Responsiveness of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI).
OBJECTIVE
The NIH-Chronic Prostatitis Symptom Index (NIH-CPSI) was developed to assess symptoms and quality of life in men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). We assessed the responsiveness of the NIH-CPSI to change over time and defined thresholds for changes perceptible to patients.


METHODS
We studied 174 men with CP/CPPS who participated in a placebo-controlled randomized clinical trial. Changes from baseline to six weeks in the NIH-CPSI total score and pain, urinary, and quality of life subscores were compared to a global response assessment (GRA). Effect sizes and Guyatt statistics were calculated to evaluate responsiveness; 95% confidence intervals were produced using bootstrapping.


RESULTS
All scores decreased over time with the largest decrease in subjects who reported on the GRA that they were markedly improved. The NIH-CPSI total, pain, and quality of life scores were highly responsive in the improved groups; the urinary score showed minimal responsiveness. There was no evidence of responsiveness among those subjects who worsened on the trial. ROC curves identified a 6-point decline in the NIH-CPSI total score as the optimal threshold to predict treatment response.


CONCLUSIONS
The NIH-CPSI total score and pain and quality of life subscores are responsive to change over time.
Department of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021, USA. kpropert@cceb.upenn.edu
K J
KJ
Propert
M S
MS
Litwin
Y
Y
Wang
R B
RB
Alexander
E
E
Calhoun
J C
JC
Nickel
M P
MP
O'Leary
M
M
Pontari
M
M
McNaughton-Collins
D000328:Adult; D002908:Chronic Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009316:National Institutes of Health (U.S.); D010147:Pain Measurement; D011472:Prostatitis / Q000503:physiopathology*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014481:United States