Frequent Exertion and Frequent Standing at Work, by Industry and Occupation Group — United States, 2015

Repeated exposure to occupational ergonomic hazards, such as frequent exertion (repetitive bending or twisting) and frequent standing, can lead to injuries, most commonly musculoskeletal disorders (1). Work-related musculoskeletal disorders have been estimated to cost the United States approximately $2.6 billion in annual direct and indirect costs (2). A recent literature review provided evidence that prolonged standing at work also leads to adverse health outcomes, such as back pain, physical fatigue, and muscle pain (3). To determine which industry and occupation groups currently have the highest prevalence rates of frequent exertion at work and frequent standing at work, CDC analyzed data from the 2015 National Health Interview Survey (NHIS) Occupational Health Supplement (OHS) regarding currently employed adults in the United States. By industry, the highest prevalence of both frequent exertion and frequent standing at work was among those in the agriculture, forestry, fishing, and hunting industry group (70.9%); by occupation, the highest prevalence was among those in the construction and extraction occupation group (76.9%). Large differences among industry and occupation groups were found with regard to these ergonomic hazards, suggesting a need for targeted interventions designed to reduce workplace exposure.

NHIS is an annual, in-person, household interview survey of noninstitutionalized, U.S. civilian residents that has been continuously conducted since 1957 with the main purpose of monitoring the health of the U.S. population through assessment of a range of health topics and demographic characteristics.* The NHIS questionnaire contains a set of core questions with Household, Family, Sample Adult, and Sample Child components, which have remained relatively unchanged from 1997 through 2017. In addition, NHIS has sets of questions, known as Supplements, which vary each year depending on new public health data needs. In 2015, CDC’s National Institute for Occupational Safety and Health (NIOSH) sponsored an OHS to collect information on work-related health conditions as well as psychological and physical occupational exposures. The OHS questions were included in the Sample Adult questionnaire, which had a final, unconditional response rate of 55.2%.^†

To determine industry and occupation, currently employed adult respondents were asked, in reference to the job they were working at during the week before the interview, “What kind of business or industry was this?” and “What kind of work were you doing?” Open-ended responses were recorded as text and subsequently coded by the U.S. Census Bureau into 4-digit codes derived from the 2012 North American Industrial Classification System (NAICS) industry groups and 2010 Standard Occupational Classification (SOC) occupation groups. To improve reliability of the statistical estimates, the detailed 4-digit industry and occupation groups were collapsed into 2-digit industry groups and occupation groups (based on the NAICS and SOC major groups^§). As part of the OHS, currently employed adults were asked two questions related to the ergonomics of their current job: “How often does your job involve repeated lifting, pushing, pulling, or bending?” and “How often does your job involve standing or walking around?” Responses to these questions were dichotomized into Often/Always and Never/Seldom/Sometimes, to indicate frequent or infrequent exertion or standing, respectively. Responses to these two ergonomics questions were also used to create one dichotomous variable capturing respondents that reported both frequent exertion at work and frequent standing at work.

Among the 36,672 adult NHIS respondents, 19,456 were currently employed and considered for analyses. After excluding 1,615 respondents who worked <20 hours per week, 187 respondents who did not provide adequate information on their hours worked in the previous week, and 190 respondents in military-specific occupations, the final analytic sample included 17,464 respondents (89.8% of the currently employed adult respondents). Sample adults who worked more than 20 hours per week were more likely to be aged <65 years, men, and hold a college degree or higher; however, there was no difference in the distribution of frequent exertion and frequent standing by number of hours worked. Unadjusted prevalence of frequent exertion at work, frequent standing at work, and both frequent exertion and frequent standing at work were calculated by the 20 major industry groups and the 22 major occupation groups. The unadjusted prevalence estimates were obtained using statistical software. All analyses were weighted, and standard errors were adjusted to account for the survey design.

