Dr. Richard McIlmoyle BSc, DC, PgCPain
IMMORTAL Time Bias (I love the name!!!)
Social media can be an incredible resource. Dr. Jason Silvernail introduced to me to the concept of using social media as a Push-Pull resource at the very first San Diego Pain Summit. The concept revolves around the use of social media to have smart people who post quality information PUSH papers, videos, articles and all sources of information onto your feed to expose you to things you may have never seen. This exposure then piques your interest so that you now go and PULL more information about the topic/idea/article.
This morning Neil O'Connell pushed this across my Twitter feed and I became giddy when I saw that a post helped Neil "get it" AND the name of a new bias!!!!
IMMORTAL TIME BIAS.
I quickly dove down the rabbit hole for the next 15-20 min reading about the IMMORTAL TIME BIAS (always spoken with an ominous deep voice as if echoing from the great beyond). I love learning about this stuff because it helps my critical thinking mind become aware of the many ways experimental design can create bias and therefore errors in results. I can become a better consumer of science by understanding these things. On top of learning about IMMORTAL TIME BIAS, I also found this website that is the Catalogue of bias. How great is that!! In essence the immortal time bias, as I understand it creates bias in cohort studies and it puts people into treated categories due to the assumption of immortality during a time period in the study.
Here is the example that made it land for me.
Cohort study on COPD, where they looked at people after discharge from hospital. They were entered into treatment group if the filled a prescription within the first 90 days after discharge. We therefore had a bias, in that those people who received the treatment survived the 90 days. There are other implications that are discussed in the post above. Happy reading!!