Urinary Tract Infection

Topic

Cranberry products for preventing urinary tract infection in women

PICO

Population: Women

Intervention: Cranberry consumption

Compare: Cranberry consumption compare to no treatment, placebo, or prophylactic treatment for the prevention of urinary tract infection (UTI)

Outcome: Incident rate of UTI recurrence after consuming cranberry products

Quality Appraisal

Quality appraisal of literature listed was conducted in three articles, including one randomised controlled trial, one quantitative research, and one systematic review. The Critical Appraisal Skills Programme (CASP) was used to assess the quality of the selected papers. Both the randomised controlled trial and the quantitative research were assessed using CASP-

Most researches used cranberry juice or cranberry capsules / tablets as study intervention. There is also no standardisation of description of dosage. In 7 included RCT papers, 5 studies (Win et al., 2008; Barbosa-Cesnik et al., 2011; Beerepoot, 2012; Bianco et al., 2012; Takahashi et al., 2013) mentioned the amount of PAC (proanthocyanidins) used in their study, which is the compound that deemed to be the “active” ingredient in cranberries.

Cranberry juice

Of the four articles evaluated the effectiveness of cranberry juice, their comparison groups slightly varied (Barbosa-Cesnik et al.,2008; Wing et al., 2008; Stapleton et al., 2012; Takahashi et al., 2013). Although all four studies included placebo as their controlled group, 2 studies were 3 arms designs with different amount of cranberry juice plus different amount of placebo in each arm (Wing et al., 2008; Stapleton et al., 2012). Of these four studies, 240 mL (112 mg PAC) of cranberry juice was used daily in Barbosa-Cesnik’s study (2008); Takahashi et al. (2013) stated using 125 mL/d (40 mg PAC) cranberry juice; Wing et al. (2008) reported using 240 mL once or twice daily; and Stapleton et al. (2012) used 120-240

(2008) used cranberry juice as study intervention. Tolerability and compliance was a problem in this study. 60.3% participants who withdrew were because of the adverse effects, with gastrointestinal upset as the main issue. Multiple doses daily group had the lowest adherence. Due to the poor compliance and tolerability, the dosing regimen had to change from cranberry juice 3 times a day to twice daily. This study also had a high withdrawal rate of 38.8%. Stapleton et al. (2012) had similar problems. Although they used lower juice volume than other studies, participants who reported adverse effects in cranberry juice group was still twice as that of placebo group. Although this study’s adherence rate was relatively high with more than 90% in both study and control group, this outcome needs to be interpreted with caution. Adherence in this study was self-report rather than measurement because the latter option was not available during the trial.

Takahashi et al. (2013) also used cranberry juice as intervention. This study reported one adverse effect (burning like sensation) only. The reason for the differing rates of adverse effects might be able to be explained by the differences of cranberry juice. In the first two studies (Wing et al., 2008; Stapleton et al., 2012), cranberry juice was both provided by Ocean Spray Cranberries Inc., with 8 oz. (240ml) a bottle, while Takahashi et al. (2013) used cranberry juice provided by Kikkoman food products & The Nisshin Oillio