Background Nailfold videocapillaroscopy (VCP) has gained considerable interest by rheumatologists over the past years due its utility in both clinical practice and research, and has become an established method to assess the microcirculation “status” in patients with Raynaud’s phenomenon (RP) and systemic sclerosis (SSc). Although it has been demonstrated that technical skills in VCP can quickly be attained (1), the recognition and interpretation of both the “normal” VCP pattern and the pathological findings, typical of the “scleroderma pattern” (SP), require more time and a more careful standardization.
Objectives To test the learning curve of four rheumatologists with little or no experience in VCP who attended an intensive training programme focused on the interpretation of the normal pattern, the main capillary abnormalities and SP, and to determine the inter-reader agreement compared with an experienced investigator.
Methods Five investigators (1 senior, 1 junior with little experience in VCP and 4 beginners) participated in the exercise. The study consisted of two steps. In the first step, an independent investigator selected representative VCP images of normal patterns and SP patterns. The second step included the training programme that was run for 4 hours per day for seven days. The senior investigator provided the basic knowledge to recognize and interpret the normal pattern, the capillary abnormalities, such as giant capillaries, irregularly enlarged capillaries, micro-haemorrhages, and the different types of SP, according to Maricq (classification A) and Cutolo (classification B) (2,3).
Results A total of 300 VCP images were assessed by all the investigators. Both k-values and overall agreement percentages of qualitative and quantitative assessments showed a progressive improvement, from poor to excellent, from the beginning to the end of the exercise. According to the classification A, the global κ values in the first session were 0.468 for the junior and 0.394, 0.529 and 0.514 for the 1st, 2nd and 3rd beginner respectively, whereas in the last session were 0.812 for the junior and 0.842, 0.844 and 0.794 for the 1st, 2nd and 3rd beginner respectively. For the classification B the global κ values in the first session were 0.349 for the junior and 0.391, 0.398 and 0.397 for the 1st, 2nd and 3rd beginner respectively whereas they were 0.786 for the junior and 0.812, 0.743 and 0.832 for 1st, 2nd and 3rd beginner, respectively, in the last session. Both sensitivity and specificity in the assessment of SP at the last session of reading were high (100% and 86% for the junior; 99% and 79% for the 1st beginner; 99% and 82% for the 2nd beginner; 98% and 79% for the 3rd beginner).
Conclusions Our pilot study suggests that after a short intensive, one-week training programme, novice investigators in VCP are able to correctly assess the normal pattern and the SP achieving good inter-reader agreement rates.
De Angelis R, et al. Clin Exp Rheumatol 2009;27:651-3.
Maricq HR. Arthritis Rheum 1981; 24:1159-65.
Cutolo M, et al. J Rheumatol 2000;27: 155-60.
Disclosure of Interest None Declared