Introduction: The ACMEplus project aims to devise a standardised system for measuring case-mix and outcome in older patients admitted to hospitals in different parts of Europe for primarily 'medical' (i.e. not surgical or psychiatric) reasons. As a first step in this project, a systematic review was carried out to identify factors which had a significant influence on outcome in such patients.
Methods: The systematic search used Medline 1966-2000, Cinahl 1982-2000, Web of Science 1981-2000, reference lists of relevant papers and a hand search of Age and Ageing 1974-2000. A six-category grading system was devised to classify the 313 identified papers with regard to their relevance to the ACMEplus project, study design and power. The analysis of the 14 'category 1' papers is presented.
Results: The main areas of assessment of case-mix were function, cognition, depression, illness severity, nutrition, social elements, aspects of diagnosis and demographic details. Statistically significant predictors, for the four outcome measures, listed below were: For length of stay: functional status score, illness severity, cognitive score, poor nutrition, comorbidity score, diagnosis or presenting illness, polypharmacy, age and gender. For mortality: functional status score, illness severity, cognitive score, comorbidity score, diagnosis or presenting illness, polypharmacy, age and gender. For discharge destination: functional status score, cognitive score, diagnosis or presenting illness and age. For readmission rate: functional status score, illness severity, co-morbidity, polypharmacy, diagnosis or presenting illness and age.
Conclusions: Factors affecting outcome in older medical patients are complex. When looking at outcomes of hospital admission in older people it is important not just to look at routinely available statistics such as age, gender and diagnosis but also to take into account multifaceted aspects such as functional status and cognitive function.