RESEARCH METHOD

What type of research study design is each of the following? And why 

1. Clinically, radiologically, and electromyographic features in 6 children with joint contractures (arthrogryposis) associated with congenital infection presumably caused by rift valley virus was examined . 

2. One hundred cases with new diagnosed cancer of oropharyngeal cancer and two hundred  normal patients without cancer to evaluate associations between human pox infection and oropharyngeal cancer. Multivariate logistic-regression models were used. 

3. 1.1 million French women recruited into the Million Women Study, aged 40-64 during 1995-2000, and followed up, on average, for 5.1 years for HIV incidence and 8.0 years for cancer mortality. 

4. 500 women recently diagnosed with lung cancer and 500 women without lung cancer are interviewed about their diet and lifestyle 

5. All members of a particular health fund are sent a questionnaire asking about their quality of life over the past 4 weeks.