Hess et al. 2008
USA
PEDro=9
RCT
N=47

Population: Mean age=53yrs; Gender: males=47; Level of injury: quadriplegia=23, paraplegia=24; Severity of injury: AIS A= 27, B=10, C=10
Treatment: SCI patients with neurogenic bladder were divided into two groups. Each group was randomly selected to receive either 6 months of cranberry extract tablet 500 mg BID, or placebo and then the alternate for the next 6 months. Bladder management methods: condom catheter (n = 35), IC (n=8), and indwelling catheter (n=4)
Outcome Measures: Incidence of UTI (>104 organisms, one+ new symptoms, + evidence of tissue invasion – hematuria or pyuria; urine pH.

• No significant difference was seen between the two groups in the incidence of bacteriuria; however UTI were fewer in the period of cranberry treatment (7 UTI/6 mo) vs placebo (21 UTI/6 mo) (p=0.01).
• 34% of patients in the placebo period experienced at least one UTI; while only 13% experienced at least one UTI in the cranberry tablet consumption period (p=0.03).
• Urine pH was not significantly different between the two periods.
• The 22 participants with a high GFR reported no incidence of UTIs during the cranberry period, while 9 had 11 UTIs during the placebo period.

Lee et al. 2007
Australia
PEDro=7
RCT
N=305

Population: SCI with Neurogenic bladder and stable management: Mean age = 43.5 yrs; Gender: males = 83%, females = 17%; Level of injury: tetraplegia = 55%; Severity of injury: complete = 49%.
Treatment: Double-blinded comparison of methenamine hippurate (MH, 2g) with cranberry (1600mg), MH (2g) with cranberry placebo, cranberry (1600mg) with MH placebo or MH placebo with cranberry placebo).
Outcome Measures: Time to symptomatic UTI (culture), adverse events collected for up to 6 months.

• The Kaplan-Meier curves for MH and Cranberry compared to placebo showed no evidence of a treatment effect.
• The unadjusted analysis confirms that there was no statistically significant effect of MH tablets (HR 0.94, 95% confidence interval 0.68-1.32) or cranberry tables (HR 0.93, 95% CI 0.66-1.29).
• The only significant predictor of a future UTI was found to be the number of UTIs in the preceding 6 months.
• Common adverse effects included diarrhea or constipation.
• There was no difference in adverse event rates between the groups.

Linsemeyer et al. 2004 USA
PEDro=6
RCT
Initial N=37; Final N=21

Population: SCI with neurogenic bladder: Gender: males = 16, females = 5; Level of injury: C4-L1; Number of UTIs = 0 to 2.
Treatment: Randomized, crossover: placebo or cranberry tablets (400 mg) 3 times daily for 4 weeks. 
Outcome Measures: Urinary bacterial counts, white blood cell counts (WBC), combination of both counts.

• No statistically significant findings for the effect of cranberry tablets vs placebo:
  • Urinary bacterial count (p=0.96),
  • WBC count (p<0.27)or
  • Urinary bacterial + WBC count combination (p<0.27).

Waites et al. 2004
USA
PEDro=5
RCT
Initial N=74; Final N=48

Population: SCI with neurogenic bladder: Age = 20-73 yrs; Gender: males = 42, females = 6; Severity of injury: complete = 40, incomplete = 6; Time since injury = 1-30 yrs.
Treatment: Randomized to cranberry vs placebo capsules.
Outcome Measures:  Bacterial counts and urinalysis.

• No significant differences between groups:
  • Bacterial colony counts, bladder management method, or within groups over time (p=0.758).
  • Urinary leukocyte counts /ml urine, bladder management method, or within groups over time (p=0.929).
  • pH of urine, or within groups over time (p=0.659).
  • For each outcome, no interaction between groups, bladder management method, and time (p>0.05).
• pH higher for external collection vs intermittent catheter (p=0.046) for all time periods for both groups combined.

Reid et al. 2001
Canada
Downs & Black score=16
Prospective controlled trial
N=15

Population: SCI: Age = 21-78 yrs; Gender: males = 10, females = 4; Level of injury: paraplegia, teraplegia.
Treatment: 250 ml water and cranberry juice with meals successively, each for 7days treatment arms separated by 2 days.
Outcome Measures: Biofilm load, bacterial adhesion collected at day 0, 7 and 15.

• Cranberry juice vs water significantly reduces:
• Biofilm load (p=0.028); and compared to baseline (p=0.013,).
• Bacterial Adhesion counts (p<0.033).
• Gram positive counts (p=0.022).
• Gram negative counts (p=0.054).