Reference | Study aim and research design | Study population | Definition of body weight* | Definition of occupational injury | Association between body weight and obesity† |
Heineman et al12 | To identify risk factors for fireground injuries among professional firefighters; case–control study | 1200 fire fighters in the Boston area | Self-reported height and weight from a telephone interview; Quetlet’s index: weight (kg)/height (cm2) | Lost work time injury (due to burns and falls) between 1/1/86 and 31/12/86 | OR for BMI and fireground fall-related injury = 3.3 (0.5 to 22.8) when matched on position, size, and type of fire‡ |
Gauchard et al13 | To determine individual employee characteristics associated with workplace injuries due to imbalance; case–control study | 427 male employees employed for 3 or more years by the French National Society of Railway | Weight and height measured at physical exams; BMI (only assessed risk for BMI ⩾30 kg/m2) | At least one non-fatal occupational accident with sick leave between 1/3/99 and 29/2/00. Three categories of injuries: slip, trip, collision with a moving vehicle, or bad landing on the floor (when getting out of a vehicle) | OR for BMI ⩾30 and: slips (1.13 (0.53 to 2.44)); trips (1.33 (0.76 to 2.37)); bad landing (1.10 (0.42 to 2.89)). Adjusted OR for BMI ⩾30 and sick leave of ⩾8 days −2.07 (1.03 to 4.16), p<0.05 |
Chau et al14 | To assess the relationships of job, age, and life conditions with the causes and severity of occupational injuries; case–control study | 880 male construction workers | Physician measured height and weight; BMI dichotomized into ⩽25 and ⩾26 | At least one occupational injury with subsequent sick leave between 1/1/95 and 31/12/96, and seen by an occupational physician; in workers with more than one injury, only the last injury was retained | Bivariate association between BMI and injury, p<0.10, and between BMI and hospitalization, p<0.10; difference in distribution of BMI for falls to the same level and falls to the lower level both had p = 0.06; OR for BMI ⩾26 and falls on same level = 1.85 (1.15 to 3.00), p<0.01, and falls to a lower level = 1.68 (1.19 to 2.37), p<0.01; stepwise forward procedure OR for BMI ⩾26 and falls on same level = 2.04 (1.30 to 3.21), p<0.05, and falls to a lower level = 1.66 (1.20 to 2.29), p<0.05; OR for BMI ⩾26 and sick leave >60 days = 1.32 (0.96 to 1.82)‡ |
Myers et al15 | To examine the effects of anthropometric, ergonomic, and psychosocial factors on the risk of low back injury; case–control study | 200 injured case patients and 400 controls of Baltimore City Municipal workers: education, public works, recreation and parks, transportation | Height and weight measured by interviewers within 10 days of an injury; BMI | Workers with incident reported back injury 1/3/90 – 1/4/91 who had been assigned restricted activity or lost work time | Mean BMI (27.9 and 27.0) different between cases and controls (p<0.05); OR for case and 1st control: 1.47 (0.99 to 2.19); OR for case and 2nd control: 1.67 (1.11 to 2.52); OR for case and both controls: 1.54 (1.09 to 2.16) |
Bigos et al16 | To evaluate the impact of low back injuries in manufacturing employees; cross-sectional study | 31 200 hourly employees at the Boeing Company | Height and weight from claims | 4645 injury claims (including 900 back injury) filed between 1/7/79 and 28/2/81 | No significant differences in the height and weight, by sex, of back versus non-back injury claimants and of high- versus low-cost back injury claimants; data not shown |
Kraus et al17 | To determine the effect of back belt use on the incidence of back injury in home attendants; cluster-randomized trial | 9 home attendant agencies employing 12 772 home attendants | Height and weight obtained at baseline (May–August 1997); BMI | Number of injury claims filed by each person over a 28-month period, from 1/6/97 to 30/9/99 | Crude rate ratio for risk of injury and: underweight/normal (1.03 (0.57 to 1.86)); marginally overweight (1.39 (0.55 to 3.52)); overweight (1.29 (0.74 to 2.25)); severely overweight (1.41 (0.74 to 2.66)). Adjusted rate ratio for increasing BMI and injury (1.21 (0.98 to 1.50)). Adjusted rate ratio for risk of injury and: underweight/normal (1.22 (0.66 to 2.26)); marginally overweight/overweight (1.36 (0.55 to 1.06)); severely overweight (1.22 (0.73 to 2.02)) |
