# Psychometric Validation and Arabic Translation of the 11-Item Circadian Type Inventory (CTI-11A) Among Shift Workers

## TL;DR

This study translated and validated a circadian preference tool for Arabic speakers, finding it reliable and linked to sleep quality differences.

## Contribution

The CTI-11A is a newly validated Arabic version of a circadian preference inventory with psychometric evaluation in a shift worker population.

## Key findings

- The CTI-11A demonstrated good reliability and a valid two-factor structure in Arabic-speaking shift workers.
- Two distinct circadian profiles were identified, with one associated with poorer sleep quality.
- The CTI-11A correlated moderately with sleep disturbance scores, suggesting practical relevance.

## Abstract

Circadian rhythm disruptions from shiftwork impact sleep quality and work performance, yet validated tools to assess circadian preferences in Arabic-speaking populations are scarce. This study aimed to translate and validate the 11-item Circadian Type Inventory (CTI-11) into Arabic (CTI-11A), evaluate its psychometric properties, and explore latent circadian profiles in relation to sleep quality. A cross-sectional survey in Bahrain involved 468 Arabic-speaking adults recruited via social media. The CTI-11A, assessing Languid/Vigorous (LV) and Flexible/Rigid (FR) subscales, and the Jenkins Sleep Scale (JSS) were administered. Confirmatory factor analysis (CFA), reliability tests, and latent class analysis (LCA) were conducted. Participants (mean age: 36.18 ± 10.35) showed CTI-11A total scores of 35.40 ± 6.61 and JSS scores of 5.76 ± 3.48. CFA confirmed the two-factor structure (RMSEA = 0.06, SRMR = 0.05, CFI = 0.93, TLI = 0.91), with Cronbach’s α of 0.72 (total CTI-11A). Test–retest reliability was high (ICC = 0.91). CTI-11A correlated moderately with JSS (r = 0.40, p < 0.001), with stronger FR-JSS (r = 0.36) than LV-JSS (r = 0.25) associations. LCA identified two classes (Class 1: 52%, vigorous/flexible; Class 2: 48%, languid/rigid), with Class 2 showing poorer sleep quality. The CTI-11A is a reliable and valid tool for assessing circadian preferences in Arabic-speaking populations, with distinct circadian profiles linked to sleep quality. While flexible/vigorous profiles associated with better sleep, languid/rigid profiles indicate higher sleep disturbance risk, informing targeted shiftwork interventions. Further refinement of the factor structure and broader regional validation are needed.