Archive for June, 2011

Soldiers must be one of most special occupations in the world. In the past twenty years,US government has launched two wars against Iraq which was in 1991 and in 2003 respectively. Regardless of policies and purposes about the war stated byUS administration, the deaths of military members during the war can be clearly classified by the risks for individuals, in order to guide the public how much difference about the war there is between in the real world and in movies.

Samuel and Emily constructed a research to estimate the extent of individual risks according to the person’s branch of service, rank, age, sex, race and ethnicity. In the paper, the source data were provided by the Department of Defense on their website, with supplementary tabulations supplied by the Defense Manpower Data Center(2006). The death rates in the research were given for members of military who were deployed in Iraq. Their paper was posted at http://repository.upenn.edu/psc_working_papers/1. Welcome to visit it for more details.

According to the report, a total of 2321 deaths happened to US troops in Iraq between March 21st, 2003 and March 31st, 2006. This number includes all deaths whether combat-related or not. The total person-years of troops were estimated around 592,002 during this period. Therefore, the death rate by chance is approximately 1/255 per year, which is nearly less than half of the death rate for US civilian population in 2003 (1/119 reported by National Center for Health Statistics, 2006a). But if we look at the death rate for US men who aged 18-39 (1/654), it’s only 40% of that of soldiers inIraq. Of course, the death rate in Iraq is much lower than that in Vietnam, which was 56,838 deaths among members of military who had a total 2,608,650 person-years servicing time so that the final death rate was nearly 5.6 times greater than that in Iraq.

The highest death rate (1/118) can be observed in Marines when we compared them among different branch of service. The members in the active Army forces had three times higher risk of death than ones in Army reservists. The social scientists used to claim that the lower-ranking persons in military had more risk of death than higher-ranking ones, which could be demonstrated by the death rates of US troops in Iraq. In Marines, Lance Corporals had 4.8 times risk of death greater than Major/Colonel/General. If we looked at the age distribution of all deaths, soldiers who aged 17-19 had a death risk which was 4.6 times that of persons aged 50 or higher.

More comparisons and variability of death rates can be observed in this paper.


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By now, most Americans know that our nation is facing an obesity epidemic.  But, the problem is like the 500-pound gorilla in the room.  No one wants to take responsibility for their actions, so instead we point the finger at various other sources.  Does the McDonald’s Super Size Me movie ring a bell to anyone?  The latest blame game has cited employers as a reason for the rising obesity prevalence, specifically office jobs (1).  Let’s look at the facts.

As of May 2011, there were 153.7 million people employed in the United States (2).  Further, it has been reported that as adults, we spend half our waking hours at work (3).  So, maybe it makes sense to blame employers since the majority of Americans are spending the majority of their time working, chained to a desk.  But, let’s look at the prevalence of obesity in the U.S workforce compared to national statistics.

The NHANES 1999 – 2000 survey showed a 44% increase in obesity among U.S. workers from 20.4% to 29.4% with a modest increase of 4.5% for overweight workers and a 23% decline in the number of normal weight workers (4).  In the U.S. workforce, the proportion of overweight individuals is similar to the national prevalence of 34.2%; however, the prevalence of obesity is slightly less than the national average of 33.8% (5).  The smaller proportion of obese employees in the workforce may be due to the healthy worker effect, where employed individuals have lower morbidity and mortality rates (6).  However, it appears that the current workforce is still facing obesity issues.

Ok, so it does seem like obesity persists in the workplace.  While it is true that our nation is shifting to a more white collar, office job setting, I think employers really have another reason to take up this issue besides rising obesity rates.  Specifically, as employees’ waistlines are increasing, employers’ bottom line is decreasing.  Many studies have shown that as an individual’s BMI increases, so do medical costs and absenteeism, while productivity decreases (7, 8, 9).  Furthermore, a recent study indicated that a normal weight worker would have $114 of health care costs and 27.21 absent hours, whereas an obese worker would have $620 of health care costs and 35.52 absent hours (8).  However, these are not the only costs employers are losing.  It was also found that overweight and obese employees used more sick leave, disability time, and had more workplace injuries (10).  The profound financial implications of overweight and obesity in the workplace are leaving employers to deal with rising health care cost and declining productivity.  So, if things don’t change, we will either work ourselves to death, or become obese trying.


(1)    Church, T. S., Thomas, D. M., Tudor-Locke, C., Katzmarzyk, P. T., Earnest, C. P., Rodarte, R. Q., . . . Bouchard, C. (2011). Trends over 5 decades in U.S. occupation-related physical activity and their associations with obesity. PLoS ONE [Electronic Resource], 6(5), e19657.

(2)    U.S. Department of Labor Bureau of Labor Statistics.  (2011).  The Employment Situation – May 2011.  (Publication No. USDL-11-0809).  Washington, DC: U.S. Government Printing Office.