Ryden et al18 | To examine the relationship between low back injury and individual and workplace risk factors. Case–control study | 84 cases of low back injuries and 168 controls of hospital and health center employees | Medical records. Used the 1983 Metropolitan Height and Weight Table to classify employees as normal, overweight, or obese. Up to 30 lb = overweight for height (overweight); more than 30 lb = obese | Low back injury occurring during the work day, regardless of time lost or workers’ compensation claim | Two-sample t test found no difference between cases and controls in terms of mean height and weight (p<0.4). Risk of injury and: underweight (1.47 (0.70 to 3.10)); normal weight (0.93 (0.30 to 2.82)); overweight (0.90 (0.25 to 3.19)); overweight/obese (0.91 (0.27 to 3.05)) |
Brown and Thomas19 | To evaluate a number of risk factors for back injury among medical center employees. Descriptive study | 233 medical centre employees | BMI, obtained from medical records. Height and weight taken when a claim was reported | Workers compensation claims that resulted in lost work time | 71% of injured workers had a BMI>25; of these, 31% were obese and 11% were extremely obese‡. 67% of workers with a strain injury had a BMI>25‡. Association between increasing BMI and loss of productivity cost (Pearson χ2 = 24.13; df = 9, p = 0.004). Association between increasing BMI and injury site (Pearson χ2 = 36.82; df = 9, p = 0.098) |
Wohl et al20 | To assess the influence of family-related factors outside of work on a woman’s risk of injury. Case–control study | 1400 female manufacturing workers at a large aircraft manufacturing company, 1/1/89–31/12/89. 1400/4200 (33%) female manufacturing workers | Height and weight from company health records. BMI | Any woman who reported an acute traumatic work injury during calendar year 1989 | Crude odds ratio for injury and: underweight (0.9 (0.3 to 1.7)); normal (referent); overweight (1.6 (1.0 to 2.6)); obese (1.5 (0.9 to 2.6)).χ2 test for trend, p = 0.03. Adjusted odds ratio for injury and:‡ underweight (0.8 (0.4 to 2.03)); normal (referent); overweight (1.5 (0.9 to 2.6)); obese (1.7 (1.0 to 3.0)) |
Low et al21 | To assess the incidence, diversity, and personal risk factors for farm injuries. Cross-sectional study | 919 surveyed farms in New South Wales | Self-reported height and weight from a telephone interview. BMI | Injury that resulted in suspension of usual farm activities for 1 day, restriction for 5 days, or professional medical care | BMI and injury parameter estimate (on the logit scale) = 0.189, SE = 0.0615.‡ BMI by sleep interaction significant with injury‡ |
Bhattacherjee et al22 | To assess the relationship of individual level risk factors on occupational injuries. Population based cross- sectional study | 2562 employed individuals randomly selected from the population | Self-reported height and weight from a survey administered in 1996. BMI, three groups: ⩽19, 20–24, ⩾25 kg/m2 | Presence of at least one occupational injury in the 2-year period before the survey (1994–96). Occupational injury had to result in sick leave from work and lead to compensation | Distribution of incidence of injuries by BMI: ⩽19 = 2.6%; 20–24 = 4.3%; ⩾25 = 5.4%; p<0.01. Interaction of BMI and injury: partial likelihood ratio χ2 = – 2.7, df = 2, not statistically significant‡ |
Froom et al23 | To evaluate body weight as an independent risk factor for injuries in industrial workers. Case–control study | 4306 men, 21 industrial plants in Israel: electronics, textiles, and furniture, food, and tire factories, and iron production plants | Weight and height measured at physical exams that occurred 1985–1987. BMI, Categorized as: <22.8, 22.8–25.3, 25.4–27.9, >27.9 | On-site injuries with at least one day’s loss of work 1986–1987. Injury categories: falls, struck by moving objects, caught in machinery, road accidents, and other. 870 injuries (707/3801 male workers) | OR for BMI and single injury versus no injury = 1.01 (0.92 to 1.09), p = 0.89. OR for BMI and two or more injuries versus no injuries = 1.25 (1.03 to 1.5), p = 0.02 |
*BMI, body mass index.
†OR, odds ratio; estimates reflect OR for BMI and injury (lower bound CI, upper bound CI).
‡No p value presented.