Occupational injuries comprise approximately one-third of all injuries sustained and can have a substantial economic impact due to lost income, compensation costs, long-term health problems, etc. [Wilkins and Mackenzie 2007, Boden and Galizzi 1999]. Risk and consequences of workplace injuries are not uniform across age groups. While injuries in older workers often lead to more disability [Silverstein 2008, Wegman, et al. 2004], injuries in young workers are more prevalent and can have a substantial impact on the rest of their work life [Silverstein 2008, Jackson 2001, Salminen 2004, Lewis, et al. 1998]. While older workers are currently the fastest growing worker group [Hobbs, et al. 2006], injured workers aged 16–24 years report significantly lower earnings in the following year [Breslin, et al. 2007]. Thus, identifying industry sectors with the highest injury risk within each age group, especially the extremes of work life, is important for development of effective preventive interventions.

This study included 168,671 adult participants (aged 18 and older) of the 1997–2009 National Health Interview Survey (NHIS), who were employed (i.e. worked for pay) in the week prior to the interview. Data were obtained from the Persons, Sample Adult, and Injury Episode NHIS files. Industry was classified using the National Occupational Research Agenda (NORA) sectors: 1) Agriculture/forestry/fisheries; 2) Construction; 3) Healthcare/social assistance; 4) Manufacturing; 5) Mining; 6) Services; 7) Transportation/communication/other public utilities; and 8) Wholesale trade/retail [NIOSH 2006]. The Services sector was chosen as a reference group due to having the largest proportion of workers across all age groups. Injuries captured by NHIS were those occurring within three months prior to the interview for which medical attention was sought. Injuries were classified as work-related if the participants responded “Working at a paid job” to the question about what they were doing at the time of injury. Work-related injury was treated as a dichotomous variable (yes/no). One injury event per individual was analyzed in cases of multiple events. Workers were classified into three age categories: 1) 18–25 years, 2) 26–54 years, and 3)55+ years. Because secondary data was used, participants’ signed informed consents were not obtained. This study was approved by the University of Miami Institutional Review Board for Human Subjects.

A total of 4,768 participants reported being injured; of these 1,484 were injured at work (Table I). These represent respectively 2,671,571(SD=47,683) and 837,649(SD=26,368) employed adults annually. In multivariable modeling, gender, race/ethnicity, NORA sector, and income-to-poverty ratio were significantly associated with work-related injuries for the overall sample (Table II). Of non-occupational factors, male gender had the highest association with workplace injuries overall (odds ratio=1.71;p<0.0001) and for age groups 18–25 (2.33;p<0.0001) and 26–54 (1.63;p<0.0001). For the overall sample, lower risk of injury was associated with Hispanic (0.55;p<0.0001) and other (0.57;p=0.0006) races/ethnicities. Similar associations were observed for age groups 18–25 and 26–54. Education was not associated with injury risk in any group, however it was left in the model as an indicator of socio-economic status. For workers 55+, only industry sector was associated with injury risk.

Across NORA sectors, the highest risk of workplace injuries for the overall sample was in Agriculture/forestry/fisheries (2.41;p<0.0001), Construction (2.38;p<0.0001), and Manufacturing (1.75;p<0.0001). Agriculture/forestry/fisheries and Construction were among the highest risk sectors across all age groups (age 18–25: 4.80;p<0.0001 and 2.66;p=0.0004; age 26–54: 1.91;p=0.011 and 2.30;p<0.0001; age 55+: 3.01;p=0.019 and 2.25;p=0.037 respectively). Manufacturing was among the highest risk industries for the two younger groups (18–25: 2.62;p=0.0006; 26–54: 1.59;p<0.0001). In addition, there was a higher risk associated with being in Healthcare/social assistance for workers aged 18–25 (2.71;p=0.001), and Transportation/communication/other public utilities for workers aged 55+ (2.55;p=0.002).

Risk factors for workplace injury (i.e. male gender, non-Hispanic white race/ethnicity) were similar for the two youngest groups, and echo those in the overall population. However, for workers 55+, only Industry was associated with injury risk. Agriculture/forestry/fisheries and Construction were consistently among the highest risk industries across all age groups, and risk of injury was increased in Manufacturing for workers in the two younger groups. In addition, older workers in Transportation/communication/other public utilities and younger workers in Healthcare/social assistance sectors were at increased injury risk. These results are consistent with previous studies that found an increased risk of fatal workplace injury in Agriculture/forestry/fishing and Construction [Purschwitz and Field 1990, Tiesman, et al. 2011, Bell, et al. 1990]. We showed that workers in these industries are generally at the highest risk of workplace injuries across all age groups even after adjustment for social class factors including education and poverty status. Transportation was also previously reported as having increased fatal injury risk [Tiesman, et al. 2011, Bell, et al. 1990], and we found it to be an especially high-risk industry for older workers.

Much of the occupational injury research so far has focused on injuries in specific occupations (e.g. construction workers) or a subset of injuries (e.g. fatal, brain), and virtually no recent studies exist comparing injury risk across industries. Several studies comparing age-specific injury risks have been done, however reasons for differences in risk across age groups are still not clear. Explanations offered include: greater lengths of employment and greater experience among older workers [Chau, et al. 2010], ability to withstand higher physical demand among younger workers [Chau, et al. 2009], and particular kinds of injuries that different age groups are prone to [Kemmlert and Lundholm 2001, Laflamme 1997, Landy, et al. 2011]. Workers of different ages also differ in patterns of employment within industries. While age-targeted interventions could be implemented within high-risk industries, it is important to understand age-specific exposures within those industries that put workers at higher risk.

Across the U.S. workforce, opportunities exist for age-targeted injury prevention interventions. Given that the risk of work-related injury for workers in the Agriculture/forestry/fisheries and Construction sectors was among the highest for all age groups, development of effective workplace injury prevention strategies is essential for these sectors. There is also a need for better injury prevention programs targeting specific age groups at risk in Healthcare/social assistance and Transportation/communication/other public utilities sectors.