Assessment of disease activity in patients with rheumatoid arthritis using optical spectral transmission measurements, a non-invasive imaging technique.

OBJECTIVES: In rheumatoid arthritis (RA), treat-to-target strategies require instruments for valid detection of joint inflammation. Therefore, imaging modalities are increasingly used in clinical practice. Optical spectral transmission (OST) measurements are non-invasive and fast and may therefore have benefits over existing imaging modalities. We tested whether OST could measure disease activity validly in patients with RA. METHODS: In 59 patients with RA and 10 patients with arthralgia, OST, joint counts, Disease Activity Score (DAS) 28 and ultrasonography (US) were performed. Additionally, MRI was performed in patients with DAS28<2.6. We developed and validated within the same cohort an algorithm for detection of joint inflammation by OST with US as reference. RESULTS: At the joint level, OST and US performed similarly inproximal interphalangeal-joints (area under the receiver-operating curve (AUC) of 0.79, p<0.0001) andmetacarpophalangeal joints (AUC 0.78, p<0.0001). Performance was less similar in wrists (AUC 0.62, p=0.006). On the patient level, OST correlated moderately with clinical examination (DAS28 r=0.42, p=0.001), and US scores (r=0.64, p<0.0001). Furthermore, in patients with subclinical and low disease activity, there was a correlation between OST and MRI synovitis score (RAMRIS (Rheumatoid Arthritis MRI Scoring) synovitis), r=0.52, p=0.005. CONCLUSIONS: In this pilot study, OST performed moderately in the detection of joint inflammation in patients with RA. Further studies are needed to determine the diagnostic performance in a new cohort of patients with RA.

Economic evaluation of a tight-control treatment strategy using an imaging device (handscan) for monitoring joint inflammation in early rheumatoid arthritis.

OBJECTIVES: To evaluate the cost-effectiveness of a tight-control treatment strategy using the handscan (TCHS) compared to using only clinical assessments (TC) and compared to a general non-tight-control treatment strategy (usual care; UC) in early rheumatoid arthritis (RA). METHODS: Data from 299 early RA patients from the CAMERA trial were used. Clinical outcomes were extrapolated to Quality Adjusted Life Years (QALYs) and costs using a Markov model. Costs and QALYs were compared between the TC and UC treatment strategy arm of the CAMERA trial and a simulated tight-control treatment strategy using the handscan (TCHS). Incremental Cost-Effectiveness Ratios (ICERs) were calculated and several scenario analyses performed. All analyses were performed probabilistically to obtain confidence intervals and costs-effectiveness planes and acceptability curves. RESULTS: In TCHS, €4,660 (95% CI -€11,516 to €2,045) was saved and 0.06 (95% CI 0.01 to 0.11) QALYs were gained when compared to UC, with an ICER of €77,670 saved per QALY gained. Ninety-one percent (91%) of simulations resulted in less costs and more QALYs. TCHS resulted in comparable costs or even limited savings €642 (95% CI -€6,903 to €5,601)) and comparable QALYs to TC. In all scenario analyses, TCHS and TC were found to be cost effective as compared to UC. CONCLUSIONS: A tight-control treatment strategy is highly cost-effective compared to a non-tight-control approach in early RA. Using the handscan as a monitoring device might facilitate implementation of tight-control treatment strategy at comparable costs and with comparable effects. This approach should be investigated further.