Overall, 39.5% of currently employed adults who work at least 20 hours per week reported both frequent exertion and frequent standing at work (Table 1). The prevalences of frequent exertion at work or frequent standing at work, or both frequent exertion at work and frequent standing at work were highest among men, persons aged 18–29 years, Hispanics, and adults with less than a high school diploma (Table 1).

Among the 20 major industry groups, the groups with the highest prevalence of both frequent exertion and frequent standing at work were agriculture, forestry, fishing, and hunting (70.9%); construction (67.2%); and accommodation and food services (57.7%) (Table 2). These same three industry groups also had the highest prevalence rates of frequent exertion at work and frequent standing at work considered separately. The finance and insurance industry group had the lowest prevalence rates of all three exposures (Table 2). Among the 22 major occupation groups, the groups with the highest prevalence of both frequent exertion and frequent standing at work were construction and extraction (76.9%); farming, fishing, and forestry (75.5%); and building and grounds cleaning and maintenance (74.0%) (Table 3). These same three occupation groups also had the highest prevalence rates for frequent exertion at work. The food preparation and serving related occupation group (97.2%) had the highest prevalence of frequent standing at work. The computer and mathematical occupation group had the lowest prevalence rate of the combined exposures of frequent exertion and frequent standing at work (4.6%) (Table 3).

Corresponding author: Taylor M. Shockey, tshockey@cdc.gov, 513-841-4239.

¹Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, CDC; ²Division of Applied Research and Technology, National Institute for Occupational Safety and Health, CDC.

References

1. Bernard BP. Musculoskeletal disorders and workplace factors: a critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, upper extremity, and low back. DHHS (NIOSH) publication no. 97–141;1997.
2. Bhattacharya A. Costs of occupational musculoskeletal disorders (MSDs) in the United States. Int J Ind Ergon 2014;44:448–54. CrossRef
3. Waters TR, Dick RB. Evidence of health risks associated with prolonged standing at work and intervention effectiveness. Rehabil Nurs 2015;40:148–65. CrossRef PubMed
4. Tak S, Calvert GM. The estimated national burden of physical ergonomic hazards among US workers. Am J Ind Med 2011;54:395–404. CrossRef PubMed
5. Lee SJ, Tak S, Alterman T, Calvert GM. Prevalence of musculoskeletal symptoms among agricultural workers in the United States: an analysis of the National Health Interview Survey, 2004–2008. J Agromed 2014;19:268–80. CrossRef PubMed
6. Boschman JS, van der Molen HF, Sluiter JK, Frings-Dresen MH. Occupational demands and health effects for bricklayers and construction supervisors: a systematic review. Am J Ind Med 2011;54:55–77. CrossRef PubMed
7. Choi SD, Hudson L, Kangas P, Jungen B, Maple J, Bowen C. Occupational ergonomic issues in highway construction surveyed in Wisconsin, United States. Ind Health 2007;45:487–93. CrossRef PubMed
8. van Uffelen JGZ, Wong J, Chau JY, et al. Occupational sitting and health risks: a systematic review. Am J Prev Med 2010;39:379–88. CrossRef PubMed
9. Coenen P, Willenberg L, Parry S, et al. Associations of occupational standing with musculoskeletal symptoms: a systematic review with meta-analysis. Br J Sports Med 2016;0:1–9. PubMed
10. da Costa BR, Vieira ER. Risk factors for work-related musculoskeletal disorders: a systematic review of recent longitudinal studies. Am J Ind Med 2010;53:285–323. PubMed

Abbreviations: CI = confidence interval; GED = General Educational Development.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
^† Education level only shown for persons aged ≥25 years.

Abbreviation: CI = confidence interval.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
^† The Management of Companies and Enterprises industry group was removed from the results because the cell size was <10 and did not meet the National Center for Health Statistics’ standards of reliability.

Abbreviation: CI = confidence interval.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
^† Estimate has a relative standard error >30% and <50% and should be used with caution because it does not meet the National Center for Health Statistics’ standards of reliability.
^§ Estimate had a cell size <10 and was removed from the results because it did not meet the National Center for Health Statistics’ standards of reliability.