Physical work exposure matrix for use in the UK Biobank.

BACKGROUND: UK Biobank (UKB) is a large prospective cohort capturing numerous health outcomes, but limited occupational information (job title, self-reported manual work and occupational walking/standing). AIMS: To create and evaluate validity of a linkage between UKB and a job exposure matrix for physical work exposures based on the US Occupational Information Network (O*NET) database. METHODS: Job titles and UK Standard Occupational Classification (SOC) codes were collected during UKB baseline assessment visits. Using existing crosswalks, UK SOC codes were mapped to US SOC codes allowing linkage to O*NET variables capturing numerous dimensions of physical work. Job titles with the highest O*NET scores were assessed to evaluate face validity. Spearman's correlation coefficients were calculated to compare O*NET scores to self-reported UKB measures. RESULTS: Among 324 114 participants reporting job titles, 323 936 were linked to O*NET. Expected relationships between scores and self-reported measures were observed. For static strength (0-7 scale), the median O*NET score was 1.0 (e.g. audiologists), with a highest score of 4.88 for stone masons and a positive correlation with self-reported heavy manual work (Spearman's coefficient = 0.50). For time spent standing (1-5 scale), the median O*NET score was 2.72 with a highest score of 5 for cooks and a positive correlation with self-reported occupational walking/standing (Spearman's coefficient = 0.56). CONCLUSIONS: While most jobs were not physically demanding, a wide range of physical work values were assigned to a diverse set of jobs. This novel linkage of a job exposure matrix to UKB provides a potentially valuable tool for understanding relationships between occupational exposures and disease.

Influence of work organization and work environment on missed work, productivity, and use of pain medications among construction apprentices.

BACKGROUND: Construction is among the most dangerous industries. In addition to traditional hazards for workplace injury and illness, other threats to health and well-being may occur from work organization and work environment factors, including irregular employment, long commutes, long work hours, and employer policies regarding health and safety. These nontraditional hazards may affect work and health outcomes directly, or through effects on health behaviors. The cumulative impacts of both traditional and nontraditional hazards on health-related outcomes among construction workers are largely unknown. METHODS: We conducted a survey among apprentice construction workers to identify relationships between work organization and environmental factors with five outcomes of economic relevance to employers: missed work due to work-related injury, missed work due to any pain or injury, self-reported workability, health-related productivity, and use of prescription medications for pain. RESULTS: A total of 963 surveys were completed (response rate 90%) in this young (mean age 28) working cohort. Multivariate Poisson regression models found associations between the outcomes of interest and multiple work factors, including job strain, safety behaviors of coworkers, and mandatory overtime. Univariate analysis showed additional associations, including precarious work, and supervisor support for safety. CONCLUSIONS: Findings from this cross-sectional study suggest that work organization and environment factors influence health and work outcomes among young construction trade workers. Future work with longitudinal data will examine the hypothesized paths between work factors, health behaviors, health outcomes, and work outcomes.

Carpal tunnel syndrome and computer exposure at work in two large complementary cohorts.

OBJECTIVES: The boom in computer use and concurrent high rates in musculoskeletal complaints and carpal tunnel syndrome (CTS) among users have led to a controversy about a possible link. Most studies have used cross-sectional designs and shown no association. The present study used longitudinal data from two large complementary cohorts to evaluate a possible relationship between CTS and the performance of computer work. SETTINGS AND PARTICIPANTS: The Cosali cohort is a representative sample of a French working population that evaluated CTS using standardised clinical examinations and assessed self-reported computer use. The PrediCTS cohort study enrolled newly hired clerical, service and construction workers in several industries in the USA, evaluated CTS using symptoms and nerve conduction studies (NCS), and estimated exposures to computer work using a job exposure matrix. PRIMARY AND SECONDARY OUTCOME MEASURES: During a follow-up of 3-5 years, the association between new cases of CTS and computer work was calculated using logistic regression models adjusting for sex, age, obesity and relevant associated disorders. RESULTS: In the Cosali study, 1551 workers (41.8%) completed follow-up physical examinations; 36 (2.3%) participants were diagnosed with CTS. In the PrediCTS study, 711 workers (64.2%) completed follow-up evaluations, whereas 31 (4.3%) had new cases of CTS. The adjusted OR for the group with the highest exposure to computer use was 0.39 (0.17; 0.89) in the Cosali cohort and 0.16 (0.05; 0.59) in the PrediCTS cohort. CONCLUSIONS: Data from two large cohorts in two different countries showed no association between computer work and new cases of CTS among workers in diverse jobs with varying job exposures. CTS is far more common among workers in non-computer related jobs; prevention efforts and work-related compensation programmes should focus on workers performing forceful hand exertion.

