Hospital Anxiety and Depression Scale (HADS): Arabic - Vacau

• translations methodology is appropriate;
• reports of internal consistency (although other forms of reliability are highly
desirable);
• factor analysis (preferably confirmatory factor analysis);
• reports of relationships/correlations with theoretically related variables;
• reports of diagnostic validity and sensitivity and specificity.
The rating scale below has been adapted from Rick, Briner et al (2001).
1. Very Good Several validation analyses including several studies
conducted by independent research teams
2. Good More than one validation study, and at least one
validation study conducted by an independent
research team.
3. Promising Additional independent evidence needed. Two or
more studies conducted, but all by research teams
connected to scale developers.
4. Additional
evidence
needed
Only one validation study conducted or one partial
validation study conducted.
5. No full validation studies conducted
RELIABILITY
K. OVERALL EVALUATION OF INTERNAL CONSISTENCY
The internal consistency of scale scores refers to extent to which they are
free of random error. In other words, questions within an instrument that
assess one construct should correlate strongly with other questions that
measure the same construct. Two widely used methods of assessing
internal consistency are coefficient alpha (commonly known as Cronbach’s
alpha) and split half reliability. For a detailed discussion of these measures
the reader is referred to Nunnally and Bernstein (1994). An alpha coefficient
of 0.7 or greater is recommended as a minimal requirement for pooled data
although higher reliabilities would be required when scores inform clinical
judgement.
Each individual study is evaluated using the following criteria, based on the
work of Nunnally (1978) and the rating system of Bickman, Nurcombe et al
(1999).
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