Just read the Cochrane study, Dave. It's right there in black and white.
Just like any other research paper, there are assumptions about what to include and what not to. This isn't "exact" science.

You have to see the updated study. It says "Cranberry products (such as tablets or capsules) were also ineffective (although had the same effect as taking antibiotics), possibly due to lack of potency of the 'active ingredient'.
You obviously didn't reference the update. Cranberry "had the same effect as taking antibiotics".
Are we clear now?

Bar-Shavit Z, Goldman R, Ofek I, Sharon N, Mirelman D. Mannose-binding activity of Escherichia coli: a determinant of attachment and ingestion of the bacteria by macrophages. Infect Immun. 1980;29:417-424.

Bouckaert J et. al. Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol Microbiol 2005 Jan; 55(2):441-55.

Ofek I, Beachey EH. Mannose binding and epithelial cell adherence of Escherichia coli. Infect Immun. 1978;22:247-254.

Ofek I, Goldhar J, Eshdat Y, Sharon N. The importance of mannose specific adhesins (lectins) infections caused by Escherichia coli. Scand J Infect Dis Suppl. 1982;33:61-67.

Everyday reports from patients are positive, so common sense and a plausible mechanism of action supports the reports that it works. Patients aren't interested in someone pontificating about whether or not it's been tested in a formal clinical trial. They go to the health food store, buy some, and have complete respite within 48 hrs.
You are likely not a primary health care provider and certainly not one who works with natural remedies. The fact that it HAS worked in many clinical studies to date isn't sufficient reason to dismiss it based on one analysis. Real world patients use products that have worked for others based on personal testimonials. They don't buy through "argument".
I know people who experienced recurring UTIs. They took antibiotics and were back at the doctor's office a month later with the same problem. D-mannose finally got rid of the problem.
So why don't you conduct a properly designed clinical trial and put it to the test yourself?

I doubt that someone who is experiencing the pain and suffering of a UTI is a candidate for "cognitive bias" when the symptoms subside! What is your experience of those with a UTI infection who spontaneously experienced a remission without intervention? What is your experience of those who have returned with recurring infections? How many patients have you cured and with what? Why would you have a problem with patients being cured without antibiotics? What else have you got when they don't work. Please don't try to tell me that antibiotics are totally effective in all cases. I know better.
The problem most patients have is with conventional treatments that aren't working and no cogent feedback about why not. People aren't stupid. If they don't get satsifaction from the conventional route they'll try something else. All you'll end up doing is damaging your overall credibility by trying to browbeat them with notions that because there may be a lack of research that this means there is "no scientific evidence". Nobody with half a brain will interpret a lack of research as "no evidence". People who actively research medical treatments over time know that theories change pretty often. There is no final or last word on anything.
I think the cognitive bias is from a number of mainstream medical practitioners.
I have no interest in trying to "one-up" you.

1. If you weren't able to take a culture to determine what these women actually had, how can you scientifically conclude they had a UTI?
2. Simple UTIs at the time, how can you conclude these did not become recurrant?
3. How do you deal with bacterial resistance? Why didn't the patient finish the treatment?
4. Biofilms are the usual reason antibiotics didn't work. Next time try d-mannose.
5. Cranberry is a suggestion for prevention, not cure, which is where we're at in the discussion right now. Your patients already have it. Your take-home message is to thrown your hands up in the air when the antibiotics don't work. What does anybody have to be "careful of"? Maybe cranberry juice doesn't prevent UTI infection in everybody. Nothing is guaranteed to work 100% in everybody. You're left with the notion of prescribing antibiotics as a prevention for UTIs. That's nonsense. Once they kill off the good gut bacteria the patient will be more prone to UTIs. That's another reason why recurrent UTI's happen.

You are assuming that anyone who drinks cranberry juice will be likely inadvertently transferring E. coli where it shouldn't be...
Let's first ask the question, how does E. coli get into the urinary tract in the first place? It's actually pretty simple to avoid UTI infections with proper hygiene.
I suspect most people don't care for the taste of sour cranberry juice, which is why most people dropped out of various studies.

UTI's don't just materialize out of nowhere, Michael. I am not being condescending at all. Medical practitioners need to educate their patients nonetheless.

It's not the naturopathic way.

Naturopathy at least has elements of scientific feasibility, Mark. Not so homeopathy, for which Laurie is an enthusiatic proponent.

