A case-control study was conducted to identify exposures associated with a neurologic disorder in adolescents that is characterized by headaches and in a few severe cases, seizures. Cases (persons with the neurologic disorder) were compared to a randomly selected control group of adolescents without the disorder from the same schools the cases attended. The results of the study showed that the odds ratio for the disease, comparing those who played video games every day to those who did not play video games every day (the exposure), was 2.1. The researchers also found an odds ratio of 0.60, comparing those who regularly read books (other than school textbooks) to those who did not.

How would you interpret the odds ratio for the book reading exposure?