Table 3

Further analysis of the data using simple variables, for example, providing rheumatologic assessment to only those AAU patients who have backache or human leucocyte antigen (HLA)-B 27 positive, on their own or in different combinations, and their performance to improve the detection of underlying spondyloarthritis (SpA)

 Performance Improvement of DUET algorithm using different variables
Sensitivity (%)Specificity (%)PPV (%)NPV (%)Positive
HLA B 27+9074.572923.550.12
HLA B 27+ and backache909592.693.317.790.10
Backache (age of onset <45 years) and HLA B 27+90989793.553.380.09
Test algorithm10054611002.180.00
DUET algorithm959897.596.656.190.04
  • AAU, acute anterior uveitis; NPV, negative predictive value; PPV, positive predictive value; LR, likelihood ratio.