Dear Michael,

Definitely with you on the importance of the water ingredient, the more flushing the more comfortable one becomes ( a diluting effect) plus if swallowing cranberry juice besides being more interesting than plain water you are with the zeitgeist: it seems apparently absolutely everyone knows cranberry juice works, then you gain something of the placebo effect. I’ve fortunately only had one case of UTI, but it did not go after two courses of antibiotic with a couple of day’s abstinence in between before getting back to the doc. It was only when returning to a third doctor that I was able to get two consecutive courses of antibiotics to follow one immediately after the other that it went. I always believed that I had caught it from someone who had one. Yeah, I know, that hardly computes and most probably a wild coincidence, but never had one before or since. It made more sense than the explanation that suddenly I had become less scrupulous with my hygiene, of course accidents happen, but the anus is always close to the vagina.
Of course after you have had a bout, you certainly don’t want another, and so you keep on with the cranberry juice like it is some superstitious protection, but the sweetness of the commercial cranberry juice worried me and so I gave it away after a couple of weeks and touch wood it has not returned (10years). For me a prolonged course of antibiotics is the way to go, a simple course is wasting everyone’s time and an unnecessary wearing of the nerves in patient and doctor alike, more especially the patient.

Hi, Chris

Urinary tract infections are primary infections - they are not transmitted between people. They are more common in women because of the very anatomy that you describe. There would be very few women reaching older age without having had one.

The other group that are prone to UTIs are elderly men, in whom a growing prostate causes blockage, and retention of urine in the bladder - leading to increased risk for infection. The most common organism is Eschericia Coli - a bowel organism.

Thanks Sue,
But it still raises a few questions. How does Eschericia Coli from the bowel get into the male urinary tract? And why can’t that explanation apply to females?
And if in the male, UTIs are caused by urine retention, why is this then not the case in women especially when prolapse of the bladder is so common and is known to lead to urinary retention. Women with cystocele do complain of recurrent UTIs and the solution seems to be to conscientiously empty the bladder.

'But it still raises a few questions. How does Eschericia Coli from the bowel get into the male urinary tract? And why can’t that explanation apply to females?'

I think it may well be poor hygiene. I can't quote any studies ( just woke up from nightshift, and still in a blur), but hand hygiene is often poor, with hand washing rates as low as 30% after using the toilet. Sounds exist, but women do tend to have better hand hygiene than men, but, yes it is plausible that this is the cause f infection in women.

Bear in mind that in some public toilets the taps/basin appear as dirty as the urinal!

Ok, so let’s pretend I am a man, I have visited the toilet and have the Escheria Coli on my hands? How does it then get into my urinary tract?

Chris - the E Coli are in small numbers on the perineum (area between urethra and anus). If they enter the bladder and there is stagnant urine, they multiply.

Dear Sue, I most appreciate your replies, but wonder about the effects of pelvic organ prolapse on the Australian female population. With 30,000 hysterectomies a year, I don’t think the number of cystoceles would be small.
Have I got it right yet? If you have a UTI, it is probably due to the fact of incomplete urination which means the usual constant flushing of the always present E Coli does no longer prevent its multiplying in the urethra and the pooled non shifting urine in the bladder provides ideal conditions.
With the female anatomy, the process of the march of E Coli appears a short simple journey, but in the male anatomy, it does not seem simple at all. And in the case of old men with prostate enlargement would not a dribble do the job?
What protects babies in nappies?

Chris, the problem in women is the short distance from the outside into the bladder, due to a short urethra (as you described)."The infection occurs when the organisms move from the perineum, through the urethra and into the bladder. It is the flushing/emptying of the bladder that helps dilute the organisms - not flushing the urethra.

For men, UTIs are much less common UNTIL prostatic obstruction causes pooling/stagnation of urine in the bladder, which allows the organisms to multiply. UTIs in older men then become much more common.

UTIs are very common in elderly women, but not because of urinary retention - which is uncommon in women. This Australian paper from 2000 has some useful information: Voiding Difficulty in Women (at http://link.springer.com/article/10.1007%2FPL00004020?LI=true#page-1). The author states that the most common complication of cystocele is incontinence rather than obstruction. It is reported that "residual urine in women is uncommon. Only 5% of the normal female population and 13% of symptomatic women will have a residual of over 30mls.

For babies in nappies, the bladder gets completely emptied - there is no pooling of urine in the bladder - it is captured outside.