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Science for journalists. The MMR vaccine: a series of failures in science reporting. The MMR vaccine : the serious consequences of bad science reporting. Combined MMR vaccine introduced. Measles vaccine introduced. MMR-autism link suggested. BSE : The perils of communicating risk.
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The MMR vaccine: the serious consequences of bad science reporting Combined MMR vaccine introduced Measles vaccine introduced MMR-autism link suggested
From lab bench to front page academic journal time space interest editorial fame funding prestige impact scientist press officer journalist
The Scientific Method Hypothesise Test Observe
Common sense (or rationalism) Hypothesise Conclude Observe
Experimental controls • Size of study • Statistical significance • Random selection • Measure other factors that might affect outcome • Unbiased observations: double-blind • Include subjects without vaccination • The more, the better • The likelihood that your results are luck • To avoid confounding factors • To detect possible confounding factors • Neither the experimenter, nor the subject knows whether they are in the control group (placebo treatment) Designing a good experimental study: Does the MMR-vaccine cause autism?
How would we design an experiment to test whether MMR causes autism?
Test Uchiyama et al. 2007 Scientific method Hypothesise Wakefield et al. 1997 Observe
How to read a scientific paper (on a deadline) • Title • A precise description of paper • Abstract • A summary of what they did and what they found • Introduction • The motivation and context of the research • Methods • Are they appropriate for the claims made? • Results • Tables, charts and lots of data • Discussion • The author’s views of what the results mean (or don’t)
“Scientists constantly tell us contradictory stories” http://www.dailymail.co.uk/health/index.html
How excited should I be? Holy crap! Phase III (marketability) Phase II (efficacy) Phase I human trials (safety) Animal tests In vitro tests Research announcement Hypothesis Yawn
Review articles: summarising the findings from literature 6/9/2010
Systematic reviews: the gold standard http://www.cochrane.org/
Dissecting a press release • Source? • Preliminary study from conference, not peer-reviewed • Is it a controlled experiment? • No comparison to non-diet drinks • What do we know about type of drink? • Very few details on drinks • What can you tell me about the subgroups? • Don’t know size of subgroups that drink a lot of diet drinks • Does the research prove diet drinks cause heart attacks? Can it? • Observational so can only show a link, not cause and effect • How do they know how much people drank? • Relies on self-reporting of diet, and only at start of study not as it goes along • What other risk factors were taken into account? • Controls for some factors but not all (family history of strokes? Other dietary habits? Weight gain?) • What was the increase in heart attack risk? • Is it 61% or 48%? • What is the baseline risk of heart attack? • Only relative risk given not absolute
Statistical analysis Uncertainty in Science: Why won’t scientist give you a straight answer? 1. STATISTICAL SIGNIFICANCE Test Hypothesise “There’s a high probability that your hypothesis is correct” Observe
Uncertainty in Science: Why won’t scientist give you a straight answer? 2. THE DEFINITIVE EXPERIMENTS ARE IMPOSSIBLE Do man made CO2 emissions cause global warming? The scientists say: “The balance of evidence suggests that there is a discernible human influence on global climate"
Uncertainty in Science: Why won’t scientist give you a straight answer? 3. IT’S IMPOSSIBLE TO PROVE THAT SOMETHING IS SAFE (BUT EASY TO SHOW THAT IT’S DANGEROUS)
Uncertainty in Science: Why won’t scientist give you a straight answer? 4. WE GENUINELY DON’T KNOW… YET What is the biological basis of consciousness? Why is there more matter than antimatter? Are there smaller building blocks than quarks? Is ours the only universe? Do mathematically interesting zero-value solutions of the Riemann zeta function all have the form a+bi?
Useful organisations and further info • Science Media Centre • There to help journalists who: • Need a news interview with a scientist • Have a question about a major science story • Need a background briefing on a scientific topic • Sense About Science • There to: • Respond to inaccuracies in claims about science • Help those who need expert help contact scientists about issues of importance • Brief non-specialists on scientific developments and practices
Useful resources: science publication databases PubMed US National Library of Medicine Free search tool for finding PEER-REVIEWED scientific studies The Cochrane Collaboration Library of systematic reviews in healthcare European Food Safety Authority Library of systematic reviews of nutrition and health claims for foods