Background Ultrasonography (US) is an important tool in rheumatology practice but it depends on sonographer's experience.
Objectives To evaluate the reliability of US assessment among observers across Latin American using a web tool.
Methods Cross-sectional study. Fifty-one Latin American ultrasonographers took part in a web- based US exercise evaluating images from 20 RA patients. The 4 joints US score was calculated for each patient including bilateral radiocarpal, midcarpal and second metacarpophalangeal joints. PD and GS were graded from 0 to 3. US scores comes as the result of the addition of PD and GS score, being 36 the highest disease activity.
Five patients were evaluated twice in order to address intra – rater reliability. The inter and intra-rater reliability was assessed using a two-way random, absolute, individual and average-measures intra-class correlation coefficient (ICC). We stratified sonographers according to experience (defining High experience as: at least 5 years of experience and 80 US assessments/month).
Results A total of 1020 US image assessments were performed. Mean 4-joints US score was 17±8. The ICC was in the excellent range for intra [(individual ICC = 0.945 (IC95% 0.905–0.965); average ICC =0.972 (IC95% 0.950–0.982)] and inter- reader reliability [(individual ICC =0.867 (IC95% 0.786–0.934); average ICC = 0.997 (IC95% 0.995–0.999)].
When comparing high with low experience sonographers, there was no significant differences in intra-class correlation coefficient. However, there was a greater variation between the means among low experience readers (13 to 22) and higher experience sonographers (14–18) (Figure 1).
Conclusions US reliability is related to sonographer expertise and experience.
Acknowledgements Edith Alarcόn, Lucio Ventura, Walter J. Spindler, Christina Hernandez-Diaz, Javier Rosa, Santiago Ruta, Mara Guinsburg, Gustavo Rodriguez Gil, Cecilia Urquiola, Guillermo Py, Magalí Alva, Patricio Tate, Carmen Cerόn, Lida Santiago, Ana Laura Alvarez del Castillo Araujo, Maria Jezabel Haye Salinas, Erika Catay, Maximiliano Bravo, Johana Zacariaz, Clarisa Sandobal, Gonzalo Pacheco, Mariana Benegas, David Navarta, Verόnica Arturi, Ana Bertoli, Marcelo Audisio, Carlos Pineda, Natalia Estrella, Carla Airoldi, Paula Kohan, María Julia Santa Cruz, Lina Saldarriaga Rivera, Romulo Wong, Ignacio Carrillo, Hugo Najera, Julio García, Daniele Freitas Pereir, Fernanda Athayde Cardoso Linhares, José Alexandre Mendonça, Maritza Quintero, Anthony M. Reginato, Eliana Natalí Ayala Ledesma, Lorena Urioste, Eugenio De Miguel, María Soledad Gálvez Elkin, Carla Saucedo, Josefina Marin, Rodolfo Arape, Marwin Gutierrez.
Disclosure of Interest None declared