Age and Ageing Advance Access originally published online on October 1, 2008
Age and Ageing 2008 37(6):621-627; doi:10.1093/ageing/afn203
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Systematic Review |
A systematic review and meta-analysis of studies using the STRATIFY tool for prediction of falls in hospital patients: how well does it work?
1 School of Health and Social Care (& Institute of Health Sciences), University of Reading, London Road, Reading, RG1 5AQ, UK
2 Department of Medicine, McMaster University, Hamilton, Ontario, Canada
3 Department of Kinesiology, University of Waterloo, Canada
4 Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
5 Schulich School of Medicine and Dentistry, University of Western Ontario, Canada
6 Centre for Evaluation of Medicines, St Joseph's Healthcare, Hamilton, Ontario, Canada
Address correspondence to: Dr D. Oliver. Tel: (+44) 1183786851; Fax: (+44) 1183786862. Email: d.oliver{at}reading.ac.uk
Background: STRATIFY is a prediction tool developed for use in for hospital inpatients, using a 0–5 score to predict patientswho will fall. It has been widely used as part of hospital fall prevention plans, but it is not clear how good its operational utility is in a variety of settings.
Objectives: (i) to describe the predictive validity of STRATIFY for identifying hospital inpatients who will fall via systematic review and descriptive analysis, based on its use in several prospective cohort studies of hospital inpatients; (ii) to describe the predictive validity of STRATIFY among inpatients in geriatric rehabilitation via meta-analysis and (iii) in turn, to help practitioners and institutions wishing to implement interventions to prevent in-hospital falls.
Methods: a systematic literature review of prospective validation studies of STRATIFY for falls prediction in hospital inpatients. For inclusion, studies must report prospective validation cohorts, with sufficient data for calculation of sensitivity (SENS), specificity (SPEC), negative and positive predictive value (NPV and PPV), total predictive accuracy (TPA) and 95% confidence intervals (CI). We performed meta-analysis using precision-weighted fixed- and random-effects models using studies that evaluated STRATIFY among geriatric rehabilitation inpatients.
Measurements: key features of the patient population, setting, study design and numbers of falls/fallers were abstracted. SENS, SPEC, PPV, NPV, TPA and 95% CI were reported for each cohort. Pooled values and chi-squared test for homogeneity were reported for a meta-analysis of studies conducted in geriatric rehabilitation settings.
Results: forty-one papers were identified by the search, with eight ultimately eligible for inclusion in the systematic review and four for inclusion in the meta-analysis. The predictive validity of STRATIFY, using a random-effects model, for the four studies involving geriatric patients was as follows: SENS 67.2 (95% CI 60.8, 73.6), SPEC 51.2 (95% CI 43.0, 59.3), PPV 23.1 (95% CI 14.9, 31.2), NPV 86.5 (95% CI 78.4, 94.6). The Q(3) test for homogeneity was not significant for SENS at P = 0.36, but it was significant at P < 0.01 for SPEC, PPV and NPV. TPA across all four studies varied from 43.2 to 60.0.
Conclusion: the current study reveals a relatively high NPV and low PPV and TPA for the STRATIFY instrument, suggesting that it may not be optimal for identifying high-risk individuals for fall prevention. Further, the study demonstrates that population and setting affect STRATIFY performance.
Keywords: falls, hospital, predictive validity, STRATIFY, systematic review, elderly
Received 1 February 2008; accepted in revised form 3 July 2008.