*And by shit I mean non-shit sources
Yeah, I've double checked and I'm not seeing anywhere where he said that pubmed, the CDC or WHO are "shit sources." He says that cochrane.org is better but that they only accept gold standard material, so sometimes they lack data on some things.
Ok, I have no problem with that.
Incidentally, Sheb:
Topical silver for treating infected wounds
The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer
healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up,
I notice that the section you quoted ends with a comma. Let's look at the entire sentence you're quoting, shall we?
The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up, although a greater reduction of ulcer size was observed with the silver-containing foam.
In fact, let's look at the entire paragraph:
"The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up, although a greater reduction of ulcer size was observed with the silver-containing foam. The use of antibiotics was assessed in two trials, but no significant differences were found. Data on pain, patient satisfaction, length of hospital stay, and costs were limited and showed no differences. Leakage occurred significantly less frequently in patients with leg ulcers and chronic wounds treated with a silver dressing than with a standard foam dressing or best local practice in one trial."
Huh. Well, that's interesting. Faster healing and less leakage with the silver wound dressings. But now I'm curious. This is only an executive summary we're looking at. Let's check the
full text:
COMPARISON 1: Silver-containing foam dressings compared with hydrocellular foam
One trial (Jørgensen 2005) compared silver-containing foam (Contreet®) with hydrocellular foam (Allevyn®). Wound duration at the start of the trial was similar in both groups (medians 1.1 and 1.0 years, respectively), but ranged substantially (from 0.1 to 32 years). Baseline median wound sizes were also similar: 5.9 (range: 1.9-37.4) and 6.8 (range: 2.1-33.
cm2, respectively.
Primary outcome:
Wound healing
Four different measures of wound healing were used:
the number of ulcers healed completely (within the four-week trial period);
the mean and median ulcer area in cm2;
the mean and median relative reduction in ulcer area in %, calculated as the median of each patients' wound size reduction; and
the number of ulcers not responding to the treatment and increasing in size.
Assessments of healing were made after one, two, three and four weeks of treatment. There was no significant difference in rates of complete healing; five ulcers out of 65 patients (8%) treated with Contreet® and five out of 64 (8%) treated with Allevyn® healed completely during the trial period (RD: 0.00; 95% CI: -0.09 to 0.09) ( Analysis 1.4).
The median ulcer area after four weeks of treatment was not significantly smaller in the Contreet® group (3.0 cm2; range: 0.0-35.9) than the Allevyn® group (4.5 cm2; range: 0.0-33.6). The WMD was -0.30 cm2 (95% CI: -2.92 to 2.35) ( Analysis 1.5).
The median relative reduction in ulcer area after four weeks of treatment, was significantly (P=0.034) greater in the Contreet® group (54.8% of the original size, i.e. 45.2% reduction) than the Allevyn® group (74.6% of original size, i.e. 25.4% reduction). The WMD was -15.70 cm2 (95%CI: -29.5 to -1.90). ( Analysis 1.6).
Nine of 65 (14%) of the ulcers in the Contreet® group, and 16 of the 64 (25%) in the Allevyn® group did not respond to the treatment and increased in size (RD: -0.11; 95% CI: -0.25 to 0.02) ( Analysis 1.7).
In summary, although relative wound size reduction was significantly quicker in the Contreet group, there was no significant difference in rates of complete wound healing after four weeks.
Fascinating!Fascinating for multiple reasons, in fact. They're comparing
two difference foams. One containing silver, and one not containing silver. They are not comparing a silver test group to an empty control group. This mean that, even if there were no difference in the results, that would mean that the silver foam was
as good as the other wound dressing.
But in fact, they not only concluded that the the silver foam was as good as, they concluded that wound size reduction was, quote "significantly quicker" with the foam containing silver.
How about that!
But, they note that despite the fact that healing was much faster for the silver group, the ratio of people in each group who had "completely healed" at the end of four weeks was the same. And that's the part that you quoted from the summary. *shrug* ok. Nevertheless, the study concluded that the wounds treated with dressings containing silver healed faster and leaked less.
COMPARISON 2: Silver containing alginate compared with alginate
One trial (Meaume 2005) compared silver containing alginate (Silvercel®) with alginate alone (Algosteril®). At baseline the silver group differed from the comparison group. Significantly fewer patients in the silver group were aged 80 years or over (21% compared with 52% in the alginate group), significantly more patients had diabetes (33% versus 12%) and their wounds tended to be larger in size at baseline (39.1 cm2 versus 23.9 cm2 ) and of longer duration (32.6 versus 18.3 months). In the analysis the difference in wound size was compensated for by subtracting the baseline values. The remaining characteristics did not differ between the groups.
