Final answer:
The relative risk of contracting TB in smokers compared to the general population is calculated by dividing the incidence of TB in smokers by that in non-smokers. Smokers have a weakened respiratory and immune system, significantly increasing their susceptibility to infectious diseases like TB.
Step-by-step explanation:
The relative risk (RR) of contracting tuberculosis (TB) in smokers compared to the general population can be determined by comparing the incidence of TB in the population of smokers to that in the non-smoking population. To calculate the relative risk, the incidence of TB in the exposed group (smokers) is divided by the incidence of TB in the unexposed group (non-smokers).
Research has shown that smoking is a major cause of various diseases, including respiratory diseases, cardiovascular disease, and cancer. Smoking damages both the respiratory and immune systems, making smokers more susceptible to infectious diseases including TB.
For example, smoking more than 20 cigarettes a day has been found to increase the risk of infectious diseases by as much as four times compared to non-smokers. Thus, smokers are likely to have a higher relative risk of contracting TB than the general population.