ArticleReview: Safety in Numbers: The Development of Leapfrog`s CompositePatient Safety Score for U.S. Hospital
Accordingto DeVellis (2003),Z-test is defined as a statistical test where the allocation of thetest statistic of the null hypothesis can be assessed by a normaldistribution (DeVellis, 2003).In this regard, the z-test for every significant level has a singlecritical value that makes it more convenient than the student’st-test because the latter has separate critical values for everysample size (DeVellis, 2003).The convenience of the z-test can be better illustrated with thereview of Austin et al. article discussed herein entitled, Safetyin Numbers: The Development of Leapfrog`s Composite Patient SafetyScore for U.S. Hospital.
Thisarticle aimed at “developing a composite patient safety score thatgives patients, healthcare purchasers, and healthcare providers astandardized method of evaluating the safety of patients in the broadacute care hospitals within U.S.” (Austin et al. 2013, p. 1). Thearticle concluded that leapfrog composite score reflects the bestevidence about hospital’s efforts and outcomes in patient safety(Austin et al. 201). The hospital’s z-score was obtained bysubtracting the mean measure of performance for all hospitals fromthe respective hospital’s measure of performance and dividing theresult with the standard deviation of all hospitals (Salkind, 2014).From this calculation, the hospitals whose performance was close tothe national mean earned a z-score tending towards zero and thosethat performed better (that is, scores above the national mean)earned positive z-scores whereas those with measures below thenational mean earned a negative z-score (Salkind, 2014).
Itis evident that the z-score reveals very critical information aboutthe sample data and the conclusions drawn therefrom. The z-scoreallows the comparison and combination of individual scores fromdifferent sets of data making it simple to understand and explain. Inaddition to this, z-score method also produces results comparable toalternative rescaling approaches, hence it is extensively utilizedwithin the health field in such areas as in the Multiple SclerosisFunctional Composite (Corrigan, Kohn & Donaldson, 2000). In thisview therefore, the results of this research based on the z-scoreshowed that healthcare facilities in the US need to further improvetheir resource and capacities further when it comes to patient safety(DeVellis, 2003).
Austin,et al. (2013). ‘Safety in Numbers: The Development of Leapfrog`sComposite Patient Safety Score for U.S. Hospitals’. Journal ofPatient Safety. 9: 1-9. Retrieved 31 August, 2014 fromhttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact =8&ved=0CD4QFjAD&url=http%3A%2F%2Fwww.hospitalsafetyscore.org%2Fmedia% 2Ffile%2FJournalofPatientSafety_HospitalSafetyScore.pdf&ei=29wCVLLxFMGn0QXQ kID4BA&usg=AFQjCNEzeC9g7ezbMJFZu3i7B6FmTyERRA&sig2=KmzN- TPZQuRRQIChu8xTxA&bvm=bv.74115972,d.d2k.
Corrigan,J.M., Kohn, L.T. & Donaldson, M.S. (2000). Toerr is human: building a safer health system.Washington: National Academies Press.
DeVellis,R.F. (2003). Scaledevelopment: Theory and applications(2nd ed.). Thousand Oaks, Calif.: Sage Publications, Inc.
Salkind,Neil J. (2014). Statisticsfor People Who (Think They) Hate Statistics (5thed.).
Universityof Kansas:Sage Publications, Inc.