Go by the processing time updated on CIC website every week...if your processing time has passed by the ideal time, then CIC is awaiting additional security checks, background checks and authentication of documents.
If upfront medical is not done, then they are awaiting medical reports.
Ideally refusal and approval takes same time as every nationality has different processing time and you should look for your national processing time.
If refusal case is very strong like medically unfit/criminal record and forged documents submitted then its usually delayed as CIC updates A40 and A44 sections in database, which means candidate is prohibited from applying to Canada.
Be patient for atleast five weeks latest.