LAY ABSTRACTHospital-acquired deconditioning can occur insidiously and rapidly as a result of enforced bed rest, immobilization or sedentary behaviours. While hospital-acquired deconditioning can occur in people of any age, it is particularly problematic in elderly people, as it can lead to irreversible functional decline. Hospital-acquired deconditioning is preventable with proactive, comprehensive regular assessment to detect changes in the performance of body systems. The time-period of assessment must be short, so that repeated assessments can be made during an acute hospital admission. At present there is no comprehensive, time-sensitive assessment instrument for hospital-acquired deconditioning. Based on a systematic scan of the literature, this paper proposes a core set of items that could be developed into a comprehensive, standardized assessment instrument for regular application by any healthcare provider during an acute inpatient stay, to identify incipient hospital-acquired deconditioning. The assessment items measured anthropometrics, gait, balance, mobility, activities of daily living, and skin integrity.Objectives: To systematically identify literature reporting on assessment instruments relevant for incipient hospital-acquired deconditioning during acute hospital admissions; evaluate their psychometric properties; and identify individual assessment items to form the basis of a comprehensive acute hospital test battery for hospital-acquired deconditioning. Design and data sources: Systematic evidence scan of MEDLINE, CINAHL, PubMed and Google Scholar from database inception to January 2018. Study selection: Papers reporting psychometric properties of assessment instruments to detect change in body function and structure, relevant to hospitalacquired deconditioning were selected. Included instruments should assess one or more elements of hospital-acquired deconditioning, reflect the short time-frame constraints of acute hospital admissions, and be able to be applied by any healthcare provider. Quality evaluation: Evidence of psychometric properties and utility were assessed using a validated instrument. Data extraction: Hospital-acquired deconditioning assessment items. Results: Eight potentially-relevant instruments were identified, with moderate-to-good validity and utility, but limited evidence of reliability. These instruments reported a total of 53 hospital-acquired deconditioning assessment items. Seventeen items with measurement periods greater than 3 days were excluded. The remaining items measured anthropometrics, gait, balance, mobility, activities of daily living, and skin integrity. Conclusion: These assessment items provide the basis of a multifaceted evidence-based test battery to comprehensively and repeatedly assess acute hospital inpatient function for incipient hospital-acquired deconditioning.