Ahlgren, and Hammarstrom, 2004; Palmer et al., 2003; Thorbjornsson et al., 2000; Leino-Arjas, 1998), even after adjustment for other covariates. Furthermore, smoking has been identified as a risk factor for exercise-related injury in women (Gilchrist et al., 2000).
The mechanisms by which smoking increases the risk of injury warrant detailed investigation. Hier and Eide (1997) proposed a number of these, including reduced regional blood flow to working tissue, metabolic and circulatory effects, and neuromuscular effects. Furthermore, smoking may limit the ability of the recruit to maintain healthy bone and to repair tissue micro damage, which may lead to chronic injury during the repetitive stresses imposed during basic training.
High rates of attrition are costly to the military, and a general goal of recruiting policies is to screen out persons with a high likelihood of early attrition. Attrition at 12 months or at the end of specialty training is the most costly type of attrition, because training expenditures are at their maximum and enlistees have not yet contributed any productive man-hours in their jobs or units. Attrition at 3 months is somewhat less costly because of smaller training investments, while attrition at 36 months (or even 24 months) is less costly because trained man-hours have recouped at least some of the initial training investment.
Several recent studies have assessed the effect of cigarette smoking on first-term attrition. Studies were carried out for the Air Force (Klesges et al., 2001), the Army (Strickland, 2004), and the Navy. The Air Force study found that 12-month attrition rates were 19.4 percent for smokers compared with 11.8 percent for nonsmokers. The authors state: “The results of the current investigation suggest that smoking is the single best indicator of premature discharge over one year of training from the U.S. Air Force” (Klesges et al., 2001:9). This study estimated that the higher attrition rate of preservice smokers represents $18 million in higher training costs annually for the Air Force.
We think the Air Force study did not use the correct methodology to arrive at this estimate. We assume that the average cost of training per recruit up to 12 months is $20,000. Applying the formulas presented in Chapter 3, we estimate that the cost of attrition due to smoking (given the Air Force attrition rates and recruiting statistics) would be closer to $38 million per year. However, this is only half of the cost analysis. In order to determine whether screening out smokers would be cost-effective (ignoring, for the time being, the question of whether smokers could be identified in an operational screening environment), we have to also consider