Table 1

First and second survey of proficiency testing in Italy (1998–1999 and 2000 respectively)

Drug	First survey, 1998/1999			Second survey, 2000
Drug	Value	Min	Max	Value	Min	Max
INH
Sensitivity	93.2	29	100	96.3	56	100
Specificity	98.5	100	100	98.8	75	100
PVR	99.0	93	100	99.7	94	100
PVS	91.0	38	100	92.5	36	100
Efficiency	94.8	50	100	96.8	65	100
Reproducibility	95.0	80	100	96.5	80	100
RMP
Sensitivity	94.9	70	100	94.0	50	100
Specificity	98.6	89	100	96.5	50	100
PVR	98.6	89	100	97.4	67	100
PVS	96.2	77	100	95.2	67	100
Efficiency	96.7	85	100	95.3	75	100
Reproducibility	95.1	70	100	95.5	90	100
SM
Sensitivity	87.7	20	100	91.9	75	100
Specificity	96.3	78	100	89.2	58	100
PVR	96.2	82	100	87.5	58	100
PVS	91.4	56	100	94.8	83	100
Efficiency	91.7	60	100	90.3	70	100
Reproducibility	90.6	75	100	90.5	60	100
EMB
Sensitivity	85.5	0	100	88.8	17	100
Specificity	93.8	75	100	97.5	75	100
PVR	91.4	67	100	98.5	86	100
PVS	94.1	70	100	90.6	44	100
Efficiency	91.3	70	100	92.3	50	100
Reproducibility	86.9	60	100	93.0	70	100

All data are presented as per cent
PVR: positive value of a resistant result
PVS: positive value of a susceptible result
INH: isoniazid
RMP: rifampicin
SM: streptomycin
EMB: ethambutol