Posts Tagged ‘ Health ’

More on the AA paper

April 21, 2015
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More on the AA paper

This is a supplement to the previous post about a new research paper on the effect of Alcoholics Anonymous, and an NY Times exposition that I commented on. A misreading of that article led me to complain about per-protocol analysis, which wasn't the methodology behind the Humphrey et. al. research. I will explain their methodology in this post (known as instrumental variables analysis). *** In the last post, I showed…

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NYT likes new AA study. Why I am not convinced.

April 20, 2015
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NYT likes new AA study. Why I am not convinced.

[After communicating with Frakt, Humphrey and Dean Eckles, I realize that I was confused about Frakt's description of the Humphrey paper, which does not perform PP analysis. So when reading this post, consider it a discussion of ITT versus PP analysis. I will post about Humphrey's methodology separately.] The New York Times plugged a study of the effectiveness of Alcoholics Anonymous (AA) (link). The author (Austin Frakt) used this occasion…

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Yet another popular nutrition headline doesn’t stand up to scrutiny

April 1, 2015
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Yet another popular nutrition headline doesn’t stand up to scrutiny

Are science journalists required to take one good statistics course? That is the question in my head when I read this Science Times article, titled "One Cup of Coffee Could Offset Three Drinks a Day" (link). We are used to seeing rather tenuous conclusions such as "Four Cups of Coffee Reduces Your Risk of X". This headline takes it up another notch. A result is claimed about the substitution effect…

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Some data science principles from Gelman, Rosling and me

March 6, 2015
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Some data science principles from Gelman, Rosling and me

I discovered Hans Rosling's Gapminder work when I first started Junk Charts almost ten year ago, with this series of posts. So I was very excited to meet Hans yesterday at the Data, Children and Post-2015 Agenda Event hosted by the UNICEF Data and Analytics Section. And he gave a marvellous talk. I came away touched in equal parts by his humanity, the animated passion for his subject, and the…

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Composite ranking and numbersense

February 25, 2015
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Composite ranking and numbersense

Chapter 1 of Numbersense (link)uses the example of U.S. News ranking of law schools to explore the national pastime of ranking almost anything. Since there is no objective standard for the "correct" ranking, it is pointless to complain about "arbitrary" weighting and so on. Every replacement has its own assumptions. A more productive path forward is to understand how the composite ranking is created, and shine a light on the…

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Financial and statistical incentives to over-diagnose and over-treat

November 10, 2014
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Nice article in the New York Times about the "overdiagnosis" problem in cancer screening. The particular case is thyroid cancer in South Korea. There are a number of things about any form of screening tests that one should always bear in mind: Death rate is measured as the number of deaths divided by the number of people with the disease. The latter number increases with better diagnosis techniques. Better diagnosis…

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Pondering OCCAM data in medicine

October 9, 2014
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Pondering OCCAM data in medicine

The New York Times Magazine has a pretty good piece about the use of OCCAM data to solve medical questions, like diagnosis and drug selection. I'm happy that it paints a balanced picture of both the promise and the pitfalls. Here are some thoughts in my head as I read this piece: Small samples coupled with small effects pose a design problem in traditional clinical trials. The subjects of the…

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Background on my new 538 article on restaurant health grades

September 3, 2014
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Background on my new 538 article on restaurant health grades

Some behind-the-scenes comments on my recent article on New York's restaurant inspection grades; it appeared on FiveThirtyEight this Tuesday. *** The Nature of Ratings This article is about the ratings of things. I devoted a considerable amount of pages to this topic in Numbersense (link) - Chapter 1 is all about the US News ranking of schools. A few key points are: All rating schemes are completely subjective. There is…

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How to read Big Data studies

June 25, 2014
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This is part 3 of my response to Gelman's post about the DST/heart attacks study. The previous parts are here and here. One of the keys of vetting any Big Data/OCCAM study is taking note of the decisions made by the researchers in conducting the analysis. Most of these decisions involve subjective adjustments or unverifiable assumptions. Not that either of those things are inherently bad - indeed, any analysis one…

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Binge Reading Gelman

June 23, 2014
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Binge Reading Gelman

As others binge watch Netflix TV, I binge read Gelman posts, while riding a train with no wifi and a dying laptop battery. (This entry was written two weeks ago.) Andrew Gelman is statistics’ most prolific blogger. Gelman-binging has become a necessity since I have not managed to keep up with his accelerated posting schedule. Earlier this year, he began publishing previews of future posts, one week in advance, and…

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