Primary outcome:
Wound healing
Four different measures of wound healing were used:
the number of ulcers healed completely (within the four-week trial period);
the absolute wound area decrease (within the four-week trial period);
relative wound area decrease (within the four-week trial period); and
healing rate measured as cm2 per day at 1, 2, 3, and 4 weeks, and for the total four-week trial period.
For the first three measurements no statistically significant differences were found.
At the end of the four-week trial period 1 ulcer healed in both groups; 1/51 versus 1/48 (risk difference 0.00; 95% confidence interval -0.06 to 0.05)( Analysis 2.1).
The mean absolute reduction in wound area in the silver containing alginate group was 8.9 (16.0)cm2 versus 4.4 (11.3) cm2 in the alginate group (weighted mean difference 4.50 cm2; 95% confidence interval -0.93 to 9.93)( Analysis 2.2) .
Within the four-week trial period the relative wound area decreased in the silver containing group by 23.7% and in the alginate group by 24.0% (weighted mean difference -0.30 cm2; 95% confidence interval -17.08 to 16.48)( Analysis 2.3).
The wound healing rate in cm2 per day at week 1; was -0.79 for the silver containing alginate group versus -0.37 in the alginate group, at week two -0.55 versus -0.23, at week three -0.14 versus -0.14, at week four -0.52 versus -0.16, and for the complete four-week trial period -0.32 versus -0.16 (Analysis 02:4-08). For the fourth measurement Meaume 2005 reported a statistically significant difference of P=0.024. We calculated the weighted mean difference of 0.16 cm2; 95% with a confidence interval of -0.03 to 0.35 ( Analysis 2. which indicates only a small treatment effect.
Also fascinating!The amount the wounds has reduced in size after four weeks was
double in the silver group. But, unfortunately, we need to dismiss this case, because the original sample groups were significantly different. Yes, the silver showed better results...but in this case it's not necessarily meaningful that it showed better results, because the silver wounds were larger and on younger people. Ok, we have to dismiss this one as insufficiently rigorous. That's reasonable.
COMPARISON 3: Silver-containing foam compared with best local practice
One trial (Münter 2006) compared Contreet® with best local practice, i.e. a range of dressings: foams & alginates (53%), hydrocolloids (12%), gauze (3%), silver dressings (17%), other antimicrobial dressings (9%) or other active dressings (6%).
Wound aetiologies were similarly distributed in both groups. Baseline wound sizes in the Contreet and local best practice groups were reported (medians: 20.0 cm2 and 12.0 cm2, and means: 52.9 cm2 and 36.6 cm2, respectively), although variation was high (from 0.1 to 700 cm2 and from 0.1 to 400 cm2, respectively). Exudate levels at baseline in the Contreet® and best practice groups were 'moderate' (three-level rating scale) and the condition of the peri-ulcer skin was normal in 24.3% and 24.0%, respectively. Quality of life scores were similar at baseline.
Primary outcome:
Wound healing
This was expressed as the median relative reduction in ulcer area in %.
The median relative reduction in ulcer area after four weeks of treatment was 50% in the Contreet® group, and 34% in the best local practice group, it should be noted that this result is against the direction of baseline bias. Analysis of the results at the final visit whilst carrying forward the last observation, showed a difference of 47% compared with 32% in favour of Contreet®, which was statistically significant (P=0.0019). In subgroups of venous leg ulcers and pressure ulcers the results as to ulcer area reduction were similar. Trialists did not report how many patients had final endpoint data and how many required that data from the last observation was carried forward.
In summary, relative wound size reduction was significantly quicker in the Contreet group. However, this outcome parameter was used as an unblinded, surrogate endpoint for wound healing.
Once again,
fascinating!After four weeks, the group with silver showed wound reduction of 50%, compared to the not-silver group which only showed 34% wound reduction. And as of final visit, wound reduction carrying previous results forward showed wound reduction with the silver group at 46% compared to 32% in the not-silver group.
Silver wins!
However, there was an..."unblinded surrogate endpoint." Huh. Ok, had to
look that up. Sounds to me like in plain English, they were specifically looking for results from silver and stopped the study when they got that result rather than continuing to evaluate over greater time.
...ok. That does sound like silver probably performed better, but I guess if we're going for our "gold standard" we have to dismiss this one too.
Final results: Three sets of data.
All three showed superior performance from silver, but two of them had to be disqualified because the studies were insufficiently rigorous. One of the three
was sufficiently rigorous, and it
did show positive results from silver. But one study is not enough data to come to a definite conclusion.
And here is the part out of all this that you quoted:
The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up,
I think it's completely reasonable that you didn't go digging through the entire study. No problem. But yeah...quoting only half of a sentence and leaving out the other half of the sentence that supports my position...that was poor form. I'll give you the benefit of a doubt that you were simply in a hurry.
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