Responsiveness and minimum important change of the Oswestry Disability Index in Italian subjects with symptomatic lumbar spondylolisthesis

Journal of Orthopaedics and Traumatology

Official Journal of the Italian Society of Orthopaedics and Traumatology

Table 3 Responsiveness of NRS and ODI-I

Method	Value	Improved	Not improved
Method	Total	Improved	Not improved
NRS
Minimum detectable change	9.77	7.98	9.75
Effect size	1.15	1.29	0.65
Effect size (Guyatt)	1.25	1.41	0.65
Standardized response mean	1.21	1.38	0.65
Optimal cut-off point (AUC, sensitivity, specificity)	17.5 (0.85, 90.3, 37.5)
ODI-I
Minimum detectable change	5.72	4.23	8.14
Effect size	1.0	0.95	0.15
Effect size (Guyatt)	0.87	0.86	0.15
Standardized response mean	1.0	1.25	0.17
Optimal cut-off point (AUC, sensitivity, specificity)	7.5 (0.76, 90.3, 56.7)

ODI-I Oswestry Disability Index (Italian version), NRS numerical rating scale