Difference in difference method

[pailokesh]

Backgound

My research is on the quantum of repetitions of investigations in a tertiary care hospital setting. I have calculated the no of repetitions month wise for an entire year in two departments. I have carried out an intervention (educational lectures) in one department in an attempt to reduce the repetition. Now I want to analyse whether the intervention has had any impact on the repetitions. We presume that there is a decrease in repetition owing to the increase in knowledge with time. How do Ievaluate the same using SAS. Kindly help.

Regards and thanks.

[ballardw]

Do I understand you to say that you collected data without an analysis plan?

[PGStats]

Can you rephrase your question in plain language, please? Expressions such as "difference in difference" and "quantum of repetitions of investigations" and "impact on the repetitions" are very fuzzy to me.