Navigation Links
Poorly presented risk statistics could misinform health decisions
Date:3/15/2011

Choosing the appropriate way to present risk statistics is key to helping people make well-informed decisions. A new Cochrane Systematic Review found that health professionals and consumers may change their perceptions when the same risks and risk reductions are presented using alternative statistical formats.

Risk statistics can be used persuasively to present health interventions in different lights. The different ways of expressing risk can prove confusing and there has been much debate about how to improve the communication of health statistics.

For example, you could read that a drug cuts the risk of hip fracture over a three year period by 50%. At first sight, this would seem like an incredible breakthrough. In fact, what it might equally mean is that without taking the drug 1% of people have fractures, and with the drug only 0.5% do. Now the benefit seems to be much less. Another way of phrasing it would be that 200 people need to take the drug for three years to prevent one incidence of hip fracture. In this case, the drug could start to look a rather expensive option.

Statisticians have terms to describe each type of presentation. The statement of a 50% reduction is typically expressed as a Relative Risk Reduction (RRR). Saying that 0.5% fewer people will have broken hips is an Absolute Risk Reduction (ARR). Saying that 200 people need to be treated to prevent one occurrence is referred to as the Number Needed to Treat (NNT). Furthermore, these effects can be shown as a frequency, where the effect is expressed as 1 out of 200 people avoiding a hip fracture.

In the new study, Cochrane researchers reviewed data from 35 studies assessing understanding of risk statistics by health professionals and consumers. They found that participants in the studies understood frequencies better than probabilities. Relative risk reductions, as in "the drug cuts the risk by 50%", were less well understood. Participants perceived risk reductions to be inappropriately greater compared to the same benefits presented using absolute risk or NNT.

"People perceive risk reductions to be larger and are more persuaded to adopt a health intervention when its effect is presented in relative terms," said Elie Akl of the Department of Medicine, University at Buffalo, USA and first author on the review. "What we don't know yet is whether doctors or policymakers might actually make different decisions based on the way health benefits are presented."

Although the researchers say further studies are required to explore how different risk formats affect behaviour, they believe there are strong logical arguments for not reporting relative values alone. "Relative risk statistics do not allow a fair comparison of benefits and harms in the same way as absolute values do," said lead researcher Holger Schnemann of the Department of Clinical Epidemiology and Biostatistics at McMaster University in Ontario, Canada. "If relative risk is to be used, then the absolute change in risk should also be given, as relative risk alone is likely to misinform decisions."


'/>"/>

Contact: Jennifer Beal
healthnews@wiley.com
44-012-437-70633
Wiley-Blackwell
Source:Eurekalert

Related medicine news :

1. AGH Study Shows High Rates of Poorly Controlled Asthma Among Inner-City Pittsburgh Children
2. Long-acting beta-agonists most effective step-up therapy for children with poorly controlled asthma
3. Poorly understood cell plays role in immunity against the flu
4. Older people in assisted-living facilities sleep poorly
5. Connor Sport Court Lays the Ground for NBA All-Star Jam Session Presented by Adidas
6. Digital Signatures Presented at Electronic Document Management Conference
7. Compex , Leaders in Electronic Muscle Stimulators, Sponsors the Jelly Belly Cycling Team Presented by Kenda
8. Game Ready(R) Presented with Frost & Sullivan 2010 Product Differentiation Excellence Award
9. New Data from Caldolor(R) Study in Burn Patients to be Presented at 42nd Annual Meeting of The American Burn Association
10. Nine Healthcare Companies Named Finalists for Innovations in HealthcareSM ABBY Awards, to be Presented April 28th
11. Zimmer Receives Recognition for Health Economics Data Presented at 77th Annual American Academy of Orthopaedic Surgeons Meeting
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/30/2016)... ... April 30, 2016 , ... Saturday, April ... veterinarians’ global impact on public health. The World Veterinary Association (WVA) and the ... year have selected continuing education with a One Health focus, which emphasizes how ...
(Date:4/30/2016)... ... April 30, 2016 , ... Orlando-based Maximized Living has selected Dr. Nick ... in Rio. Under the care of Maximized Living doctors at the London Olympics ... showing, Maximized Living is sending the largest contingent of elite chiropractors to Rio to ...
(Date:4/29/2016)... , ... April 29, 2016 , ... ... Ten Footwear Foundation, the national charitable foundation serving the footwear industry, has broken ... volunteers representing more than 130 companies across 23 states during the months of ...
(Date:4/29/2016)... (PRWEB) , ... April 29, 2016 , ... On Tuesday, ... hospitals across the Southeast, celebrated the signature of Gov. Nathan Deal on SB 258, ... Geoff Duncan (R - Cumming), offers a 70% tax credit to individuals and corporations ...
(Date:4/29/2016)... ... April 29, 2016 , ... Conditions were ideal for Global ... Park on Sunday, with sunny skies, a light breeze and temperatures in the 60s. ... , The 5k Run and Walk and 1-mile walk were held to increase ...
Breaking Medicine News(10 mins):
(Date:4/27/2016)... 2016  Bayer Animal Health today announced that ... University of Florida College of Veterinary Medicine, is ... Communication Award (BECA). Brittany was selected from entries ... total of $70,000 in scholarship funds through the ... has provided a total of $232,500 in scholarship ...
(Date:4/27/2016)... , April 27, 2016 ... addition of the  "Global Anesthesia Disposables Market ... http://photos.prnewswire.com/prnh/20160330/349511LOGO ) ,The global anesthesia ... a CAGR of 4.03% during the period ... a major threat to patients, safety. Organizations ...
(Date:4/27/2016)... , April 27, 2016 ... USD 2.14 billion by 2022, according to a ...      (Logo: http://photos.prnewswire.com/prnh/20150105/723757 ) , ... affecting the efficiency and accuracy delivered by the ... demand for novel urinalysis instruments and consumables. For ...
Breaking Medicine Technology: