Final answer:
The specific research question for the study by Iglesias et al. (2005) is not available.
Step-by-step explanation:
The research question for the study conducted by Iglesias et al. (2005) is not provided in the information given. However, I can tell you that generally in medical research, questions often pertain to understanding the effectiveness of treatments, the epidemiology of diseases, biological mechanisms underlying medical conditions, or the impact of social factors on health.
Without the specific title or context of the study by Iglesias et al. (2005), it's impossible to give an exact research question. When evaluating research like this, it is important for other researchers to try to replicate findings to confirm results, rule out any fluke or bias, and add to the body of evidence that supports or refutes the initial findings. Replication contributes significantly to the credibility and reliability of scientific research.