At medical schools, pharma companies, and even at the FDA, biostatisticians and clinical researchers recognize that retrospectivedata when treated with appropriate bias-controlling statistical methods, can in fact be reliable, particularly as it points to direction of influence and the general magnitude of effect.
The article said retrospective research data from hospitals in Ohio and Missouri noted that failing to get regular breast screenings often left these women more likely to discover cancer at an advanced stage and the delay resulted in larger tumors and a worse prognosis once the cancer was uncovered.
While other research has been done in this area, it has tended to be retrospective - looking back at the event leading up to an outbreak - rather than using that data to try to look ahead to the next one, they said.