Intra- and inter-tester reliability of sensibility testing in leprosy

We conducted an intra- and inter-tester agreement study of three sensory screening tests used in nerve function assessment of leprosy patients: the Semmes-Weinstein monofilament (SWM) test, moving 2-point discrimination (M2PD), and the pin prick test. The weighted kappa (Kw) statistic was used as the reliability coefficient. The SWM had intra-observer Kws ranging from 0.83 to 0.92 and inter-observer Kws ranging from 0.76 to 0.89. The M2PD had intra- and inter-tester Kws ranging from 0.75 to 0.82 and 0.54 to 0.82, respectively. Inter-tester agreement for the pin prick test ranged from 0.45 to 0.85. There was evidence that the main source of variability between testers was testing skill and experience. Among the experienced physiotechnicians there was no significant difference between intra- and inter-tester reliability. We conclude that reliability of the SWM test was very good, closely followed by the M2PD test. Reliability of the pin prick test was less good than that of the SWM and M2PD, making it less suitable for serial testing.