Male smokers had more lost workdays than female smokers, the study showed.
Almost 88,000 men and women (average age, 28 years) on active duty in the US Army were monitored for over two years.
The smokers had more lost workdays, and were admitted to hospital more frequently, than their non-smoking colleagues. Among the men, smoking increased the risk of being admitted to hospital for causes other than injury by almost a third; in women the equivalent increase in risk was 25 per cent.
The research showed that former smokers also had higher admission rates than non-smokers. Current smoking could be directly implicated in 7.5 per cent of hospital admissions in men and 5 per cent of those in women.
Lost workdays increased by 60% among men who smoked
The risk of lost workdays, excluding injury and pregnancy, was increased by 60 per cent among men who smoked and by 15 per cent among women smokers. Over 14 per cent of lost workdays among men and 3 per cent of those among women were directly linked to smoking. The rate of lost workdays as a result of injury was also higher among smokers, at 7 per cent among men and 54 per cent among women.
The authors point out that most employment research on smokers has focused on older populations, but that this study shows the adverse effects among young smokers, with the consequent cost implications for employers.
"It is remarkable that a single risk-factor could account for such a large proportion of hospitalizations and lost workdays, particularly over such a short period of observation," they conclude.