Re-examining the factor structure of the Insomnia Severity Index (ISI) and defining the meaningful within-individual change (MWIC) for subjects with insomnia disorder in two phase III clinical trials of the efficacy of lemborexant.
J Patient Rep Outcomes
; 8(1): 65, 2024 Jun 29.
Article
en En
| MEDLINE
| ID: mdl-38951287
ABSTRACT
BACKGROUND:
The Insomnia Severity Index (ISI) is a widely used measure of insomnia severity. Various ISI research findings suggest different factor solutions and meaningful within-individual change (MWIC) to detect treatment response in patients with insomnia. This study examined an ISI factor solution and psychometric indices to define MWIC in a robust patient sample from clinical trial settings.METHODS:
We endeavored to improve upon previous validation of ISI by examining structural components of confirmatory factor analysis (CFA) models using two large, placebo-controlled clinical trials of lemborexant for insomnia. Using the best-fitting two-factor solution, we evaluated anchor-based, distribution-based and receiver operating characteristic (ROC) curve methods to derive an estimate of the MWIC.RESULTS:
The model structure for the 7-item scale proposed in other research did not fit the observed data from our two lemborexant clinical trials (N = 1956) as well as a two-factor solution based on 6 items did. Using triangulation of anchor-based, distribution-based, and ROC methods, we determined that a 5-point reduction using 6 items best represented a clinically meaningful improvement in individuals with insomnia in our patient sample.CONCLUSIONS:
A 6-item two-factor scale had better psychometric properties than the 7-item scale in this patient sample. On the 6-item scale, a reduction of 5 points in the ISI total score represented the MWIC. Generalizability of the proposed MWIC may be limited to patient populations with similar demographic and clinical characteristics.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Psicometría
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Índice de Severidad de la Enfermedad
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Trastornos del Inicio y del Mantenimiento del Sueño
Límite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Patient Rep Outcomes
/
J. patient rep. outcomes
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Journal of patient-reported outcomes
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos