An investigator into the life expectancy of IV drug abusers divides a sample of patients into HIV-positive and HIV-negative groups. What type of data does this division constitute?

Social & Preventive Medicine

An investigator into the life expectancy of IV drug abusers divides a sample of patients into HIV-positive and HIV-negative groups. What type of data does this division constitute?

A study is to be conducted with regards to the fat content…

'There has been a gradual increase in number of non-communicable disease cases…

All of the following are done to remove Confounding except