Psychometric properties of the Benzodiazepine Dependence Self-Report Questionnaire - Portuguese Version (BENDEP-SRQ-PV)

Abstract

Objective: To assess psychometric properties of the Benzodiazepine Dependence Self-Report Questionnaire - Portuguese Version (BENDEP-SRQ-PV) in a sample of Brazilian chronic hypnotic users.

Methods: One hundred and seventy-nine chronic hypnotic users (benzodiazepines and Z-drugs) were recruited, attended a psychiatric evaluation, and answered the BENDEP-SRQ-PV. Factor structure, reliability, and influence of covariates (dependence diagnosis and type of drug consumed) were assessed in a structural equation modelling environment. Discrimination was assessed with receiver operating characteristic (ROC) plots and stability with the test-retest method.

Results: Participants, mostly women (91.6%), aged 51 to 64 years old, had been using hypnotics for an average of 34.8 months, with a mean defined daily dose of 0.72. Psychometric analysis demonstrated construct and criterion validity, reliability, and response stability. The factor structure was maintained as originally proposed: problematic use (ω = 0.73), preoccupation (ω = 0.74), lack of compliance (ω = 0.74), and withdrawal (ω = 0.93).

Conclusion: The BENDEP-SRQ-PV is an adequate measure of hypnotic dependence in the Brazilian population of chronic users. Our results support using the scale for follow-up in clinical and research applications and in correlational studies.

Figure 1. Model 1, a unidimensional model in which all of the BENDEP-SRQ-PV items load onto a single hypnotic dependence factor (BENDEP). Items are numbered as on the questionnaire and represented in rectangles, the latent variable is illustrated by the oval shape, and the standardized factor loadings are shown along the single-headed arrows. BENDEP-SRQ-PV = Benzodiazepine Dependence Self-Report Questionnaire – Portuguese Version.

Figure 2. Model 2, in which all 20 items, represented in rectangles, load onto the specific factors defined by Kan et al. Items are numbered as on the questionnaire and represented in rectangles and the latent variable are illustrated by the oval shapes. Correlations between latent factors are represented along the curved double-headed arrows; standardized factor loadings are shown along the single-headed arrows. LACK = lack of compliance; PREOC = preoccupation; PROB = problematic use; WITHD = withdrawal.

Figure 3. Model 3, based on work by Kan et al.,20 suggesting that withdrawal (WITHD) symptoms could constitute a separate dimension of hypnotic dependence. Problematic use (PROB), preoccupation (PRE), and lack of compliance (LACK) are grouped in a second-order hierarchical factor named psychosocial signs of dependence (PSY). Withdrawal was maintained as a first-order factor (physical signs of dependence). Items are numbered as on the questionnaire and represented in rectangles and the latent variables are illustrated by the oval shapes. Correlations between latent factors are represented along the curved double-headed arrows; standardized factor loadings are shown along the single-headed arrows.