Minimal clinically important difference for the Rasch neuropsychiatric inventory irritability and aggression scale for traumatic brain injury
Publications
Model System:
TBI
Reference Type:
Journal article
Accession No.:
J79034
Journal:
Archives of Physical Medicine and Rehabilitation
Year, Volume, Issue, Page(s):
, 99, 3, 603-606, 606.e1
Publication Website:
Abstract:
Study determined the minimal clinically important difference (MCID) for a Rasch measure derived from the irritability and aggression subscales of the Neuropsychiatric Inventory (NPI), the Rasch NPI Irritability and Aggression Scale for Traumatic Brain Injury (NPI-TBI-IA). Distribution-based statistical methods were applied to retrospective data to determine candidates for the MCID. These candidates were evaluated by anchoring the NPI-TBI-IA to Global Impression of Change (GIC) ratings by participants, significant others, and a supervising physician. Observer ratings on the NPI-TBI-IA in 274 cases and 232 cases with self-ratings by participants with moderate-severe TBI at least 6 months postinjury were converted to a Rasch 0-to-100 metric. For observer ratings on the NPI-TBI-IA, anchored comparisons found an improvement of 0.5 standard deviation (SD) was associated with at least minimal general improvement on GIC by a significant majority (69 to 80 percent); 0.5 SD improvement on participant NPI-TBI-IA self-ratings was also associated with at least minimal improvement on the GIC by a substantial majority (77 to 83 percent). The percentage indicating significant global improvement did not increase markedly on most ratings at higher levels of improvement on the NPI-TBI-IA. Results indicate a 0.5 SD improvement on the NPI-TBI-IA indicates the MCID for both observer and participant ratings on this measure.
