Handout - 6 slides per page - Maine Indoor Air Quality Council

3/17/2012Apparently the Stork Does BringBabies and Other Amazing“True” Findings!(How to Evaluate ScientificResearch)MIAQC Annual Conference - March 21, 2012Jonathan Klane, M.S.Ed., CIH, CHMM, CETand Ivan Most, Sc.D., P.E.Quick Overview (of session):• Quick overview• Learning objectives• Disclosures• Stork and babies study• Epi 101• Case 1: Cleveland cluster (Stachy and babies)• Case 2: Smoking helps marathoners?• Case 3: Caffeine and breast cancer link?• Case 4: Speed to outpace Grim Reaper?• Questions?Learning objectives:By the end of the session you may be able to:• Compare and contrast an association fromcausation;• Explain why the “stachy” study was flawed;• Give examples of how science reported inthe popular media can be wrong; and• Evaluate scientific research objectively.Disclosures:• Ours:• Not paid to be here (free registration)• No connection to any study/researcher• Jonathan’s:• CIH and trainer• Teaches in Thomas College’s MBA Division• Ivan’s:• Professional Engineer• Teaches in UNE’s MPH ProgramStork and babies study:• Study by Robert Matthews (Aston U.)• Tested the “stork-birth” relationship• Plotted stork pairs vs. births in Europe• If disprove null hypothesis = no relation• Linear regression, t-test, test, ,pp=0.008• “Statistically significant” correlation• 1 in 125 due to chance• Other associations (like land area?)Storks vs. Babies 1965-801

3/17/2012Storks vs. Babies 1930-3636 inOldenburg, GermanyIs All Data Created Equal?• How do we know a data set is unique?• P < .05 in the Stork example- why is thatimportant?• What makes data significant?• Statistics• Which room has the taller attendees?• Cancer ClustersEpi 101• Types of Studies• Correlate- Descriptive Studies• Case/Control• Retrospective/prospective• Causal- Clinical – Laboratory• Population Studies (Generalize?)• Random Selection• Confounding and bias• Case studies ( Generalize?)Examples• Case 1: Cleveland cluster (“stachy” and AIPH in10 babies)• Case 2: Smoking helps marathoners?• Case 3: Caffeine and breast cancer link?• Case 4: Speed to outpace Grim Reaper?Case 1: Cleveland Cluster• 1993-9494 study• 10 babies w/ AIPH• Correlation w/ “stachystachy” ( (s.atra)• CDC Review –“problems”:• Not AIPH• OR inflated by multiple factors• Non-blinded investigator over sampled intest homes (more samples andaggressively)• “Water damage” undefined/inconsistent• No previous data AIPH w/ stachy• Conclusion: No relation., why?Case 2: Smoking HelpsMarathoners?• Study in CMA Journal• Smoking boosts lung volume, Hgbstimulates weight loss, too• These improve running performance• So, smoking improves running• Spoof article, cherry-picked data• “evidence if you look hard enough”• Ask, “evidence really applies?”• >lung vol, Hgb signs resp. problemssmokers, vs. adaptation in runners2

3/17/2012Case 3: Caffeine and BreastCancer Link?• 2008 Harvard study of 38,432 women• 3 patterns “statistically significant”• 2cm.”• 50 different poss. caffeine-cancer cancer links• 1 of 20 tests will randomly give false +• So, expect ~2.5 false positives• “Fishing expeditions” large data pool• Best - further research needed• Single question or small numberquestionsCase 4: Speed to Outpace theGrim Reaper?• Receiver operating characteristics (ROC)curve analysis• 1,705 men 70 and older• Average walking speed of 0.88 m/sec• 266 study ypparticipants pdied• No deaths speed >1.36 m/sec (~3 mph)• ROC speed 0.82 meters/sec (~2 mph)resulted in the highest sensitivity• Grim Reaper's preferred walking speedis 0.82 meters per second underworking conditions• Grim Reaper’s max speed = 1.36 m/sec• Walk >1.36 m/sec to outpace GR !Article ThermometerBest• Well designed ClinicalStudy• Clinical Study somebias• Well designeddescriptive study• Descriptive studyquestionable statistics• Personal OpinionWorstCurrent Articles• Objective of Media• Objective of Science• Let’s take a current article• How would you evaluate its quality?• What’s missing?Portland Press Herald Article• http://www.pressherald.com/news/eating-any-red-meat-raises-risk-of-death-study-reports_2012-0303-13.htmlQ and A• Would you change how you read thenewspaper or view blogs?• Sources??• The Web??3