Measuring change in psychiatric symptoms using the Neuropsychiatric Inventory: Nursing Home version.
BACKGROUND
The Neuropsychiatric Inventory-Nursing Home version (NPI-NH) is a modified version of the Neuropsychiatric Inventory (NPI). Accurate interpretation of change in the symptom ratings on the NPI-NH, as with any measure, is a concern for both clinicians and researchers. The purpose of this article is to present data for the interpretation of reliable change in the NPI-NH scores for acute geriatric neuropsychiatry patients.


METHODS
Fifty-two geriatric psychiatry inpatients were administered the NPI-NH twice, at a 72-hour interval. Standard errors of difference scores were used to calculate confidence intervals for each of the NPI-NH subscales and the total score.


RESULTS
Based on the calculations described above, estimates of reliable change on the individual subscales ranged from plus or minus 1.29 points on the Euphoria/Elation subscale to 5.13 points on the Anxiety subscale. Statistically meaningful change on the Agitation and the Apathy subscales was established at 4.0 and 4.3 points, respectively. A change in the total score of plus or minus 22 points is required to exceed the possible range of measurement error, at a 0.80 confidence interval (CI).


CONCLUSIONS
Overall, the results of this study indicate that the clinician evaluating elderly psychiatric inpatients should interpret a change in the total score of less than 22 points with caution, because it may be due to measurement error.
Iverson
Grant L
GL
University of British Columbia, Vancouver, Canada. giverson@interchange.ubc.ca
Hopp
Grace A
GA
DeWolfe
Kimberley
K
Solomons
Kevin
K
D000368:Aged; D000369:Aged, 80 and over; D001955:British Columbia; D003072:Cognition Disorders / Q000175:diagnosis; D016001:Confidence Intervals; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis*; D008875:Middle Aged; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric