So my brain is just not understanding the difference between the two above. I am currently writing a literature review and have to explain the significance of what was found in the research.
The researchers did a six year observation cohort study of the use of pioglitazone including 2864 subjects with type 2 diabetes without established cardiovascular disease
They measured the effect of this drug at a baseline year with a Cox proportional hazard model and the time dependant use in each one year examination interval with a pooled logistic regression model.
Results were baseline use of the drug (n=493) did not show a statistically protective effect on primary end point (n=175 - primary endpoint being CVD event or death). Although it tended to reduce the risk. However pooled logistic regression analysis indicated a significant protect association of pioglitazone with the primary endpoint
The study also states the first one year period was used as a baseline to examine the effect of this drug on cardiovascular events and all cause mortality. Thus, patients who had any primary outcomes within one year after entry (n=26) or were not followed up over the year (n=30) were excluded. Finally a total of 2864 subjects were enrolled in the study.
The results from the cox analysis was limited to the baseline year in terms of pioglitazone use, so the researchers performed a pooled logistic regression anaysis and explored the association of time dependant use of pioglitazone with development of cardiovascular event or all cause death.
Herein 2864 subjects who enetered this observational study contributed to 11,952 person years thus the pooled data set consisted of 11,952 observations with 175 primary endpoints and a logistic analysis was performed on this pooled sample.
Sooo here is where I'm struggling. I know the Cox looks at two variables from time of study to the time of the event (right?) and the logistic regression looks at the two variables from time to event and takes into account other variables (meds discontinued, side effects etc) (right??)
I dont quite understand the significance of the baseline data particularly when both models state n=176 to primary endpoint. I feel so stupid, I have googled, youtubed, read the article over and over and over again and I still haven't been able to understand it properly. If someone could please help explain the above in laymans terms I would be forever grateful.