In a case-control study, the cases were found to be consuming zarda pan more frequently than controls and the difference was statistically significant. It indicates:
Case-control study that looks backward in time from final disease outcome to potential cause. 
In it, groups of affected individuals (cases) and unaffected individuals (controls) are compared to the extent of their exposure to some suspected risk factor. 

Key points 
In a case-control study,  if the outcome was statistically signiﬁcant, there is an association between cases and controls.
Soben Peter 
Essentials of preventive and community dentistry 
4th edition
Zarda pan is the cause of the disease
The incidence of the disease was more in those consuming zarda pan
The disease can be cured if zarda pan is stopped
An association exists between zarda pan and disease