Table 2.

Baseline Characteristics by Treatment Group^*

	Amitriptyline	Placebo
Number of Subjects Randomized†	135	136
# (%) Female	115 (85%)	111 (82%)
Mean ± s.d. Age	38.0 ± 13.8	39.9 ± 14.0
Race
# (%) White/Caucasian	96 (71%)	104 (77%)
# (%) Black/African-American	18 (13%)	15 (11%)
# (%) Multi-race, Asian, Other	21 (16%)	17 (13%)
# (%) Ever Diagnosed with IC/PBS	62 (46%)	75 (55%)
Mean ± s.d. Years Since Diagnosis (if applicable)	1.4 ± 4.0	1.2 ± 3.0
Mean ± s.d. Years Since Onset of Initial Symptoms	6.3 ± 9.0	6.5 ± 9.9
Mean ± s.d. Pain Score (0–10)	5.8 ± 1.5	6.0 ± 1.8
Mean ± s.d. Urgency Score (0–10)	6.4 ± 1.8	6.4 ± 1.8
Mean ± s.d. Frequency Score (0–10)	6.8 ± 1.7	6.8 ± 1.8
Mean ± s.d. 24 -hour Voiding Frequency	13.9 ± 5.2	13.7 ± 5.7
Mean ± s.d. Nighttime Voiding Frequency	2.4 ± 1.8	3.0 ± 2.8
Mean ± s.d. IC Symptom Index	12.2 ± 3.1	12.0 ± 3.6
Mean ± s.d. IC Problem Index	11.1 ± 2.8	11.2 ± 3.0
Mean ± s.d. Wisconsin Symptom Survey	25.9 ± 8.6	26.7 ± 8.3

^*For the symptom scores shown, the measurements at the two baseline visits were averaged to give the overall baseline score.

^†Approximately nine subjects on each arm were missing data on voiding frequency, and eight subjects on each arm were missing data on years since symptoms began. At most one subject was missing data for all other measures.