The modified Barthel Index (mBI) (Shah et al (1989) is a worldwide adopted scale which investigates independence in the basic activities of daily living. It comprises ten items as the original version (personal hygiene, bathing, feeding, toilet, stairs, dressing, bowels, bladder, transfers, ambulation/wheelchair management), with a modification to the scoring to enhance its responsiveness. The mBI has been cross-culturally adapted in several countries and languages, However, despite unofficial versions circulating in clinical settings, there is currently no validated Italian version of the scale. This study aims to develop this version and to evaluate its metric properties in a sample of subjects who had a stroke.
A pre-final mBI-Italian will be produced following established international guidelines (forward-backward translation, each step involving two different translators). This version will be tested in a group of ten health professionals (physicians and physiotherapists), ten subjects who had a stroke and ten caregivers, All participants will be asked to judge the clarity of each item of the scale, including scoring instructions, using a dichotomous response (clear/unclear). Items that are judged unclear by more than 20 percent of evaluators will be revised by the multidisciplinary translation team to produce the final mBI-Italian.
The final mBI-Italian will then be administered to a sample of at least 100 subjects with stroke to assess its metric properties in this population. Participants will be enrolled among patients admitted to the Don Gnocchi Foundation in Florence for stroke rehabilitation. To assess reliability, upon admission each patient will be independently assessed using the mBI-Italian by two examiners, drawn at random from a group of ten physiotherapists. One of the two raters will administer the scale twice on consecutive days. Other evaluators will administer other clinical scales (Fugl-Meyer assessment, FMA; modified Rankin scale, mRS) to assess the validity of the mBI-Italian. All raters will be blinded to all other assessments and to their previous assessment, if any. All the scales will be administered again at discharge, when participants will also be asked to indicate the perceived change since admission in their ability to autonomously manage the basic activities of daily living (ADLs). For the latter, a 7-points Global Rating of Perceived Change (GRPC) Lickert scale will be used.
The Cronbach's alpha will be used to estimate the internal consistency of the scale. To assess intra-rater and inter-rater reliability, the Intraclass Correlation Coefficient (ICC1,1), Standard Error of the Measurement (SEM) and Minimal Detectable Change with 95% Confidence (MDC95) will be computed. Criterion and construct validity will be assessed by computing the association between the mBI-Italian and the FMA and the mRS, at both admission and discharge. For responsiveness, the following indices will be calculated: 1) Guyatt Responsiveness Index (GRI); 2) Standardized Response Mean (SMR), both in the whole sample and in subgroups of participants with different outcome (improved, unchanged, worsened) based on the GPRC; 3) Minimal Clinically Important Difference (MCID). The latter will be derived using the ROC curve approach, using the patient's perceived change in his/her autonomy in basic ADLs as an anchor.
