Every day, heart patients are bombarded with reports of “new studies” and “startling scientific findings.” One day, Vitamin D, fish oil, red wine and long- distance running are touted as good for you – and the next month, the media is warning against them. Not sure what to believe?
It’s not always simple to sort out. But, Cleveland Clinic heart surgeon Marc Gillinov, MD, and cardiologist Steven Nissen, MD, say a little homework can pay off. Here, they offer five tips for uncovering the truth in medical headlines:
1. Don’t jump to conclusions every time you hear a news report – Why? Careful examination of the headlines often uncovers misinformation, debates and disagreements.
It’s important to understand that not all studies are created equal, and not all evidence carries the same scientific weight. You must learn to judge the quality of the evidence.
2. Be a detective: ask questions! – To understand medical research, there are three important questions you need to ask:
- What are the odds that the study results are incorrect, or simply due to chance? Chance always plays a role. The real question is “What is the likelihood that the study results were caused by chance alone?” Scientists use a number called a P-value to describe the probability that research findings are incorrect, a result of chance. While most news reports won’t include a P-value, most medical websites will. The smaller the p value, the more likely the study is reliable. Anything less than P = 0.05 is considered statistically significant, but definitive studies often have p values less than 0.01.
- How large is the treatment’s effect? One scientific number used to evaluate the magnitude of a medicine’s or therapy’s benefit is a hazard ratio, or HR. A hazard ratio less than 1.0 indicates that the new therapy is helpful. The smaller the number, the greater the benefit. For example, a HR of 0.82 indicates that the therapy reduced risk by approximately 18 percent.
- How many people would we need to treat to see a benefit? Consider: We need to treat 10,000 people with a medicine to prevent a single heart attack over a five-year period. In this case, the number of people we would need to treat to see a benefit is very large – too large unless the drug has absolutely no side effects and is very inexpensive.
3. Know what makes a study more likely to be trustworthy – No more talk of numbers. Look for these three factors that indicate a study is likely to be reliable: 1) It is a randomized controlled trial (RCT), which is the gold standard of evidence-based medicine. 2) It has been published. This ensures the study has been reviewed by experts who look for flaws in design or conduct. 3) It appears in a top journal. The finest medical journals publish fewer than 5 percent of all submitted articles. The most prestigious general journals include the New England Journal of Medicine, the Journal of the American Medical Association and the Lancet. In cardiology, the two top journals are Circulation and the Journal of theAmericanCollegeof Cardiology.
4. Understand factors that make research less reliable – Research is less reliable if: 1) It is an observational study or meta-analysis (vs. a RCT). 2) It has been presented only in abstract form (meaning presented at a scientific meeting, but not necessarily published). 3) The study doesn’t appear in a top journal.
5. Talk to your doctor – Anytime you feel sorting out the data yourself is too difficult or you have questions about new research that calls your current treatment plan into question, talk to your doctor. Before stopping any medication or treatment, ask him or her if the study applies to you and if it appears reliable.
Learn more about analyzing medical headlines by checking out Heart 411: TheOnly Guide to Heart Health You’ll Ever Need, the new book authored by Drs. Gillinov and Nissen. This new book cuts through the confusion to give you the knowledge and tools you need to live a long and heart-healthy life.