Epidemly and biostats - Assignment Example

To do this, they have to contact hospitals and physicians. This activity requires a vast amount of resources and staff in order to accomplish its objectives and goals. a) The conclusion reached may be incorrect because proportional mortality was used when cause-specific mortality rates were needed. Cause specific rates are applied when calculating deaths from a specific disease (Polit, 2010). Proportionate mortality is applied when calculating the number of deaths in relation to the total deaths or all deaths (100%) a) The number of deaths from lung cancer in carpenters in 1949–1960 was greater than the number of deaths from lung cancer in bricklayers during the same period.

SMR is often used to study the mortality in a specific occupation. From the data, carpenters have a higher mortality than brick layers during the same period. a)Reduce selection bias in the allocation of treatment. Treatment differences which are identified from nonrandomized trial designs possess methodological weaknesses. For example, cohort effects, selection bias and confounding. As such, the major purpose of a random assignment is to counter this methodological weakness. a)Avoid observer and subject bias.

A double blind experiment design tests a drug or treatment’s effect by using groups of control and experimental subjects whereby neither the investigators nor the subjects know which drug is being used on which group (Grove, 2007). Therefore, this design eliminates the issue of prejudgment which can distort the