Test-retest reliability of the diagnosis of schizoaffective disorder in childhood and adolescence - A systematic review and meta-analysis.

Objectives: Reliability of schizoaffective disorder (SAD) diagnoses is low in adults but unclear in children and adolescents (CAD). We estimate the test-retest reliability of SAD and its key differential diagnoses (schizophrenia, bipolar disorder, and unipolar depression).

Methods: Systematic literature search of Medline, Embase, and PsycInfo for studies on test-retest reliability of SAD, in CAD. Cohen's kappa was extracted from studies. We performed meta-analysis for kappa, including subgroup and sensitivity analysis (PROSPERO protocol: CRD42013006713).

Results: Out of > 4000 records screened, seven studies were included. We estimated kappa values of 0.27 [95%-CI: 0.07 0.47] for SAD, 0.56 [0.29; 0.83] for schizophrenia, 0.64 [0.55; 0.74] for bipolar disorder, and 0.66 [0.52; 0.81] for unipolar depression. In 5/7 studies kappa of SAD was lower than that of schizophrenia; similar trends emerged for bipolar disorder (4/5) and unipolar depression (2/3). Estimates of positive agreement of SAD diagnoses supported these results.

Limitations: The number of studies and patients included is low.

Conclusions: The point-estimate of the test-retest reliability of schizoaffective disorder is only fair, and lower than that of its main differential diagnoses. All kappa values under study were lower in children and adolescents samples than those reported for adults. Clinically, schizoaffective disorder should be diagnosed in strict adherence to the operationalized criteria and ought to be re-evaluated regularly. Should larger studies confirm the insufficient reliability of schizoaffective disorder in children and adolescents, the clinical value of the diagnosis is highly doubtful.