title: The impact of age and comorbidity on the progression of disability in late-onset sequelae of poliomyelitis.
abstract: OBJECTIVE
  To describe the functional course over 5 years in patients aged 45 to 85 years with late-onset sequelae of poliomyelitis (LOSP) and to explore the impact of age and comorbidity.
  
  
  METHODS
  Prospective cohort study with 5 measurements over 5 years.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Subjects with LOSP (N=168).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  FIM, Medical Outcomes Study 36-Item Short Form health survey for physical functioning subscale (SF-36-PF), walking test, isokinetic quadriceps strength, and cumulative illness rating scale (CIRS) for comorbidity.
  
  
  RESULTS
  The FIM score (mean baseline +/- SD, 121+/-4) and SF-36-PF (mean baseline +/- SD, 39.5+/-24) decreased 2.2 and 3.7 points, respectively, over 5 years independent of age. The distance walked in 2 minutes (mean baseline +/- SD, 126.2+/-34m) decreased 4.5m, quadriceps strength (mean baseline +/- SD, 88.0+/-42.2Nm) declined 7Nm (8%), and CIRS (median baseline=6; range, 0-21) increased 1.5 points. A higher CIRS score was correlated with a lower FIM score and faster decrease in the FIM. A longitudinal model of factors associated with the FIM included sex, age, leg strength sum-score, arm strength sum-score, and CIRS score. The interaction of CIRS and leg strength sum-score with follow-up time was significant. A model of factors associated with SF-36-PF included sex, age, leg strength sum-score, and CIRS score.
  
  
  CONCLUSIONS
  Despite a reduction in muscle strength, disability increased little in patients with LOSP. Increased age and comorbidity has a negative effect on disability. Comorbidity and the severity of leg paresis affected the course of functional independence but not the course of perceived physical functioning.
authors.affiliation: Department of Rehabilitation Medicine, Vrije Universiteit University Medical Center, 1007 MB Amsterdam, The Netherlands. j.stolwijk@rcamsterdam.nl
authors.forename: Janneke M
authors.initials: JM
authors.lastname: Stolwijk-Swüste
authors.forename: Irene
authors.initials: I
authors.lastname: Tersteeg
authors.forename: Anita
authors.initials: A
authors.lastname: Beelen
authors.forename: Gustaaf J
authors.initials: GJ
authors.lastname: Lankhorst
authors.forename: Frans
authors.initials: F
authors.lastname: Nollet
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D011051:Poliomyelitis / Q000503:physiopathology*; D011446:Prospective Studies; D012737:Sex Factors; D013997:Time Factors; D016138:Walking