, Ontario, Canada. M5G 2E9.
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Kristman
authors.affiliation: Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, 6th floor, 155 College Street, Toronto, Ontario, Canada. M5T 3M7; Toronto Western Research Institute, University Health Network, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, Canada. M5T 2S8.
authors.forename: Mana
authors.initials: M
authors.lastname: Rezai
authors.affiliation: Department of Public Health Sciences, The Alberta Centre for Injury Control and Research, School of Public Health, University of Alberta, 8308 114 Street Northwest, Edmonton, AB T6G 2E1.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Carroll
authors.affiliation: Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, 6th floor, 155 College Street, Toronto, Ontario, Canada. M5T 3M7; Toronto Western Research Institute, University Health Network, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, Canada. M5T 2S8; Institute for Sport Science and Clinical Biomechanics, Faculty of Health, University of Southern Denmark, Campusvej 55 5230, Odense M, Denmark.
authors.forename: J David
authors.initials: JD
authors.lastname: Cassidy
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000453:epidemiology* / Q000523:psychology; D011788:Quality of Life; D011795:Surveys and Questionnaires
keywords: Cohort study; Disability; Epidemiology; Health-related quality of life; Neck pain; Risk