¶ … Smoking and Lung Cancer Cohort, cross sectional, and case-control studies are together known as observational studies. These studies are frequently the only feasible manner of analyzing certain problems (Mann, 2003). In this particular case, the observational studies shall concentrate on smoking together with lung cancer.

COHORT STUDY

This is the most appropriate manner of establishing the condition's prevalence and natural history.

Conducting Study

A group of individuals that do not have the desired outcome shall be selected. Several variables, which may be significant to the condition's development shall then be measured by the researcher. The individuals in the selected sample are monitored over a length of time to observe if they develop the desired outcome (lung cancer). For the two cohorts utilized, one group shall have actually been exposed to or been smoking while the other has not, thus serving as an external control (Mann, 2003; Chen et al., 2010).

Advantages and Disadvantages

Advantages

1. Given that potential causes are assessed by cohort studies prior to the occurrence of the outcome, the study is able to show that these "causes" come first before the outcome, thus evading the dispute regarding which is the cause and which is the effect (Mann, 2003).

2. Several outcome variables...

Where a particular outcome is unusual, then a potential cohort study is not efficient.
2. There is loss of various subjects to follow up.

3. In cases whereby there is comparison of two cohorts, one shall have been exposed to the agent of interest while one is not. The incapability of controlling all other aspects, which may vary between the two groups is the main disadvantage (Mann, 2003).

CROSS SECTIONAL STUDY

This is majorly utilized to determine incidence. Incidence corresponds to the quantity of cases in a given population at a given time (Mann, 2003).

Conducting Study

Cross sectional study shall be utilized to deduce causation. At a certain point, the subjects shall be examined to establish if they were actually exposed to the relevant cause (smoking) and if they were the desired outcome. This sets apart this kind of study from other observational studies. The investigator shall come up with the research questions and select the sample population then choose variables like smoking incidence of the study population. A means for contacting the study shall be formulated and then applied. The data shall be gathered and evaluated in this manner (Mann, 2003).

Advantages and Disadvantages

1. It is fast and cost…