Building consensus on nomenclature and disease classification for ankylosing spondylitis: results and discussion of a questionnaire prepared for the International Workshop on New Treatment Strategies in Ankylosing Spondylitis, Berlin, Germany, 18-19 January 2002

Abstract

Background: There is currently no universal consensus on nomenclature for spondyloarthropathy (SpA), or on activity and severity criteria for ankylosing spondylitis (AS).

Method: Points of agreement and majority opinions among 28 international experts in the field were identified by questionnaire. Agreement was defined as >80% concurrence, clear majority as >60% concurrence, and a majority or trend as >50% concurrence.

Results: Respondents agreed on the need for one term that reflects the inflammatory nature of the disease, but no agreement was reached on a specific term. Agreement included subdivision of patients with SpA into AS, psoriatic arthritis, inflammatory bowel disease associated arthritis, and undifferentiated spondyloarthritis/spondyloarthropathy. A majority of experts defined active disease as fulfilling classification criteria for AS and/or a SpA, and disease activity measured by a Bath AS Disease Activity Index (BASDAI) score >4 determined by two patient visits during a two month period, but no maximum radiographic score. The majority of participants considered failure of treatment response to non-steroidal anti-inflammatory drugs (NSAIDs) alone to be a prerequisite for active/severe AS, and 15/28 (54%) thought that NSAID treatment failure should be defined as lack of response to two or more NSAIDs.

Conclusions: Respondents agreed that a two to five year study is the ethical method to demonstrate effects of anti-tumour necrosis factor alpha (TNFalpha) therapy on radiographic progression of AS, and that inclusion criteria should include a certain level of disease activity (measured by BASDAI) and failure of certain treatments. After the efficacy of anti-TNFalpha therapy in AS and psoriatic arthritis is proved, respondents agreed that more studies will be needed to show efficacy for other SpA subsets.

Figure 1

Respondents' preferences for the terms "spondyloarthritis" and "spondyloarthropathy."

Figure 2

Percentages of respondents choosing to (a) abandon the term "Reiter's disease"; (b) use the term "reactive arthritis"; (c) use only the term, "Reiter's disease" in reference to the classic triad of arthritis, urethritis, and conjunctivitis; or (d) not change the terminology.

Figure 3

Percentages of respondents preferring the term "severe," "active," or refractory" ankylosing spondylitis in the context of indication for anti-TNF treatment.

Figure 4

Percentages of respondents in favour of BASDAI scores >3, >4, >5, or >6 for definition of active/severe AS.

Figure 5

Percentages of respondents in favour of duration of raised BASDAI scores for at least two or at least three office visits. No respondent voted for more than three visits.

Figure 6

Distribution of responses to question about the duration of raised BASDAI scores at presentation.

Figure 7

Percentages of respondents in favour of (Yes) and against (No) the requirement of raised CRP for definition of active/severe AS.

Figure 8

Percentages of respondents supporting failure of NSAID treatment alone to be sufficient for definition of active/severe AS.

Figure 9

Percentages of respondents in favour of failure of >2 NSAIDs, >3 NSAIDs, maximal NSAID dose, or any NSAID dose as a prerequisite for definition of active/severe AS.

Figure 10

Percentages of respondents in favour of (Yes) and against (No) failure of treatment with other DMARDs as a prerequisite for classification as active/severe AS.

Figure 11

Disagreement among respondents as to whether failure of sulfasalazine should be a prerequisite for classification as active/severe AS.