Table 2.

Incidence of episodes of symptomatic, antibiotic treated, urinary tract infection during 12 month preventive treatment period

Study population	No of participants included in analysis	Incidence rate (95% CI)	Absolute difference (90% CI)*	Incidence rate ratio (95% CI)†
Modified intention to treat‡
Antibiotic prophylaxis	102	0.89 (0.65 to 1.12)	—	—
Methenamine hippurate	103	1.38 (1.05 to 1.72)	0.49 (0.15 to 0.84)§	1.52 (1.16 to 1.98)
Strict intention to treat¶
Antibiotic prophylaxis	120	0.88 (0.65 to 1.11)	—	—
Methenamine hippurate	120	1.40 (1.08 to 1.73)	0.53 (0.20 to 0.86)	1.58 (1.24 to 2.03)
Per protocol**
Antibiotic prophylaxis	84	0.87 (0.61 to 1.13)	—	—
Methenamine hippurate	86	1.29 (0.93 to 1.66)	0.42 (0.05 to 0.79)	1.44 (1.02 to 2.02)
Post hoc, strict per protocol††
Antibiotic prophylaxis	82	0.83 (0.58 to 1.08)	—	—
Methenamine hippurate	71	1.13 (0.76 to 1.50)	0.30 (−0.08 to 0.67)	1.35 (1.06 to 1.71)

^*Unadjusted absolute difference in incidence rate.

^†Negative binomial model adjusted for menopausal status (pre-menopausal and peri-menopausal/post-menopausal), prior frequency of urinary tract infection (<4 and ≥4), and site (random effect).

^‡Modified intention to treat=primary analysis, including all patients with at least six months of follow-up data analysed according to their original treatment allocation.

^§Primary outcome.

^¶Strict intention to treat=including all patients who were randomised analysed according to their original treatment allocation.

^**Per protocol=including all patients with at least six months of follow-up data who achieved ≥90% adherence with any trial preventive treatment analysed according to their original treatment allocation.

^††Post hoc, strict per protocol=including only those patients who achieved ≥90% adherence with their original allocated treatment, excluding those who changed treatment arm during the trial.