The semi-structured interview for bipolar at-risk states (SIBARS): psychometric properties and validation
Riccardo Stefanelli, Andrés Estradé, Matilda Azis, Alberto Stefana, Ilaria Bonoldi, Stefano Damiani, Andrea De Micheli, Valentina Floris, Umberto Provenzani, Luca Ballan, Sameer Jauhar, Silia Vitoratou, Daniel Ståhl, Marco Solmi, Christoph U. Correll, Andrea Pfennig, Allan H. Young, Paolo Fusar‐Poli
Abstract
Background Established psychometric instruments to detect individuals at high-risk of bipolar disorders (BD) are essential to advance preventive approaches. Methods The Semi-structured Interview for Bipolar At-Risk States (SIBARS)’s psychometric properties were evaluated through: (i) dimensionality (confirmatory factor analysis, CFA); (ii) reliability (internal/inter-rater reliability); and (iii) validity in terms of convergent validity (Hamilton Depression Rating Scale, HAM-D, Mini-International Neuropsychiatric Interview, MINI; Temperament Evaluation of Memphis, Pisa, and San Diego Autoquestionnaire, TEMPS-A; Young Mania Rating Scale, YMRS), divergent validity (Comprehensive Assessment of At-Risk Mental States, CAARMS; Hamilton Anxiety Rating Scale, HAM-A), concurrent criterion validity (Bipolar Prodrome Symptom Interview and Scale–Abbreviated Screen for Patients, BPSS-AS-P). Results A total of 193 participants were included. The CFA for depression plus mania showed excellent data fit (Root Mean Square Error Approximation = 0.02). Internal (Cronbach's α = 0.90; McDonald's ω = 0.96) and inter-rater (Intra-class Correlation Coefficient = 0.97) reliability were excellent. Convergent validity was confirmed by moderate-to-strong associations between the SIBARS mania scale and the YMRS ( β = 0.49, p < 0.001), the SIBARS depression scale and the HAM-D ( β = 0.54, p < 0.001), and the SIBARS cyclothymic temperament scale and the TEMPS-A ( β = 0.69 p < 0.001). Divergent validity was evidenced by very weak associations between SIBARS and CAARMS' outcomes ( χ 2 = 4.14, p = 0.042, phi = 0.15) or the HAM-A ( r = 0.16, p = 0.025). Concurrent validity was indexed by a significant association of SIBARS' researcher-based ratings and BPSS-AS-P participant-based ratings ( r = 0.23, p = 0.001). Limitations. The cross-sectional design did not allow to test predictive validity. Conclusions There is convincing psychometric evidence supporting the SIBARS as a reliable and valid instrument for detecting individuals at clinical high-risk of BD.