3 ms·

from a random paper from 1995 https://academic.oup.com/jnci/article/89/13/939/2526258 https://academic.oup.com/jnci/article/89/13/939/2526258 << A total of 70

from a random paper from 1995 https://academic.oup.com/jnci/article/89/13/939/2526258 https://academic.oup.com/jnci/article/89/13/939/2526258 << A total of 704 cases of childhood ALL were identified. Among 0-4 year olds, the relative risks (RRs) of ALL for birth order positions 1, 2, 3, and 4+ were 1.00 (reference), 0.85 (95% confidence interval [CI] = 0.68-1.07), 0.91 (95% CI = 0.66-1.25), and 0.57 (95% CI = 0.30-1.06), respectively ( P for trend = .09).>> <<Children born second or later in the birth order had an increased risk of AML (RR = 1.53; 95% CI = 1.01-2.32) compared with firstborns. >>

ithilglin909 8y ago
Exposure to siblings might not be helpful, since those children, particularly young ones, are probably subject to the same environmental factors/presence (or lack thereof) bacteria and viruses.
- WhompingWindows 8y ago
  You may have misunderstood his rationale. The OP article suggests that kids need to have early infections and less clean environments in the first year, as later dirtiness can trigger a mutation that incurs leukemia. The parent comment says: well, if you have an older sibling, you should be more likely to be exposed to dirty stuff, since they're in/out of the house, picking up dirt, kissing dogs, getting sick from daycare, etc.
  - kevin_thibedeau 8y ago
    The mutation is already present. Per the article, the proposed trigger is an immune system that hasn't been desensitized to common environmental pathogens during early childhood.
ravitation 8y ago
There are a couple of cited studies in that paper that show different relationships between birth order and relative risk, but this specific study happens to indeed show an inverse relationship between relative risk and birth order. That second quote is about AML, which is a different form of leukemia than the one discussed in the paper published today.

ithilglin909 8y ago

Exposure to siblings might not be helpful, since those children, particularly young ones, are probably subject to the same environmental factors/presence (or lack thereof) bacteria and viruses.

WhompingWindows 8y ago
You may have misunderstood his rationale. The OP article suggests that kids need to have early infections and less clean environments in the first year, as later dirtiness can trigger a mutation that incurs leukemia. The parent comment says: well, if you have an older sibling, you should be more likely to be exposed to dirty stuff, since they're in/out of the house, picking up dirt, kissing dogs, getting sick from daycare, etc.
- kevin_thibedeau 8y ago
  The mutation is already present. Per the article, the proposed trigger is an immune system that hasn't been desensitized to common environmental pathogens during early childhood.

ravitation 8y ago

There are a couple of cited studies in that paper that show different relationships between birth order and relative risk, but this specific study happens to indeed show an inverse relationship between relative risk and birth order. That second quote is about AML, which is a different form of leukemia than the one discussed in the paper published today.