title: Is this back pain killing me? All-cause and cardiovascular-specific mortality in older Danish twins with spinal pain.
abstract: BACKGROUND
  Few studies have examined the potentially reduced life expectancy associated with spinal pain (i.e. low back and neck pain) in an ageing population, particularly after controlling for familial factors, including genetics.
  
  
  METHODS
  We investigated whether spinal pain increased the rate of all-cause and disease-specific cardiovascular mortality in older Danish twins aged ≥70 years. Data from 4391 participants collected at baseline were linked with the Danish Cause of Death Registry with the study ending on 31 December 2014. Two crude and adjusted Cox proportional hazards regression analyses determined the rate of all-cause and disease-specific cardiovascular mortality by baseline spinal pain exposure; unpaired (total sample analysis) and twin pair (intra-pair analysis). Analyses were also adjusted for confounders; baseline physical functional ability and depressive symptoms. Competing risk regression models determined the rate of cardiovascular mortality, adjusting for similar confounders and using the total sample only.
  
  
  RESULTS
  Spinal pain was associated with an increased rate of all-cause mortality, hazard ratio (HR): 1.13 [95% confidence interval (CI): 1.06-1.21]. There was no association between spinal pain and cardiovascular disease mortality, sub-distribution hazard ratio (SHR): 1.08 [95% CI 0.96-1.21]. After adjusting for confounders (physical functional ability and depressive symptoms), the association became non-significant. All intra-pair analyses were statistically non-significant, although greater in magnitude for monozygotic twins.
  
  
  CONCLUSIONS
  Older people reporting spinal pain have 13% increased risk of mortality per years lived but the connection is not causal. We found no association between spinal pain and cardiovascular-specific mortality. The influence of shared familial factors is unlikely.
  
  
  CONCLUSIONS
  Older people reporting spinal pain have 13% increased risk of mortality per year lived. However, this association is not likely to be causal, with the relevant confounders contributing to this relationship. Thus, pain in the spine may be part of a pattern of poor health, which increases mortality risk in the older population.
authors.affiliation: Faculty of Health Sciences, The University of Sydney, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Fernandez
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense M, Denmark.|Dalla Lana School of Public Health, University of Toronto, ON, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Boyle
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense M, Denmark.|Nordic Institute of Chiropractic and Clinical Biomechanics, University of Southern Denmark, Odense M, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hartvigsen
authors.affiliation: The George Institute for Global Health, Sydney Medical School, The University of Sydney, NSW, Australia.|Institute of Bone and Joint Research, The Kolling Institute, Sydney Medical School, The University of Sydney, NSW, Australia.
authors.forename: M L
authors.initials: ML
authors.lastname: Ferreira
authors.affiliation: Faculty of Health Sciences, The University of Sydney, NSW, Australia.
authors.forename: K M
authors.initials: KM
authors.lastname: Refshauge
authors.affiliation: The George Institute for Global Health, Sydney Medical School, The University of Sydney, NSW, Australia.
authors.forename: C G
authors.initials: CG
authors.lastname: Maher
authors.affiliation: Danish Aging Research Center, Institute of Public Health, Epidemiology, University of Southern Denmark, Odense C, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Christensen
authors.affiliation: Australian Twin Registry, Centre for Molecular, Environmental, Genetic, and Analytic Epidemiology, The University of Melbourne, Vic., Australia.
authors.forename: J L
authors.initials: JL
authors.lastname: Hopper
authors.affiliation: Faculty of Health Sciences, The University of Sydney, NSW, Australia.
authors.forename: P H
authors.initials: PH
authors.lastname: Ferreira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001416:Back Pain / Q000401:mortality*; D002318:Cardiovascular Diseases / Q000401:mortality*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D019547:Neck Pain / Q000401:mortality*; D012042:Registries; D012306:Risk; D014430:Twins, Monozygotic