You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: Survey on Fall Detection and Fall Prevention Using Wearable and External Sensors 
Chapter Title:  STRATIFY 
1. Abstract of Cited Paper (BIB001):  OBJECTIVES ::: To identify clinical characteristics of elderly inpatients that predict their chance of falling (phase 1) and to use these characteristics to derive a risk assessment tool and to evaluate its power in predicting falls (phases 2 and 3). ::: ::: ::: DESIGN ::: Phase 1: a prospective case-control study. Phases 2 and 3: prospective evaluations of the derived risk assessment tool in predicting falls in two cohorts. ::: ::: ::: SETTING ::: Elderly care units of St Thomas's Hospital (phase 1 and 2) and Kent and Canterbury Hospital (phase 3). ::: ::: ::: SUBJECTS ::: Elderly hospital inpatients (aged > or = 65 years): 116 cases and 116 controls in phase 1,217 patients in phase 2, and 331 in phase 3. ::: ::: ::: MAIN OUTCOME MEASURES ::: 21 separate clinical characteristics were assessed in phase 1, including the abbreviated mental test score, modified Barthel index, a transfer and mobility score obtained by combining the transfer and mobility sections of the Barthel index, and several nursing judgements. ::: ::: ::: RESULTS ::: In phase 1 five factors were independently associated with a higher risk of falls: fall as a presenting complaint (odds ratio 4.64 (95% confidence interval 2.59 to 8.33); a transfer and mobility score of 3 or 4 (2.10 (1.22 to 3.61)); and primary nurses' judgment that a patient was agitated (20.9 (9.62 to 45.62)), needed frequent toileting (2.48 (1.08 to 5.70)), and was visually impaired (3.56 (1.26 to 10.05)). A risk assessment score (range 0-5) was derived by scoring one point for each of these five factors. In phases 2 and 3 a risk assessment score > 2 was used to define high risk: the sensitivity and specificity of the score to predict falls during the following week was 93% and 88% respectively in phase 2 and 92% and 68% respectively in phase 3. ::: ::: ::: CONCLUSION ::: This simple risk assessment tool predicted with clinically useful sensitivity and specificity a high percentage of falls among elderly hospital inpatients.

Literature Review:
St Thomass' risk assessment tool in falling elderly inpatients (STRATIFY) is a risk assessment tool developed to predict elderly patient falls in hospitals BIB002 . It uses a 0-5 (low risk-high risk) score system to rank patients' likelihood of experiencing a fall. Patients of elderly units from St Thomas, Kent and Canterbury Hospital in the UK were monitored in order to identify the risk factors of a fall. After a fall occurs a series of falling characteristics (risk factors) are recorded in a log and used to compute the probability of a future fall. Five factors were found to have a direct impact in falls and were used to build the risk assessment tool. These factors were agitation, patient was admitted with a fall or patient fell inside the ward, visual impairment, need of toileting, and a transfer and mobility score (0-6) based on the transfer and mobility section of the barthel index BIB001 . The recall and specificity of the score for fall prediction were 92% and 68% respectively.