Karpouzas George A, Strand Vibeke, Ormseth Sarah R
Division of Rheumatology, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California, USA.
Division of Immunology/Rheumatology, Stanford University School of Medicine, Palo Alto, California, USA.
RMD Open. 2018 Jun 28;4(1):e000695. doi: 10.1136/rmdopen-2018-000695. eCollection 2018.
Patients and physicians commonly differ in their assessments of rheumatoid arthritis (RA) activity. Clinically meaningful discordance thresholds or validation of their ability to predict functional outcomes are lacking. We explored whether an unbiased, person-centred latent profile analysis (LPA) approach could classify cases based on patient global assessment (PtGA) and physician global assessment (MDGA) assessments of RA activity. We further examined whether the LPA groups displayed greater differences in clinical outcomes compared with traditional threshold-based groups. Finally, we evaluated whether LPA yielded higher explanatory power for clinical outcomes.
LPA was performed in 618 patients with established RA from a single centre. A threshold-based discordance definition was used as a comparator, with patients classified into concordant (PtGA-MDGA within ± 3 cm), positively discordant (PtGA-MDGA ≥3 cm) and negatively discordant groups (PtGA-MDGA ≤-3 cm).
LPA yielded five distinct groups: low PtGA/low MDGA (35.9%), moderate PtGA/moderate MDGA (18.6%), high PtGA/high MDGA (14.7%), high PtGA/low MDGA (23.3%) and low PtGA/high MDGA (7.4%). Groups differed across clinical, physical function, pain, fatigue, health-related quality of life, work productivity and activity impairment outcomes (p<0.001). Concordance groups, in particular, displayed marked heterogeneity in outcomes depending on the magnitude of disease activity reported, with the low/low group faring the best (p<0.001). The LPA solution demonstrated superior explanatory power for all outcomes (p<0.001).
We confirmed the validity and advantages of LPA in characterising the relationship between PtGA and MDGA over a conventional threshold-based definition. LPA yielded optimally distinct, clinically meaningful and cohesive groupings, demonstrating superior explanatory power for disease-related outcomes of interest.
患者与医生对类风湿关节炎（RA）活动度的评估通常存在差异。目前缺乏具有临床意义的不一致阈值或对其预测功能结局能力的验证。我们探讨了一种无偏倚的、以患者为中心的潜在剖面分析（LPA）方法是否能够根据患者整体评估（PtGA）和医生整体评估（MDGA）对RA活动度的评估对病例进行分类。我们进一步研究了与传统的基于阈值的分组相比，LPA分组在临床结局上是否表现出更大的差异。最后，我们评估了LPA对临床结局是否具有更高的解释力。
对来自单一中心的618例确诊RA患者进行LPA。将基于阈值的不一致定义用作对照，患者被分为一致组（PtGA - MDGA在±3 cm范围内）、正不一致组（PtGA - MDGA≥3 cm）和负不一致组（PtGA - MDGA≤ - 3 cm）。
LPA产生了五个不同的组：低PtGA/低MDGA（35.9%）、中度PtGA/中度MDGA（18.6%）、高PtGA/高MDGA（14.7%）、高PtGA/低MDGA（23.3%）和低PtGA/高MDGA（7.4%）。各组在临床、身体功能、疼痛、疲劳、健康相关生活质量、工作生产力和活动障碍结局方面存在差异（p<0.001）。特别是一致组，根据报告的疾病活动度大小，结局显示出明显的异质性，低/低组情况最佳（p<0.001）。LPA解决方案对所有结局均显示出更高的解释力（p<0.001）。
我们证实了LPA在描述PtGA和MDGA之间关系方面相对于传统基于阈值的定义的有效性和优势。LPA产生了最优的、不同的、具有临床意义且连贯的分组，对感兴趣的疾病相关结局显示出更高的解释力。
