title: BLISS index using WOMAC index detects between-group differences at low-intensity symptom states in osteoarthritis.
abstract: OBJECTIVE
  The ability of the Bellamy et al. Low-Intensity Symptom State-attainment (BLISS) Index to differentiate between treatment groups (hylan G-F 20 vs. appropriate care) at low and very low levels of state attainment in patients with knee osteoarthritis was explored using the stiffness, function, and total index (TI) components of the WOMAC.
  
  
  METHODS
  Six different BLISS measures were analyzed using five WOMAC score thresholds: <or=5 normalized units (NUs): <or=10, <or=15, <or=20, and <or=25 (lower=better health).
  
  
  RESULTS
  More patients in the hylan G-F 20 group achieved BLISS states in all three WOMAC subscales for all six BLISS analyses. These differences were statistically significant for the BLISS response at any time at all threshold levels except </=5NU.
  
  
  CONCLUSIONS
  The six BLISS measures and threshold levels of stiffness, function, and TI score were able to statistically discriminate between treatment groups. BLISS-10 is a therapeutically attainable very low symptom state at which clinically important statistically significant between-group differences are detectable in pain, stiffness, function, and TI score and therefore may provide a benchmark against which therapeutic interventions can be assessed. However, the value to patients of these symptom states requires further elaboration.
authors.affiliation: Centre of National Research on Disability and Rehabilitation Medicine (CONROD), The University of Queensland, Level 3, Mayne Medical School, Herston Road, Brisbane, QLD 4006, Australia. n.bellamy@uq.edu.au <n.bellamy@uq.edu.au>
authors.forename: Nicholas
authors.initials: N
authors.lastname: Bellamy
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Bell
authors.forename: Charlie H
authors.initials: CH
authors.lastname: Goldsmith
authors.forename: Shelley
authors.initials: S
authors.lastname: Lee
authors.forename: Michael
authors.initials: M
authors.lastname: Maschio
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Raynauld
authors.forename: George W
authors.initials: GW
authors.lastname: Torrance
authors.forename: Peter
authors.initials: P
authors.lastname: Tugwell
mesh_terms: D000368:Aged; D001672:Biocompatible Materials / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods; D020127:Recovery of Function; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; C049816:hylan; D006820:Hyaluronic Acid