The study presented the severity of effects of cigarette smoke on non-smoking wives of their smoking husbands. This was discovered in research that analyzed factors including cigarette smoking of husbands, alcohol consumption of husbands, and profession in how they affected the health of women, specifically the spouses of those husbands. There were no real correlations to be made with alcohol and health, but there was a noticeable correlation between smoking in husbands and the prevalence of lung cancer in non-smoker wives. Continued exposure to cigarette smoke from husband increased mortality from lung cancer by almost twofold according to the data. There was also a higher prevalence of lung cancer mortalities in more agricultural families vs. those in which the husband had an urban employment. This was attributed to the amount of time the more agriculturally based couples remained in contact with each other daily vs. the amount of time the more organized families operated.
What was probably the most interesting about this study was just how numerous the deaths due to lung cancer among women were according to figure 2 of the article. Only fifteen percent of Japan's female population smokes, and yet lung cancer is such an issue among this population. This could probably attest to the fact that second hand smoking from spouses is a real and dangerous issue, as it could be the missing link to explain why there were so many cases of women with lung cancer despite so few actual women who smoke.
This type of study design restricts potential bias because the habits of husbands and wives are acquired independently of each other. Also, there isn't solely a check comparison being made between lung cancer deaths and second hand smoking. There are several other health conditions that are recorded into the data as well to compare their specific rates of incidence in regards to a certain negatively stimulating factor. It not only proved that passive smoking was a problem, but a bigger problem compared to other common conditions. The sample size makes it possible to acquire a large amount of data and properly demonstrate the link between smoke and lung cancer that is being pushed forward.
The article, in my opinion, does a good job of creating the relationship of cause and effect between passive smoking and the prevalence of lung cancer among women. The data clearly depicts that prolonged exposure increased the numbers of Japanese women who died of lung cancer. The sample contained several thousands of people so it was a good representative of the Japanese populous. Perhaps the major flaw that does not really demonstrate the cause and effect relationship is the lack of any biological basis to link the cigarette smoke and the onset of lung cancer. The two are linked but it is never really physically described who. Understandably it may as well be common knowledge that cigarette's cause cancer. However, it would have definitely strengthened the report if there was a mention of the direct effects of the smoke on a person's body, even when not actually smoking it themselves.
I really enjoyed reading your thoughts on the study and your second paragraph especially interested me. I never thought of the numbers representing such a large population, I just read the results as numbers and took the article's opinion that it was a large percentage without trying to find out on my own so what you wrote actually made me go back to the article and check on my own.
ReplyDeleteThe only thing that I felt was lacking was the lack of numbers in your summary. I personally feel that especially in an experiment, showing any kind of statistic adds to the study as a whole, it makes me more receptive to the conclusions of an experiment. Even just the number of lung cancer victims out of the whole population would have been nice. Other than that one thing, your blog is really good.
Very good report on second hand or "passive-smoking". I was hoping to read something on why you thought agricultural worker's wifes were more likely to die of lung cancer than their urban counterparts. The last sentence in the last paragraph of your blog would really strengthen the articles ability to appeal to people. People don't like being told what happens without understanding how it happens... Keep up the good work!
ReplyDeleteYou raise important points noted in the article and note correctly that the biological effects of smoking were not discussed in the paper.
ReplyDeleteThis is one of Hill's criteria for causation. However, tobacco smoking is well established in the literature as being highly associated with lung cancer. I find your conclusion of cause and effect interesting. Yes, there are some of Hill's criteria specified in the article like temporality and dose-response. But while the relative risk of developing lung cancer was almost twice among those with heavy smoking husbands, it was still almost one-half to one-third that of direct smoking. Given that observation, one may argue that while an association was observed, it may not necessarily be enough to define it as a causal relationship. There are may be some confounding.
The other issue is Qn 3. This type of study is a cohort study with retrospective analysis. This type of study design is good for observing temporal relationships and one can evaluate multiple outcomes linked to an exposure. For example in this study, other outcomes were studied and it was found that no increased association with other cancers(cervix, stomach) or ischemic heart disease was observed.