’Less is more’: validation with Rasch analysis of five short-forms for the Brain Injury Rehabilitation Trust Personality Questionnaires (BIRT-PQs)

ABSTRACT

Background

Previous analyses demonstrated a lack of unidimensionality, item redundancy, and substantial administrative burden for the Brain Injury Rehabilitation Trust Personality Questionnaires (BIRT-PQs).

Objective

To use Rasch Analysis to calibrate five short-forms of the BIRT-PQs, satisfying the Rasch model requirements.

Methods

BIRT-PQs data from 154 patients with severe Acquired Brain Injury (s-ABI) and their caregivers (total sample = 308) underwent Rasch analysis to examine their internal construct validity and reliability according to the Rasch model.

Results

The base Rasch analyses did not show sufficient internal construct validity according to the Rasch model for all five BIRT-PQs. After rescoring 18 items, and deleting 75 of 150 items, adequate internal construct validity was achieved for all five BIRT-PQs short forms (model chi-square p-values ranging from 0.0053 to 0.6675), with reliability values compatible with individual measurements.

Conclusions

After extensive modifications, including a 48% reduction of the item load, we obtained five short forms of the BIRT-PQs satisfying the strict measurement requirements of the Rasch model. The ordinal-to-interval measurement conversion tables allow measuring on the same metric the perception of the neurobehavioral disability for both patients with s-ABI and their caregivers.

KEYWORDS:

• Brain injuries
• behavioral symptoms
• personality assessment
• outcome assessment
• health care
• psychometrics
• rehabilitation

Acknowledgments

The authors want to thank Elisa Scarano and Maria Daniela Lo Sapio for their help in collecting the data.

Data availability statement

The data that support the findings of this study may be downloaded from https://www.dropbox.com/sh/dzq85x14yovrlej/AAD4HHb3meoJue7Nyk4sgng_a?dl=0.

Disclosure statement

The authors report no conflict of interest

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

LP was (partially) supported by the Italian Ministry of Health (Ricerca Corrente)