Responsiveness, Minimal Detectable Change, and Minimal Clinically Important Difference of the Nottingham Extended Activities of Daily Living Scale in Patients With Improved Performance After Stroke Rehabilitation

Wu C-Y, Chuang L-L, Lin K-C, Lee S-D, Hong W-H. Responsiveness, minimal detectable change, and minimal clinically important difference of the Nottingham Extended Activities of Daily Living scale in patients with improved performance after stroke rehabilitation. Arch Phys Med Rehabil 2011;92:1281-7. Objectives: To determine the responsiveness, minimal detectable change (MDC), and minimal clinically important differences (MCIDs) of the Nottingham Extended Activities of Daily Living (NEADL) scale and to assess percentages of patients' change scores exceeding the MDC and MCID after stroke rehabilitation. Design: Secondary analyses of patients who received stroke rehabilitation therapy. Setting: Medical centers. Participants: Patients with stroke (N=78). Interventions: Secondary analyses of patients who received 1 of 4 rehabilitation interventions. Main Outcome Measures: Responsiveness (standardized response mean [SRM]), 90% confidence that a change score at this threshold or higher is true and reliable rather than measurement error (MDC90), and MCID on the NEADL score and percentages of patients exceeding the MDC90 and MCID. Results: The SRM of the total NEADL scale was 1.3. The MDC90 value for the total NEADL scale was 4.9, whereas minima and maxima of the MCID for total NEADL score were 2.4 and 6.1 points, respectively. Percentages of patients exceeding the MDC90 and MCID of the total NEADL score were 50.0%, 73.1%, and 32.1%, respectively. Conclusions: The NEADL is a responsive instrument relevant for measuring change in instrumental activities of daily living after stroke rehabilitation. A patient's change score has to reach 4.9 points on the total to indicate a true change. The mean change score of a stroke group on the total NEADL scale should achieve 6.1 points to be regarded as clinically important. Our findings are based on patients with improved NEADL performance after they received specific interventions. Future research with larger sample sizes is warranted to validate these estimates.