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A new scale for assessment of severity and outcome in i NPH
Author(s) -
Hellström P.,
Klinge P.,
Tans J.,
Wikkelsø C.
Publication year - 2012
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.2012.01677.x
Subject(s) - ordinal scale , modified rankin scale , cronbach's alpha , convergent validity , physical medicine and rehabilitation , scale (ratio) , physical therapy , medicine , psychology , psychometrics , statistics , psychiatry , clinical psychology , mathematics , ischemic stroke , ischemia , internal consistency , physics , quantum mechanics
Objective To present a new, continuous, calibrated and norm‐based scale for the grading of severity and assessment of treatment outcome in idiopathic normal pressure hydrocephalus (i NPH ). Patients and methods A scale designed for the assessment of the four domains, gait, neuropsychology, balance and continence, using ordinal ratings and continuous measures, was developed. Data from a series of 181 consecutive i NPH patients were used to calibrate the continuous parts of the scale and to describe the distributional properties of the ordinal ratings. Data from normative studies were used to determine the limits for normal scores. Results The construction of the scale made it well equipped to separate i NPH patients at baseline, and the total scores assumed a bell‐shaped, approximately normal distribution. All four domain scores correlated significantly with each other, underscoring the well‐known syndromatic nature of i NPH , and justifying the use of a total score to describe the patients. Reliability [ C ronbach's α for the total score = 0.74, and for the domains of gait and neuropsychology, 0.86 and 0.89, respectively) and validity estimates (convergent validity evaluated by Spearman rank correlations for the scale and the modified R ankin scale (ρ = −0.61) and the mini mental state examination (ρ = 0.57)] are satisfying. Conclusion The i NPH scale covers the four most important symptom domains and the full range of severity of the i NPH syndrome. The scale is sensitive, reliable, valid and feasible. We recommend that it should be used in future i NPH research.