Modern media is literally filled with alarming figures: “40% increase in risk”, “40% increase in the disease”, “40% of patients are at high risk”. It sounds scary, although this loud statement may hide a much more prosaic reality. When we read or hear about a sudden jump in danger, it is always worth wondering: what exactly do these percentages mean and how close to reality are the data presented?
The article will tell you how often manipulations with numbers are used in news materials about health using the example of “40%”. We'll look at why it's worth distinguishing between relative and absolute risk, how to take numbers out of context, and how marketers and journalists enhance the effect of news. In conclusion, we will offer a simple algorithm that will help you not to panic and critically evaluate statistics in the media.
1. Headlines and emotional drive
The first thing that greets us on a news portal or social media feed is the headline. Lights of numbers and words that cause alarm: “40% more chances of getting sick,” “40% of complications,” etc. This approach is used to grab attention and encourage the reader to click on the article.
Usually behind the big claim is a modest study or testing with a small sample. For example, if scientists were able to demonstrate an increase in the frequency of symptoms from 5 cases per 100 people to 7 cases per 100 people, they would get a relative increase of 40%. It would seem impressive. But in fact, the absolute difference is only 2 people out of a hundred.
2. Relative and absolute risk
The key concept in assessing health statistics is two opposing but complementary terms:
- Absolute risk – difference in the actual number of cases of disease or complications.
- Relative risk – a ratio indicating how many times more often or less often an event occurs compared to the initial level.
Let's look at the example of “40%”. Let’s say that out of 1,000 people 10 are sick, and after the intervention this figure becomes 14. Then:
- The absolute risk increased by 4 cases per 1,000 people (from 10 to 14).
- The relative increase was 40% (4/10 × 100%).
If we initially had 1 patient out of 100 people, but it became 1.4, in relative terms this is the same 40%, but the absolute value remains at the level of one person or a little more. Sounds different, right?
3. How “40%” is hidden behind beautiful numbers
Statistics manipulators often operate in the following scenario:
- They take a distant indicator (for example, data from a small study or regional results).
- Convert abstract numbers into percentages, enhancing the impression.
- They do not explain the context: baseline, sample size, duration of observations.
- Mixes the results of different groups and makes generalized statements.
Let's take a quote from a pseudoscientific press release: “Drinking the new drink increases the risk of cardiovascular complications by 40%!” Upon closer examination, it turns out that in the control group there were 5 cases of exacerbations per 1,000 people per year, and in the experimental group - 7. The absolute increase is measured in two events per thousand people. No one will write “2 additional cases,” but the flashy headline “40%” works great on emotions.
4. The importance of context and sample size
Too often we don’t ask the question: “How many people participated in the study?” Small samples are prone to statistical fluctuations, and one or two non-standard reactions from a participant will dramatically distort the picture. Let’s say the study included 25 people, and two received an unexpected complication - that’s an “increase of 40%” compared to last year, when there were only one and a half people (relatively speaking).
In addition, it is important to consider the time period. A 40% increase in one month or quarter is not the same as in six months or a year. And if within a week, then this is almost absurd news without normal justification and representativeness.
5. When numbers replace meaning
Sometimes authors of health articles not only play with relative and absolute risks, but also take indicators out of scientific work, combining completely different groups of patients. One might find that “40% of people in the trial group recalled unpleasant side effects,” but upon closer inspection, one might find that the study was conducted on two categories: older and younger volunteers with different dosages of drugs. By mixing everything together, the creators of such news achieve the most frightening effect.
Example:
- In the first group (50 people), adverse reactions made themselves felt in 10 people (20%).
- In the second group (30 people), 12 people (40%) suffered adverse manifestations.
In total, we see in the article: “40% of trial participants noted side effects.” However, the journalist does not specify that 40% is an indicator for only one of the two groups, and not the overall result of the experiment.
6. The influence of headlines on reader behavior
When a person reads “40% risk of complications,” an alarm goes off in the subconscious, and he begins to look for a way to protect himself. This could be paid examinations, contacting specialists, purchasing additional supplements, and so on. The news itself provokes a wave of conversions: more visits to medicine, more viewing of advertising, more traffic to the resource.
If we were honestly told: “Two out of a hundred people have side effects,” our perception would be completely different. We would have been calmer, asked clarifying questions, and looked at the research in more detail.
7. Simple Rules for Critical Reading
To avoid falling victim to sensationalist headlines and inaccurate interpretations, here's a quick checklist:
- Check the source. Is this publication reliable, are there links to scientific journals?
- Estimate sample size. From several tens to hundreds or thousands - this is important for reliability.
- Ask about baseline prevalence. From what number of cases is the percentage change calculated?
- Compare absolute and relative indicators. How many additional cases were there per hundred or thousand people?
- Check your time frame. For a week, for a month, for a year?
- Look for alternative opinions. Comments from other experts, meta-analyses, reviews.
8. An example of thoughtful analysis of “40%”
Let’s imagine a fictional news story: “New study: Drinking green tea increases the risk of anxiety disorders by 40%.” Let's break it down step by step.
- Baseline stats: 5 out of 200 volunteers in the control group reported increased anxiety.
- In the experimental group (also 200 people) there were 7 of them.
- Relative growth: (7–5)/5 × 100% = 40%.
- Absolute change: 2 additional cases out of 200 people or 1% of all participants.
- Conclusion: for every 100 people, the risk of anxiety increases by 1% - a figure that can almost be called statistical noise.
However, the headline “40%” looks much louder and more dangerous than “1 additional case in a hundred.”
Conclusion
Misinterpretation of statistics can provoke a wave of unfounded fear and lead to unnecessary actions - from worry to pointless spending on examinations. Learning to read the numbers correctly means protecting yourself from media tricks and making decisions based on your real level of risk.
Remember that proportions and numbers taken out of context are often misleading. Instead of a panic reaction, it is better to take a few simple steps: check the source, calculate absolute numbers, compare groups and make sure the study is representative. Then the headline “40%” will no longer be a scary dream for you and will turn into a fair statistical information.
