Developing Item Response Theory-Based Short Forms to Measure the Social Impact of Burn Injuries

Abstract

Objective: To develop self-reported short forms for the Life Impact Burn Recovery Evaluation (LIBRE) Profile.

Design: Short forms based on the item parameters of discrimination and average difficulty.

Setting: A support network for burn survivors, peer support networks, social media, and mailings.

Participants: Burn survivors (N=601) older than 18 years.

Interventions: Not applicable.

Main outcome measures: The LIBRE Profile.

Results: Ten-item short forms were developed to cover the 6 LIBRE Profile scales: Relationships with Family & Friends, Social Interactions, Social Activities, Work & Employment, Romantic Relationships, and Sexual Relationships. Ceiling effects were ≤15% for all scales; floor effects were <1% for all scales. The marginal reliability of the short forms ranged from .85 to .89.

Conclusions: The LIBRE Profile-Short Forms demonstrated credible psychometric properties. The short form version provides a viable alternative to administering the LIBRE Profile when resources do not allow computer or Internet access. The full item bank, computerized adaptive test, and short forms are all scored along the same metric, and therefore scores are comparable regardless of the mode of administration.

Keywords: Burn injury; Item response theory; Outcome measurement; Psychometrics; Questionnaires; Rehabilitation.