Models to predict relapse in psychosis: A systematic review

<div><p>Background</p><p>There is little evidence on the accuracy of psychosis relapse prediction models. Our objective was to undertake a systematic review of relapse prediction models in psychosis.</p><p>Method</p><p>We conducted a literature search including studies that developed and/or validated psychosis relapse prediction models, with or without external model validation. Models had to target people with psychosis and predict relapse. The key databases searched were; Embase, Medline, Medline In-Process Citations & Daily Update, PsychINFO, BIOSIS Citation Index, CINAHL, and Science Citation Index, from inception to September 2016. Prediction modelling studies were assessed for risk of bias and applicability using the PROBAST tool.</p><p>Results</p><p>There were two eligible studies, which included 33,088 participants. One developed a model using prodromal symptoms and illness-related variables, which explained 14% of relapse variance but was at high risk of bias. The second developed a model using administrative data which was moderately discriminative (C = 0.631) and associated with relapse (OR 1.11 95% CI 1.10, 1.12) and achieved moderately discriminative capacity when validated (C = 0.630). The risk of bias was low.</p><p>Conclusions</p><p>Due to a lack of high quality evidence it is not possible to make any specific recommendations about the predictors that should be included in a prognostic model for relapse. For instance, it is unclear whether prodromal symptoms are useful for predicting relapse. The use of routine data to develop prediction models may be a more promising approach, although we could not empirically compare the two included studies.</p></div

Quality assessment of studies included in the systematic review–areas of concern using PROBAST guidelines.

<p>Quality assessment of studies included in the systematic review–areas of concern using PROBAST guidelines.</p

Type of study and findings.

<p>Type of study and findings.</p

Cation Disorder in Ferroelectric Ba₄M₂Nb₁₀O₃₀ (M = Na, K, and Rb) Tetragonal Tungsten Bronzes

The crystal structure of tetragonal tungsten bronzes, with the general formula A12A24C4B12B28O30, is flexible both from a chemical and structural viewpoint, resulting in a multitude of compositions. The A1 and A2 lattice sites, with different coordination environments, are usually regarded to be occupied by two different cations such as in Ba4Na2Nb10O30 with Na+ and Ba2+ occupying the A1 and A2 sites, respectively. Here, we report on a systematic study of the lattice site occupancy on the A1 and A2 sites in the series Ba4M2Nb10O30 (M = Na, K, and Rb). The three compounds were synthesized by a two-step solid-state method. The site occupancy on the A1 and A2 sites were investigated by a combination of Rietveld refinement of X-ray diffraction patterns and scanning transmission electron microscopy with simultaneous energy-dispersive spectroscopy. The two methods demonstrated consistent site occupancy of the cations on the A1 and A2 sites, rationalized by the variation in the size of the alkali cations. The cation order–disorder phenomenology in the tungsten bronzes reported is discussed using a thermodynamic model of O’Neill and Navrotsky, originally developed for cation interchange in spinels

PRISMA Flowchart of search and review strategy.

<p>PRISMA Flowchart of search and review strategy.</p