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Posts Tagged effect size

## Statistics Done Wrong, And How To Do Better

Statistics is hard, often counterintuitive, and burdened with esoteric mathematical equations. Statistics classes can be boring and demanding; students might be tempted to call it “Sadistics.” Good statistics are essential to good research; unfortunately many scientists and even some statisticians are doing statistics wrong. Statistician Alex Reinhart has written a helpful book, Statistics Done Wrong: The Woefully Complete Guide, that every researcher and everyone who reads research would benefit from reading. The book contains a few graphs but is blissfully equation-free. It doesn’t teach how to calculate anything; it explains blunders in recent research and how to avoid them.

## Inadequate education and self-deception

Most of us have little or no formal education in statistics and have picked up some knowledge in a haphazard fashion as we went along. Reinhart offers some discouraging facts. He says a doctor who takes one introductory statistics course would only be able to understand about a fifth of the articles in The New England Journal of Medicine. On a test of statistical methods commonly used in medicine, medical residents averaged less than 50% correct, medical school faculty averaged less than 75% correct, and even the experts who designed the study goofed: one question offered only a choice of four incorrect definitions.

There are plenty of examples of people deliberately lying with statistics, but that’s not what this book is about. It is about researchers who have fooled themselves by making errors they didn’t realize they were making. He cites Hanlon’s razor: “never attribute to malice that which is adequately explained by incompetence.” He says even conclusions based on properly done statistics can’t always be trusted, because it is trivially easy to “torture the data until it confesses.” (more…)

## Antidepressants and Effect Size

Antidepressant drugs have been getting a bad rap in the media. I’ll just give 3 examples:

• On the Today show, prominent medical expert 🙂 Tom Cruise told us Brooke Shields shouldn’t have taken these drugs for her postpartum depression.
• In Natural News, “Health Ranger” Mike Adams accused pharmaceutical companies and the FDA of covering up negative information about antidepressants, saying it would be considered criminal activity in any other industry.
• And an article in Newsweek said  “Studies suggest that the popular drugs are no more effective than a placebo. In fact, they may be worse.”

Yet psychiatrists are convinced that antidepressants work and are still routinely prescribing them for their patients. Is it all a Big Pharma plot? Who ya gonna believe? Inquiring minds want to know:

• Are antidepressants more effective than placebo?
• Has the efficacy of antidepressants been exaggerated?
• Is psychotherapy a better treatment choice?

The science-based answers to the first two questions are clearly “Yes.” The best answer to the third question is “It depends.” (more…)