The inpatient exposome in neurorehabilitation wards: a systematic review of indoor environmental exposures and patient-centered outcomes

Background Inpatient neurorehabilitation is delivered in wards where indoor environmental exposures may influence sleep, arousal, mobility, wayfinding and engagement outside therapy sessions. Objective To synthesize evidence on modifiable ward- or facility-level indoor exposures (the inpatient exposome) and patient-centered outcomes in neurological inpatients, with domain-specific validity appraisal. Methods We searched PubMed, Web of Science, Cochrane Library, Embase, EBSCOhost and Scopus from inception to 28 Oct 2025. Eligible studies quantified measurable, modifiable indoor exposures independent of therapy content and reported patient-level outcomes. Two reviewers screened studies and extracted data. Risk of bias was assessed with RoB 2, ROBINS-I and ROBINS-E; certainty per exposure-outcome pairing was assessed using a GRADE-informed approach. Results Thirty studies addressed light/circadian lighting, sound/noise, spatial layout and legibility, enrichment/communal communication spaces, nocturnal ward ecology, and thermal/indoor air quality as an a priori gap domain. Circadian-supportive lighting and structured nocturnal noise/care approaches showed the clearest signals for sleep quality, fatigue or perceived energy. Architectural configuration, spatial legibility and functional walking space were associated with out-of-bed behaviour, lower prolonged sedentary time and higher light-intensity physical activity; no consistent association emerged with moderate-to-vigorous activity. Enriched and communicative environments increased meaningful physical, cognitive and social engagement. Downstream functional recovery, discharge readiness and long-term outcomes remained heterogeneous and uncertain. Overall certainty was moderate for a small number of proximal comparisons and low or very low for most pairings because of confounding, exposure misclassification and outcome heterogeneity. Conclusions Ward ecology is a modifiable co-determinant of sleep, activity and participation in inpatient neurorehabilitation, but current evidence should not be interpreted as strong causal proof for downstream functional benefit. Pragmatic multicenter studies with objective exposure measurement, fidelity metrics and standardized outcomes are needed to inform scalable ward interventions and design standards.