Arabic Behçet’s Disease Quality of Life Questionnaire

Authors

Purpose

The primary objective of adapting the BD-QoL into Arabic is to provide clinicians and researchers with a disease-specific metric that accurately reflects the lived experience of Arabic-speaking patients with Behçet's disease. While generic Quality of life instruments are widely used in Rheumatology, they often lack the sensitivity required to detect nuanced clinical changes in conditions with highly specific symptom profiles. By utilizing a targeted tool, healthcare providers can better understand how unique manifestations, such as oral ulcers or visual impairments, interfere with daily functioning and emotional well-being.

Furthermore, establishing a psychometrically sound Arabic version facilitates cross-cultural comparative research. It allows for the inclusion of Middle Eastern populations in global clinical trials, ensuring that outcome measures are not confounded by language barriers or cultural misunderstandings. This ultimately supports more personalized and effective patient care strategies.

Construct

The psychological and functional construct measured by the BD-QoL is disease-specific Health-Related Quality of Life (HRQoL). In the context of Behçet's disease, HRQoL encompasses the physical limitations, emotional distress, and social participation restrictions directly resulting from the illness. Unlike objective indices of disease severity, which tally the presence of physical lesions or organ involvement, this construct captures the subjective appraisal of how these symptoms disrupt the individual's life trajectory.

The Arabic adaptation of the scale operates on a unidimensional framework, meaning that all items contribute to a single, overarching latent trait of disease-related life quality. The items span various domains of daily living, including mobility challenges, psychological worries about the future, self-esteem issues related to physical appearance, and the perceived burden placed on interpersonal relationships.

Validity

To establish the construct validity of the Arabic BD-QoL, researchers examined its relationship with established measures of functional impairment and clinical severity. Convergent validity was demonstrated through a moderate, positive correlation with a standardized clinical severity score (r = 0.40). This magnitude of association is theoretically expected in rheumatological research, as subjective Quality of life and objective disease activity are related but distinct constructs; patients may develop coping mechanisms that buffer their Quality of life even when disease severity is high.

Additionally, the scale's external validity was supported by its associations with functional independence metrics. The Arabic BD-QoL correlated significantly with the Instrumental Activities of Daily Living (IADL) scale, indicating that higher disease-specific burden aligns with greater difficulties in managing complex daily tasks. The rigorous multi-stage translation process, which included bilingual expert committees and patient pre-testing, further ensured robust content and face validity across cultural boundaries.

Convergent & Discriminant Validation Correlations

Reliability

The psychometric evaluation of the Arabic BD-QoL revealed excellent reliability metrics, indicating that the tool measures the underlying construct with high precision and consistency. Because the scale utilizes a dichotomous response format, internal consistency was evaluated using the Kuder-Richardson Formula 20 (KR-20), yielding a strong coefficient of 0.89. This value comfortably exceeds the standard threshold of 0.70 recommended for research and clinical instruments, confirming that the 30 items are highly interrelated and reliably capture the same overarching Quality of life construct.

Temporal stability was also rigorously assessed to ensure the scale's utility in longitudinal monitoring. Test-retest reliability, evaluated via Spearman's rank correlation coefficient, was exceptionally high at 0.91. This demonstrates that patient scores remain stable over short periods when their clinical status has not changed, making the Arabic BD-QoL a dependable tool for tracking disease progression or evaluating the efficacy of therapeutic interventions over time.

Factor Analysis

The dimensionality of the Arabic BD-QoL was investigated using Exploratory Factor Analysis (EFA). The analytical objective was to determine whether the translated items clustered into distinct sub-domains or loaded onto a single primary factor. The results of the EFA indicated a convergence of all 30 items, strongly supporting a unidimensional structure for the adapted scale. This aligns with the theoretical conceptualization of the instrument as a holistic measure of disease-specific Quality of life.

It is important to note, however, that the factor analysis was conducted on a relatively small sample size of 41 patients. In psychometric literature, EFA typically requires larger subject-to-variable ratios to ensure the stability of factor loadings. While the unidimensional finding is consistent with the original English version of the scale, researchers acknowledge this sample size limitation and recommend that future studies with larger, multi-center cohorts conduct Confirmatory Factor Analysis (CFA) to further validate the structural integrity of the Arabic instrument.

Instrument

Scoring & Interpretation Guidelines

Arabic Behçet's Disease Quality of Life Questionnaire Items

Sample

The study sample consisted of 41 consecutive Lebanese patients diagnosed with Behçet's disease attending Rheumatology clinics at the American University of Beirut Medical Center. The sample included 24 males and 17 females, with a mean age of 34 years (SD = 11).

Permissions & Test Year

Permission to use and adapt the scale was granted by the developers of the original Leeds BD-QoL questionnaire.

Test Year: 2011