| SPHERE-21 | BDI |
---|---|---|
Number of items | 14 (for anxiety-depression) | 21 |
Short form for clinical use | SPHERE-12 (six items for anxiety-depression) | BDI-11 |
IRT requirements | Monotonicity verified Good correlation of items with the latent trait | Monotonicity breached for items 9 and 10 Poor correlation of item 19 with the latent trait [53] |
Sex DIF | Limited (DIFÂ <Â 0.25) | Large DIF for item 14 (DIFÂ =Â 0.32) Limited otherwise (DIFÂ <Â 0.25) [53] |
Age group DIF | Limited (DIF < 0.25); comparable construct from age 9 to 28 years | Not tested at item level (IRT) Not investigated in a population sample Comparable structure and internal consistency (Cronbach’s alpha) for adolescent inpatients [98] |
Language(s) | Arabic, Cantonese, Croatian, Dutch, English, Greek, Italian, Japanese, Mandarin, Portuguese, Serbian, Spanish, Turkish, Vietnamesea | Arabic, Chinese, English, Farsi, Finnish, French, German, Japanese, Korean, Norwegian, Portuguese, Spanish, Swedish, Turkish |
Test-retest | 0.47 [0.23,0.66] at three months | 0.48–0.86 [80] depending on the sample and test-retest interval |
Cronbach’s alpha | 0.87 | |
Heritability | 0.41 [0.32,0.49] between ages nine and 12 years, 0.42 [0.33,0.50] at 13 to 14 years, 0.29 [0.20,0.38] at 15 to 16 years and 0.37 [0.21,0.51] between ages 17 and 28 years (AE models, anxiety-depression scores) | 0.18 [0.05,0.31] (AE model, mean age 31 years, range 16–71) [84] |
Association with DSM-IV diagnoses | Significant from age 15Â years with alcohol and Marijuana dependence; and from age 13Â years for MDD and social anxiety (anxiety-depression subscale). | Not evaluated in general population |
Price | Free | Around 2 USD per questionnaire [99] |