From a news article titled Having OCD May Triple a Person's Odds for a Stroke:
Dr. Larry Goldstein, chairman of the University of Kentucky department of neurology in Lexington, reviewed the study findings. Goldstein pointed out that the actual risk of stroke among OCD patients is quite low. "Although the relative risk of ischemic stroke is approximately three times higher in those with a history of OCD, the absolute risk is small, less than 1% over the course of the follow-up period," he said. That translates to one additional stroke over the follow-up period among those with OCD. Goldstein also said that the findings may be affected by factors that the researchers could not control for, which could weaken the link they identified. He pointed out that there was no assessment of the types or effectiveness of risk factor controls over time in reducing stroke odds. The study was conducted in Taiwan, and more research would be needed to learn if the results would be similar in other populations, Goldstein added. "Nonetheless, the results should prompt further study of the relationship between OCD and stroke risk," he said.
I cannot understand the meaning of the sentence in bold, and would be very grateful for a simple-language explanation.
There was no "assessment of the types of risk factor controls" or "assessment of the effectiveness of risk factor controls". Am I right in reading it thus? But what does it mean?
And what part of the sentence does "over time in reducing stroke odds" refer to? I cannot parse the whole sentence, it's breaking up for me. I'm not a native speaker of English so maybe I'm missing something.