title: Continuous NSAID use reverts the effects of inflammation on radiographic progression in patients with ankylosing spondylitis.
abstract: OBJECTIVE
  The aim was to compare continuous and on-demand NSAID treatment with respect to their ability to suppress radiographic progression in subgroups of patients with high/elevated CRP-levels, ESR, ASDAS-levels or BASDAI-levels in comparison to patients with normal levels.
  
  
  METHODS
  Post-hoc analyses were performed in a randomized trial comparing continuous and on-demand NSAID treatment. Relevant high/elevated subgroups were created based on time-averaged (ta) CRP (>5mg/L), ta-ESR (>12mm/hr), ta-BASDAI (>4), ta-ASDAS-CRP (>2.1) and ta-ASDAS-ESR (>2.1). Subgroups were further split according to NSAID-use (continuous vs. on-demand). Radiological progression was presented in probability plots. Statistical interactions were tested using multiple and logistic regression analysis. Differences in radiological progression were analysed using the Chi-square and Mann-Whitney U test.
  
  
  RESULTS
  150 participants randomized to either the continuous-treatment group (n=76), or the on-demand group (n=74) had complete radiographs and were included. The effect of slowing radiological progression with continuous NSAID therapy was more pronounced in patients with elevated ta-CRP-levels, elevated ta-ESR, high ta-ASDAS-CRP or high ta-ASDAS-ESR versus patients with low/normal values. No such effect was found for participants with high vs. low BASDAI. Also, in participants with elevated ta-ESR (irrespective of treatment), there appeared to be a higher rate of structural progression than in participants with normal ta-ESR. Regression analyses showed that continuous NSAID treatment neutralizes the negative effect of inflammation (high ta-ESR).
  
  
  CONCLUSIONS
  Patients with elevated acute phase reactants seem to benefit most from continuous treatment with NSAIDs. Continuous NSAID-therapy in patients with elevated acute phase reactants may lead to an improved benefit-risk-ratio of these drugs.
authors.affiliation: Leiden University Medical Center, Rheumatology, PO Box 9600, 2300 RC Leiden, The Netherlands. mail@dvanderheijde.nl
authors.forename: Féline
authors.initials: F
authors.lastname: Kroon
authors.forename: Robert
authors.initials: R
authors.lastname: Landewé
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
authors.forename: Désirée
authors.initials: D
authors.lastname: van der Heijde
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007249:Inflammation / Q000188:drug therapy*; D008297:Male; D013167:Spondylitis, Ankylosing / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal