Psychometrics, diagnostics and usability of Italian tools assessing behavioural and functional outcomes in neurological, geriatric and psychiatric disorders: a systematic review

Background: Psychometric instruments assessing behavioural and functional outcomes (BFIs) in neurological, geriatric and psychiatric populations are relevant towards diagnostics, prognosis and intervention. However, BFIs often happen not to meet methodological-statistical standards, thus lowering their level of recommendation in clinical practice and research. This work thus aimed at (1) providing an up-to-date compendium on psychometrics, diagnostics and usability of available Italian BFIs and (2) delivering evidence-based information on their level of recommendation. Methods: This review was pre-registered (PROSPERO ID: CRD42021295430) and performed according to PRISMA guidelines. Several psychometric, diagnostic and usability measures were addressed as outcomes. Quality assessment was performed via an ad hoc checklist, the Behavioural and Functional Instrument Quality Assessment. Results: Out of an initial N = 830 reports, 108 studies were included (N = 102 BFIs). Target constructs included behavioural/psychiatric symptoms, quality of life and physical functioning. BFIs were either self- or caregiver-/clinician-report. Studies in clinical conditions (including neurological, psychiatric and geriatric ones) were the most represented. Validity was investigated for 85 and reliability for 80 BFIs, respectively. Criterion and factorial validity testing were infrequent, whereas content and ecological validity and parallel forms were almost never addressed. Item response theory analyses were seldom carried out. Diagnostics and norms lacked for about one-third of BFIs. Information on administration time, ease of use and ceiling/floor effects were often unreported. Discussion: Several available BFIs for the Italian population do not meet adequate statistical-methodological standards, this prompting a greater care from researchers involved in their development.