Hi Chuie, I would reshape your current wide data to long data as such school teleclinic time count A Yes 0 50 A Yes 1 60 A Yes 2 13 A Yes 3 30 B No 0 151 B No 1 122 B No 2 155 B No 3 16 where time=0=pre, ..., time=3=after ED count(2016) and model by Poisson Regression. Your outcome variable will be count. The independent variables will be teleclinic, time and teleclinic*time and specify them as categorical variables. The interaction term will test if the effect of teleclinic on your outcome variable differs at each time point. If overdispersion exists, you will have to try to model by other distributions i.e. Negative Binomial Regression, generalised poisson regression. Please refer SAS online documentation or Google for further information. HTH.
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