You are correct, although you should say "The other 50% is living longer", since it's not necessarily "much longer".
When they refer in that article to a "number of studies" and say "those with RA and RARS had median survivals of approximately three to six years" it means that:
- In at least one study half the people survived less than three years and half survived more than three years.
- In at least one study half the people survived less than six years and half survived more than six years.
- In all the other studies, the 50% point was somewhere between three years and six years, i.e., three years was the worst median among the studies and six years was the best median among those studies.
I'm not sure why they add the word "approximately" since it's already a range.
What it doesn't tell you is how long people survived above (or below) that average, i.e., the best and worst outcomes for individuals. How long beyond six years did half the people in a study survive? Seven years? Ten years? Even longer?
That's the trouble with a brief report of statistics: you never know what it really means for
you, or any other individual.
As patients we also learn that statistics tend to give us a pessimistic view because they are based on patients treated years ago, before many of the current treatments were available or the best dosages of drugs had been found. Outcomes are better and better each year, and the statistics we read will eventually catch up. Until then, the statistics give us a rough idea how serious these diseases are but not the state of treatment and survival today, and they don't tell us what will happen to any of us individually.