repeated measures vs time series What is the difference between a time series design and a repeated measures design?
Is it correct to say time series is a kind of repeated measures design?
 A: An interrupted time series design includes at least three measurements before and at least three measurements after an intervention (See definition from Cochrane). Otherwise, it is considered a before and after study (See AHRQ taxonomy). A before and after study (also known as pre-post study) is "a simple example of repeated measures" (Study Designs and Their Outcomes, pg. 111). It is also the case that "Time  series designs can be repeated-measures designs" (pg. 110), so it seems reasonable to think of a time series study as a type of repeated measures design.
Cochrane groups time series and repeated-measures studies together in its good practice data extraction form, meaning the two study types have the same structure for data extraction purposes, and here is another published example that refers to time-series studies as a repeated measures design. While time series and repeated measures designs may overlap, the most common example of a 'repeated measures design' seems to be one in which all subjects receive multiple interventions and serve as their own controls (without three measurements before and after the intervention(s). Another characteristic of time series studies, according to the AHRQ taxonomy, is that "The investigator(s) does not assign or have control over the intervention/exposure."
