NOTE: The items for the problem index are almost identical to those in the AUA Symptom Index (International Prostate Symptom Score), although the order is slightly different. The primary difference is that the SPI asks for how much of a problem the symptom has been, while the AUASI asks how often it happens.
Components related to the symptoms of BPH over the past month:
(1) symptom problem index: 7 questions, scored from 0 (normal) to 4 (poor)
(2) impact index: 4 questions, scored from 0 (normal) to 3 or 4 (poor)
symptom problem index =
= SUM(points for all 7 items)
BPH impact index =
= SUM(points for all 4 items)
Interpretation:
• minimum scores: 0
• maximum symptom problem index: 28
• maximum BPH impact index: 13
• The higher the indices the greater the problem and impact.
Performance (Table 1, page AS149):
• good internal consistency (Cronbach alpha 0.88 for SPI and 0.79 for BII)
• good test-retest reliability (0.89)
• correlate well with symptom scores
• discriminate between BPH and normal patients (0.87 for SPI and 0.85 for BII)
• responsive to changes with treatment
