Sensitivity and Specificity of the Humpty Dumpty Fall Scale (HDFS)

Monday, 7 July 2008: 10:50 AM
Patricia R. Messmer, PhD, RN, BC, FAAN , Nurse Researcher, Children's Mercy Hospitals & Clinics, Kansas City, MO
Deborah HIll-Rodriguez, ARNP, MSN, CS-BC , Nursing Department, Miami Children's Hospital, Miami, FL

Learning Objective 1: To learn about instrument development in Pediatric Nursing

Learning Objective 2: To discuss the development and implementation of the Humpty Dumpty Falls Scale (HDFS) Instrument

The Humpty Dumpty Fall Scale (HDFS) is a promising tool for screening pediatric patients for likelihood, “fall risk” while hospitalized. In a case-control study, Hill-Rodriguez & Messmer (2008) reported 1.87 odds ratio (OR) when HDFS score is greater than or equal to 12 (95% CI 1.05, 3.54, p = .03). OR suggests that patients with elevated HDFS approach twice the risk of falling as those with lower scores. Most important of screening properties are the sensitivity, specificity, and positive and negative predictive power of instruments (Rothman et al 2008). Test sensitivity is .85 (129/151) while test specificity is .24 (37/153). Overall percentage of patients correctly classified as to fall risk was 54.6% or (129+37)/304. Falls among hospitalized children report low prevalence and incidence rates, often .2%. Pediatric falls, currently reported may be artifacts of poor tracking and inappropriate definition of events rather than reflect real incidence. The significant OR arises from the good identification of the at-risk status of Cases by patient HDFS scores, its good sensitivity. The cutpoint used for the analysis is 12 or above; subjects with HDFS scores equal to or above 12 were identified high risk; movement to cutpoint-15 implies a sharp reduction in sensitivity. A t-test between HDFS1 and gender produced a difference between gender of 1.50, with a female mean of 13.35 and male mean of 14.85, t = 4.8547, p < .0001. A test between HDFS2 and gender showed difference between gender of .50, with t = 1.6267, p = .1048. The correlations indicate removing gender and age has virtually no affect on scores. HDFS should be used prospectively with patients to determine if HDFS screening properties found in the case-control design appear in clinical application. Clinicians using HDFS can be evaluated qualitatively in a prospective assessment, invaluable appraising the feasibility of HDFS.