title: Self-reported visual impairment, physical activity and all-cause mortality: The HUNT Study.
abstract: OBJECTIVE
  To examine the associations of self-reported visual impairment and physical activity (PA) with all-cause mortality.
  
  
  METHODS
  This prospective cohort study included 65,236 Norwegians aged ⩾20 years who had participated in the Nord-Trøndelag Health Study (HUNT2, 1995-1997). Of these participants, 11,074 (17.0%) had self-reported visual impairment (SRVI). The participants' data were linked to Norway's Cause of Death Registry and followed throughout 2012. Hazard ratios and 95% confidence intervals (CI) were assessed using Cox regression analyses with age as the time-scale. The Cox models were fitted for restricted age groups (<60, 60-84, ⩾85 years).
  
  
  RESULTS
  After a mean follow-up of 14.5 years, 13,549 deaths were identified. Compared with adults with self-reported no visual impairment, the multivariable hazard ratios among adults with SRVI were 2.47 (95% CI 1.94-3.13) in those aged <60 years, 1.22 (95% CI 1.13-1.33) in those aged 60-84 years and 1.05 (95% CI 0.96-1.15) in those aged ⩾85 years. The strength of the associations remained similar or stronger after additionally controlling for PA. When examining the joint associations, the all-cause mortality risk of SRVI was higher for those who reported no PA than for those who reported weekly hours of PA. We found a large, positive departure from additivity in adults aged <60 years, whereas the departure from additivity was small for the other age groups.
  
  
  CONCLUSIONS
  Adults with SRVI reporting no PA were associated with an increased all-cause mortality risk. The associations attenuated with age.
authors.affiliation: 1 Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Norway.
authors.forename: Audun
authors.initials: A
authors.lastname: Brunes
authors.affiliation: 2 Department of Epidemiology, Rollins School of Public Health, Emory University, USA.|3 Department of Biostatistics, Rollins School of Public Health, Emory University, USA.
authors.forename: W Dana
authors.initials: WD
authors.lastname: Flanders
authors.affiliation: 1 Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Norway.|4 Department of Visual Impairment, Statped Mid-Norway, Norway.
authors.forename: Liv Berit
authors.initials: LB
authors.lastname: Augestad
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D057566:Self Report; D014786:Vision Disorders / Q000453:epidemiology*
keywords: All-cause mortality; HUNT study; physical activity; prospective cohort study; self-reported; visual impairment