This month I have selected 4 articles published in The Journal of Rheumatology during the 1990s that I feel are worthy of a second look by our readers. I have selected 4 articles, rather than my customary 3, as 2 of the articles are related and were published in the same issue of The Journal as companion articles from the same group and address measurements in ankylosing spondylitis. The companion articles are the original descriptions of the Bath Ankylosing Spondylitis Functional Index (BASFI) by Calin et al1 and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) by Garrett et al,2 both of which have been standard measures for patients with spondyloarthritis (SpA). The other 2 articles are (1) a validation study by Clements et al3 showing that the modified Rodnan total skin thickness score is a valid and reliable measurement instrument to measure skin thickness, which is still used in clinical practice and for research studies in systemic sclerosis; and (2) classification criteria for adult-onset Still’s disease by Yamaguchi et al,4 which are still used today.

The article, “A New Approach to Defining Functional Ability in Ankylosing Spondylitis: The Development of the Bath Ankylosing Spondylitis Functional Index,”1 and the accompanying article, “A New Approach to Defining Disease Status in Ankylosing Spondylitis: The Bath Ankylosing Spondylitis Disease Activity Index”2 were published back-to-back in the same issue of The Journal. Both indices are still used today in both clinical practice and for research studies. In the first paper, Calin et al1 showed that the BASFI was a reliable index that was sensitive to change. It was developed by physicians and physiotherapists with input from patients with SpA, and it was quick and easy to use by patients. As a result of these attributes, the BASFI superseded a previously validated function measure5 and is still in use today. The second paper, by Garrett et al,2 described the BASDAI, which was the first self-administered instrument to define disease activity in patients with SpA. Similar to the BASFI, the BASDAI was developed by a multidisciplinary team consisting of physicians, physiotherapists, and patients. It consists of 6 questions relating to the 5 major symptoms, which are fatigue, spinal pain, joint pain/swelling, areas of localized tenderness, and morning stiffness using anchored visual analog scales. The BASDAI was shown to have the same attributes as the BASFI of being quick, easy to use, and consisting of nonredundant questions. It showed good reliability and was sensitive to change. It rapidly surpassed the measures used up until the time of its publication.6,7

The third article from the 1990s to highlight, “Inter and Intraobserver Variability of Total Skin Thickness Score (Modified Rodnan TSS) in Systemic Sclerosis,”3 was an update of the original Rodnan total skin thickness score (TSS).8 The aim of the study was to simplify the original Rodnan skin score. The study showed that modified Rodnan (mRodnan) TSS was reproducible, with good inter- and intraobserver variability, and correlated well with the more extensive Rodnan TSS. The authors hypothesized that the mRodnan TSS could be used as an outcome measure in clinical studies and for monitoring disease in clinical practice. Both have shown to be true as it is currently used in both settings (now known as modified Rodnan skin score [mRSS]).

The final article I wish to highlight, “Preliminary Criteria for Classification of Adult Still’s Disease,”4 was the first to define classification criteria for what is now referred to as adult-onset Still disease (AOSD). It examined the sensitivity and specificity of both clinical and laboratory features in 90 cases of AOSD (as defined by an expert panel of 11 Japanese rheumatologists) and compared these features to 267 patients with clinical disease that the panel felt could be confused with AOSD. In the initial analysis, they proposed 8 clinical and laboratory items that were divided into major criteria, minor criteria, and exclusions. The criteria were then assessed in 53 additional patients with AOSD and 164 controls. The final classification criteria, which required ≥ 5 criteria, including ≥ 2 major criteria, showed a sensitivity of 96% and specificity of 92%. Similar to other classification criteria, the criteria were proposed to be used by studies for classification but are frequently used for clinical diagnosis. The Yamaguchi criteria is still used today in many studies, although some studies have used the Fautrel criteria.9 A study from 2018 compared the Yamaguchi and Fautrel criteria in 54 patients with AOSD and 278 control patients.10 This study showed that the Yamaguchi had better sensitivity and specificity than the Fautrel criteria, with sensitivities of 96.3% and 87%, respectively, and specificities of 98.9% and 97.8%, respectively. Similarly, comparisons of positive predictive values (Yamaguchi, 94.5% vs Fautrel, 88.7%) and negative predictive values (Yamaguchi, 99.3% vs Fautrel, 97.5%) both tended to favor the Yamaguchi criteria.

I encourage you to read all 4 articles for their current and historic value.