No higher risk of cancer after 9 years of testosterone replacement therapy

This is a reassuring study for those receiving testosterone replacement therapy. The question remains, how often should the PSA be checked in men receiving testosterone replacement? No higher risk of cancer after 9 years of testosterone replacement therapy : Family Practice News

How the irregular verb is being 'drived' to extinction

This is an interesting article that discusses my recent use of the word "drived"  when talking with my very smart teenage daughter. She's now able to correct my grammar, or if this article is correct, I'm still on the cutting edge.

How the irregular verb is being 'drived' to extinction

Frailty in elderly people.

This study in the Lancet discusses frailty, in which small stress to a frail person's homeostasis from for example an infection can result in major health issues and even death due to a decreased ability to respond in spite of maximal medical therapy. 

Modest salt reduction has important effects

This Cochrane review found significant and important blood pressure reduction when dietary sodium salt intake was reduced. The decrease in blood pressure was significant irrespective of sex and ethnic group. The authors recommend reduction of salt intake from 9-12 to 3 g/day.

Chelation Therapy Not Effective in Heart Disease

A recent study in JAMA concluded that chelation therapy may have a small effect on reducing adverse events in patients with a previous myocardial infarction. 

What they found is that in the chelation group, 222 out of 839 total patients suffered an adverse outcome. This compared to 261 out of 869 patients in the placebo group who suffered an adverse outcome. Let's take a look at their statistical analysis and you can decide if their conclusion is valid, or if you believe as I do that their raw numbers indicate no statistically significant difference between chelation and placebo.

1. CONFIDENCE INTERVALS: using confidence intervals, the difference in proportions between the two groups is insignificant when using 95% confidence intervals. The difference is 0.01 to -0.08. (see p147-148, Basic and Clinical Biostatistics by Dawson, 1994 for methodology)

2. USING THE Z-APPROXIMATION:  using this method to evaluate the difference in two proportions, we find that z= -1.64 which is not significant at the 0.05 level (see p148-149, Basic and Clinical Biostatistics by Dawson, 1994 for methodology)

3. CHI-SQUARE TEST:  using this methodology, we also find that the results are insignificant (see p125 - 128, Statistical Methods by Snedecor & Cochran 1989 for methodology).

So far, 3 out of 3 appropriate statistical tests to compare the difference between two proportions has concluded that there is NO BENEFIT from chelation therapy compared to placebo. There are several online calculators that will confirm the above, including medcalc.org

What the authors did in order to get a statistically significant result was to use a special type of hazard ratio, the Cox Proportional Hazards model. In this, the researchers don't simply look at the data at the end of the trial, but rather look at when each patient suffered the event during the trial. When you include when during the trial the patient had the adverse event, a statistically significant difference is found with a p-value of 0.035

The problem with using the Cox Proportional Hazards ratio exclusively, is that this statistical calculation estimates future events. It does not simply look at the raw data. If you look at the raw data, with no estimation or guessing about future events, then chelation has no benefit. However, if you decide to try to predict what would have happened if you had continued the trial for 5 years (instead of the 3 years they actually studied), only then is a statistically significant difference found.

Which is true? My sense of numbers is that you absolutely must analyze the raw data first, and give readers the statistical analysis of the raw numbers first. These raw numbers are actual observations, without trying to predict future events. Then, and only then, should researchers use future prediction models.

I am very skeptical about this trial and disappointed that such a prestigious journal such as JAMA would publish such research without insisting on an analysis of the raw data that did not rely on future prediction.

As the great Yogi Berra once said, "It's tough to make predictions, especially about the future." 

Statisticians need to listen to Yogi more.

Prostate Biopsies and Laboratory Error: Potential for Harm

A recent study found that there were pathology lab mix-ups in the analysis of prostate biopsy samples in approximately 1 out of 100 prostate biopsies. About 1% of the time, either one patient's biopsy was completely switched with another patient's biopsy; or one patient's biopsy was contaminated with another patient's biopsy material.

Rate of occult specimen provenance complica... [Am J Clin Pathol. 2013] - PubMed - NCBI

COMMENT: this is yet another consideration when deciding whether or not PSA testing is an appropriate screening tool for prostate cancer.

Family Care Network in Whatcom County identified as a leading primary-care provider in the country | Dean Kahn | The Bellingham Herald

Due the the work over many years of many doctors, including Marcy Hipskind, MD; Dave Lynch, MD; and Berdi Safford, MD the Family Care Network based in Bellingham, Washington has been recognized as one of the top primary care provider groups in the U.S. I joined FCN in 2005.

"Family Care Network has a long history of being innovative," said Larry Mauksch, who teaches in the Department of Family Medicine at the University of Washington and advises the network on ways to get better. "They're way ahead of the curve."

Family Care Network in Whatcom County identified as a leading primary-care provider in the country | Dean Kahn | The Bellingham Herald

Read more here: http://www.bellinghamherald.com/2013/02/04/2862069/family-care-network-in-whatcom.html#storylink=cpy