false positives

Fake-positives on the ADHD diagnostic test

Anecdotal evidence that students are faking having ADHD so that they will get untimed tests like the SAT.

http://www.thedailybeast.com/articles/2012/01/25/faking-adhd-gets-you-into-harvard.html

http://www.myspecialneedsnetwork.com/forum/topics/faking-adhd?commentId=5940659%3AComment%3A3412

President Kirchner of Argentina - False positive cancer diagnosis

http://www.nytimes.com/2012/01/08/world/americas/cancer-diagnosis-for-argentine-president-was-wrong-spokesman-says.html?hp

January 7, 2012

Argentine Leader Is Told Thyroid Was Cancer-Free

By REUTERS

• BUENOS AIRES (Reuters) — President Cristina Fernández de Kirchner of Argentina never had thyroid cancer despite a diagnosis of the disease last month, her spokesman said on Saturday.
• The government announced just after Christmas that Ms. Kirchner had cancer, but the spokesman, Alfredo Scoccimarro, said an examination of her thyroid gland, which was removed Wednesday, had found no cancerous cells.
• “The original diagnosis has been modified,” he said at a news conference. “The presence of cancer cells was discarded.”
• Eduardo Faure, a thyroid cancer expert in Buenos Aires who is not on the president’s medical team, said a small number of such cases turned out to be “false positives.”
• “The cells may originally appear to be cancer, but in 2 percent of cases, after the operation, when a more thorough examination can be performed, it turns out they are not,” he said.

 

The cancer diagnosis became an international imbroglio when Hugo Chavez mused that perhaps the U.S. had figured out a way to induce cancer as several leftist south american leaders had recently been diagnosed with the disease

http://www.telegraph.co.uk/news/worldnews/southamerica/venezuela/8981643/Cristina-Kirchner-cancer-Hugo-Chavez-ponders-if-US-gave-Latin-American-leaders-cancer.html

Yearly mammograms generate significant # of false positives

http://www.msnbc.msn.com/id/44936934/ns/health-cancer#.TpzvLpsr2Go

"What we found was more than half of women participating in annual screening would have a false positive after 10 years," Rebecca Hubbard of the Group Health Center for Health Studies in Seattle, said in a telephone interview.

"The risks (of a false positive) are decreased by a third with biannual screening compared to annual after 10 years," Hubbard said.

Over the course of 10 years, screening every other year instead of yearly lowered a woman's risk of having a false positive to 42 percent from 61 percent.

And while the risk of a false positive from mammogram screening was about the same for women in their 40s or 50s, women who started screening for breast cancer in their 40s had a higher risk over their lifetime of having a false positive.

 

Tornado sirens not heeded due to false alarms

http://www.nytimes.com/2011/09/21/us/missouri-tornado-sirens-not-heeded.html?src=recg

http://www.weather.gov/os/assessments/pdfs/Joplin_tornado.pdf

From the National Oceanic and Atmospheric Administration report:

Many of the key findings within this report involved societal aspects of warning response and risk perception.  Responding to warnings is not a simple act of stimulus-response, rather it is a non-linear, multi-step, complex process.  Relationships between false alarms, public complacency, and warning credibility are highly complex as well.  

The vast majority of Joplin residents did not immediately take protective action upon receiving a first indication of risk (usually via the local siren system), regardless of the source of the warning.  Most chose to further assess their risk by waiting for, actively seeking, and filtering additional information.  

The reasons for doing so were quite varied, but largely depended on an individual‘s ―worldview formed mostly by previous experience with severe weather.  Most importantly, the perceivedfrequency of siren activation in Joplin led the majority of survey participants to become desensitized or complacent to this method of warning.  This suggests that initial siren activations in Joplin (and severe weather warnings in general) have lost a degree of credibility for most residents – one of the most valued characteristics for successful risk communication.  

Finding #2e:  Nationally, 76% of all NWS Tornado Warnings, in their totality, are false alarms.  This means 24% of all tornado warnings are eventually associated with an observed tornado –indicating limited skill in differentiating between tornadic and non-tornadic events; however, 68% of EF0-1 tornadoes receive advance warning of near 12 minutes, while 94% of EF3-5 tornadoes receive advance warning of near 18 minutes, indicating an ability to better detectstrong/violent tornadoes.9  Just over half (54%) of all severe weather warnings coincide with a severe weather event, indicating moderate skill in distinguishing between severe and non-severe thunderstorms. 

Recommendation #2:  To improve severe weather warning response and mitigate user complacency, the NWS should explore evolving the warning system to better support effective decision making.  This evolution should utilize a simple, impact-based, tiered information structure that promotes warning credibility and empowers individuals to quickly make appropriate decisions in the face of adverse conditions.  This structure should:

a) lessen the number of risk signals processed before protective action is taken (finding 2b)

b) provide a non-routine warning mechanism that prompts people to take immediate life-saving action in extreme events like strong and violent tornadoes (finding 2d).

c) be impact-based more than phenomenon-based for clarity on risk assessment (finding 2a)

d) be compatible with NWS technological, scientific, and operational capabilities (finding 2e)

e) be compatible with external local warning systems and emerging mobile communications technology (finding 2a)

f) be easily understood and calibrated by the public to facilitate decision making (finding 2a)

g) maintain existing “probability of detection” for severe weather events (finding 2e)

h) diminish the perception of false alarms and their impacts on warning credibility and response (finding 2c)

"Probability neglect" - and why rare, scary outcomes effect us so

http://www.slate.com/id/2303168/

Cass Sunstein writes:

Dreadful possibilities stimulate strong emotional responses, such as fear and anxiety.  Fortunately, most high-consequence negative events have tiny probabilities, because life is no longer nasty, brutish and short.  But when emotions take charge, probabilities get neglected.  Consequently, in the face of a fearsome risk, people often exaggerate the benefits of preventive, risk-reducing, or ameliorative measures.

 In both personal life and politics, the result is harmful overreactions to risks. One salient manifestation of probability neglect is that in two situations involving the same dreadful possibility, one much more likely to unfold than the other, individuals may value risk elimination nearly equally even though probabilities may differ by a factor of 20 or more.  People focus on the bad outcome itself, and are inattentive to how unlikely it is to occur – hence their overreaction when the risk is low.

False positive HIV test shut down porn industry

http://www.nypost.com/p/news/national/porn_industry_back_in_biz_after_JBe2VTU3PK4heeg8mpicJO

http://www.thedailybeast.com/articles/2011/09/02/porn-hiv-scare-closes-down-industry-are-male-sex-performers-to-blame.html?obref=obinsite

Police lineups and avoiding false positives

http://www.nytimes.com/2011/08/29/us/29witness.html?hpw

Medical tests can do more harm than good

http://www.thedailybeast.com/newsweek/2011/08/14/some-medical-tests-procedures-do-more-harm-than-good.html

CT Scans and lung cancer diagnosis

http://www.washingtonpost.com/national/health-science/ct-scans-for-lung-cancer-triggers-debate/2011/08/10/gIQASTbhHJ_story.html?hpid=z2

More mammogram controversy

http://www.msnbc.msn.com/id/43829024/ns/health-cancer/

"Half of women screened annually in their 40s will have a false alarm on a mammogram, he said -- meaning the test shows something suspicious that turns out to be harmless. Follow-up biopsies can be painful, expensive and carry a small risk of infections or other adverse effects."