tag:blogger.com,1999:blog-3023557377783456784.post3783202394804057939..comments2013-07-15T10:01:56.519-07:00Comments on Intro to Public Health student blog - Leslie MacManus: Blog Assignment 2 - Smoking and Lung CancerLeslie MacManushttp://www.blogger.com/profile/04902431346339263007noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-3023557377783456784.post-52720342363801990972013-07-15T10:01:56.519-07:002013-07-15T10:01:56.519-07:00Smoking is injurious for health it may cause lung ...Smoking is injurious for health it may cause lung cancer. For more detail see my blog <a href="http://lungcancersymptomsx.com" rel="nofollow">Lung Cancer Symptoms</a>Anonymoushttps://www.blogger.com/profile/09947915944918498425noreply@blogger.comtag:blogger.com,1999:blog-3023557377783456784.post-85834831964278285002013-02-11T19:18:51.386-08:002013-02-11T19:18:51.386-08:00Thanks for your post!
For decades, public health...Thanks for your post!<br /><br /><br />For decades, public health advocates have attempted to link cigarette smoking and lung cancer. The attempt to make a causative link between smoking and lung cancer has been stymied by the long timespan prior to the development of lung cancer, the relative rarity of the disease and the numerous confounding factors that are concurrent in individuals who smoke. This landmark prospective cohort study sought to show an association between second-hand (aka side-stream) smoke exposure, lung cancer incidence, overall mortality and lung cancer attributable mortality. For more information about criteria of causation please see the Bradford Hill criteria: http://en.wikipedia.org/wiki/Bradford_Hill_criteria<br /><br />The study designers utilized a cohort design in order to analyze the risk associated with second hand smoke exposure (risk ratio = relative risk). Cohort studies are often difficult to accomplish due to the length of follow-up time, the overall cost of the study and the possibility of a large number of study participants to be lost to follow-up. In contrast, case-control studies identify cases (those with disease) and controls (those similar but without disease) and attempt to distinguish different rates of past exposure. This study sought to prove that smoke exposure was specifically related to an increase in lung cancer incidence, environment of residence is not a confounder of this relationship and that smoke exposure and lung cancer incidence has a dose response relationship (more smoke exposure causes more cancer). The authors further point out that considering their results, future comparisons of the health status between smokers and nonsmokers should control for the secondhand smoke exposure of nonsmokers.<br /><br />As you point out, the study sought to compare the association of husband smoking, other husband behavior and the lung cancer related mortality of their wives. Admittedly the downside to using a cohort analysis (taking a group and following them) is that you cannot control for all exposures. Ideally you would like to take a group of individuals and randomly exposure them to the agent of interest (here smoking) or placebo and see if there is any difference in the risk of developing the outcome (here lung cancer). For many hazardous exposures, this type of randomized control trial is unethical and/or not feasible. In this study the investigators are attempting to show that there is something unique to a particular husband behavior (smoking vs. alcohol use) that is causing an increase in lung cancer mortality. This goes to the distinction between showing an association between two things and then taking the next step toward proving causation. Which of the Hill criteria mentioned above do you think this study addresses?<br />Publichealth_Weaver_Gregory(TA)https://www.blogger.com/profile/00362466103919673148noreply@blogger.comtag:blogger.com,1999:blog-3023557377783456784.post-2552161570778549482013-02-09T21:00:59.748-08:002013-02-09T21:00:59.748-08:00I like the way you summarized the article so that ...I like the way you summarized the article so that the layperson could understand the results of the study. I would only add in some of the measurements such as p-values used in order to back your summary. Otherwise, nice work.Anonymoushttps://www.blogger.com/profile/14360713656134337076noreply@blogger.com