(3)    Engbers, L. H., van Poppel, M. N., Chin A Paw, M. J., & van Mechelen, W. (2005). Worksite health promotion programs with environmental changes: A systematic review. American Journal of Preventive Medicine, 29(1), 61-70.

(4)    Hertz, R. P., Unger, A. N., McDonald, M., Lustik, M. B., & Biddulph-Krentar, J. (2004). The impact of obesity on work limitations and cardiovascular risk factors in the U.S. workforce. Journal of Occupational & Environmental Medicine, 46(12), 1196-1203.

(5)    National Center for Health Statistics. (2010). Health, United States, 2010 Special Feature on Death and Dying. Hyattsville, Maryland.

(6)    Checkoway H, Pearce NE, Kriebel  D.  Research Methods in Occupational Epidemiology.  Second Edition.  New York:  Oxford University Press, 2004.

(7)    Aldana, S.G. and Pronk, N.P.  (2001).  Health Promotion programs, modifiable health risks, and employee absenteeism.  JOEM, 43, 36-46.

(8)    Bungum, T., Satterwhite, M., Jackson, A.W., Morrow, J.R.  (2003). The Relationship of body mass index, medical costs, and job absenteeism.   American Journal of Health Behavior, 2, 456-463.

(9)    Ricci, J.A. and Chee, E.  (2005).  Lost productive time associated with excess weight in the US workforce.  JOEM, 47, 1227 – 1234.

(10)Schmier J.K., Jones M.L., Halpren M.T.  (2006).  Cost of obesity in the workplace.   Scand J Work Environ Health, 32, 5–11.

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Baseball is a sport that is enjoyed in many nations around the world. Beyond the United States and Canada, baseball is also played professionally in several countries in Asia, Latin America and the Caribbean, and players from more than 50 nations have played in the Majors.

Life expectancy at birth (a composite measure of mortality experience of a population) has been shown to vary greatly by country. While it seems clear that economic factors play a major part in these differences, there is the obvious potential for independent genetic and cultural causes as well.

This led me and my colleague Steven Day to wonder if the relative mortality experience of baseball players from other countries would mirror that of the general populations in question. That is, would players from somewhere such as the Dominican Republic — which has a lower life expectancy at birth than does the U.S. — have higher mortality than U.S. players, or would it even matter? What about players from Canada, where life expectancy is actually higher than the U.S.? Would those players continue to experience lower mortality or would their participation in MLB alter their experience somehow? We hypothesized that players from first-world countries with high standards of living would display no differences in mortality compared to U.S. players, while countries from Latin America and the Caribbean (with their high crime rates and extreme poverty) would demonstrate higher mortality rates than U.S. players. This research is the basis for a poster we are presenting at the 3rd North American Congress of Epidemiology next week, on June 23, 2011.

To test these hypotheses we used data on all baseball players who debuted in MLB between 1900 and 1999. From these, we selected all the players from the 6 best-represented nations: Canada, Cuba, Dominican Republic, Mexico, Puerto Rico, and Venezuela. Since many of these nations did not have any players in MLB until the 1950s, the study period was limited to 1950-1999. We calculated age and decade-specific Standardized Mortality Ratios (SMR) using mortality rates from U.S. baseball players as the population comparison rate.

Results show that for the most part MLB seems to homogenize mortality among the players. SMR for all the nations except D.R. and Venezula were very close to 1.00 with confidence intervals that included 1.00. The SMR for D.R. was fairly high at 2.38, but the 95% confidence interval of 0.90 to 5.06 includes 1.00. Venezuela had significantly elevated mortality risk, with an SMR of 3.14 (95% CI = 1.10, 6.95).

Though we cannot be sure, we speculate that Venezuela’s increased mortality is the result of Third-World violence. The CIA Factbook warns would-be travelers against Veneuzuela’s high crime rate, particularly murders, for which Venezula is a world leader. That D.R.’s mortality rates were elevated and approached significance supports this idea, as they too have widespread poverty and a high crime rate, though to a lesser extent than Venezuela. Though it may be tempting to wonder why Mexico did not show an increase in mortality given its recent rise in violence, recall that this study was through 1999 only.

It seems then that the lifestyle of MLB — physical fitness, travel, money, fame, access to health care, etc. — pulls the mortality of players from most nations up or down to unity with that of players from the United States, an idea we intend to test further in the near future. If true, it is an important piece of the puzzle concerning mortality rates, athleticism, and economics.

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To the Occupational Epidemiology Summer 2011 Students.

I hope you’ll find this blog a valuable tool to expand your interest and knowledge of Occupational Epidemiology. Please feel free to add relevant information.

If you have a problem posting, it’s probably because of your sharing rights (so email me and let me know- Christina.M.Socias@uth.tmc.edu).

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