Psychometric properties of ambulatory and passive measures of negative symptoms: A systematic review

Abstract Background and Hypothesis Negative symptoms in schizophrenia spectrum disorders (SSD) are commonly assessed using clinician-rated instruments, which are vulnerable to bias and have limited ecological validity. Ambulatory and passive measures capturing real-world data may address these limitations but have unestablished psychometric properties. The latter are evaluated in this systematic review Study Design Databases were systematically searched using search terms relating to SSD, Negative Symptoms, and Measures. The ambulatory and passive measures’ psychometric properties, acceptability and feasibility regarding negative symptoms were evaluated and synthesised narratively due to methodological heterogeneity across eligible studies. Risk of bias was assessed using the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) checklist. Inclusion criteria were: (1) Written in English; (2) compared ambulatory measures against established negative symptom measures; (3) involved predominantly adult samples with SSD. Study Results Sixty-six articles representing 39 unique samples (total N = 2,678) were included. Evidence for construct validity was most consistent for Ecological Momentary Assessments of motivation/goal-directed behaviour and emotion regulation-related affective dynamics, and passive accelerometry and geolocation measures of travel. Moderate to high compliance indicated good feasibility. Construct validity was widely explored, reliability and internal consistency were rarely assessed, and other properties remain unexplored. Conclusion Ambulatory and passive measures show promise for assessing negative symptoms, particularly behavioural and motivational domains. However, methodological heterogeneity, limited psychometric evaluation, and inadequate reporting constrain interpretation. Future research should prioritise co-development with SSD populations, comprehensive psychometric testing, transparent reporting, and addressing privacy considerations. Other The protocol was registered on PROSPERO (CRD42020208475).