Development of targeted messages to promote smoking cessation among construction trade workers.

Blue-collar workers, particularly those in the construction trades, are more likely to smoke and have less success in quitting when compared with white-collar workers. Little is known about health communication strategies that might influence this priority population. This article describes our formative work to develop targeted messages to increase participation in an existing smoking cessation program among construction workers. Using an iterative and sequential mixed-methods approach, we explored the culture, health attitudes and smoking behaviors of unionized construction workers. We used focus group and survey data to inform message development, and applied audience segmentation methods to identify potential subgroups. Among 144 current smokers, 65% reported wanting to quit smoking in the next 6 months and only 15% had heard of a union-sponsored smoking cessation program, despite widespread advertising. We tested 12 message concepts and 26 images with the target audience to evaluate perceived relevance and effectiveness. Participants responded most favorably to messages and images that emphasized family and work, although responses varied by audience segments based on age and parental status. This study is an important step towards integrating the culture of a high-risk group into targeted messages to increase participation in smoking cessation activities.

Neurologist care in Parkinson disease: a utilization, outcomes, and survival study.

OBJECTIVE: To investigate the utilization of neurologist providers in the treatment of patients with Parkinson disease (PD) in the United States and determine whether neurologist treatment is associated with improved clinical outcomes. METHODS: This was a retrospective observational cohort study of Medicare beneficiaries with PD in the year 2002. Multilevel logistic regression was used to determine which patient characteristics predicted neurologist care between 2002 and 2005 and compare the age, race, sex, and comorbidity-adjusted annual risk of skilled nursing facility placement and hip fracture between neurologist- and primary care physician-treated patients with PD. Cox proportional hazards models were used to determine the adjusted 6-year risk of death using incident PD cases, stratified by physician specialty. RESULTS: More than 138,000 incident PD cases were identified. Only 58% of patients with PD received neurologist care between 2002 and 2005. Race and sex were significant demographic predictors of neurologist treatment: women (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.76-0.80) and nonwhites (OR 0.83, 95% CI 0.79-0.87) were less likely to be treated by a neurologist. Neurologist-treated patients were less likely to be placed in a skilled nursing facility (OR 0.79, 95% CI 0.77-0.82) and had a lower risk of hip fracture (OR 0.86, 95% CI 0.80-0.92) in logistic regression models that included demographic, clinical, and socioeconomic covariates. Neurologist-treated patients also had a lower adjusted likelihood of death (hazard ratio 0.78, 95% CI 0.77-0.79). CONCLUSIONS: Women and minorities with PD obtain specialist care less often than white men. Neurologist care of patients with PD may be associated with improved selected clinical outcomes and greater survival.

Evaluation of anti-vibration interventions for the hand during sheet metal assembly work.

OBJECTIVE: Occupational use of vibrating hand tools contributes to the development of upper extremity disorders. While several types of vibration damping materials are commercially available, reductions in vibration exposure are usually tested in the laboratory rather than in actual work environments. This study evaluated reductions in hand vibration with different vibration damping interventions under actual work conditions. METHODS: Three experienced sheet metal assemblers at a manufacturing facility installed sheet metal fasteners with a pneumatic tool using no vibration damping (bare hand) and each of six anti-vibration interventions (five different gloves and a viscoelastic tool wrap). Vibration was measured with tri-axial accelerometers on the tool and the back of the hand. RESULTS: Unweighted mean vibration measured at the hand showed reduced vibration (p<0.001) for all six interventions (range = 3.07-5.56 m/s(2)) compared to the bare hand condition (12.91 m/s(2)). CONCLUSIONS: All of the interventions were effective at reducing vibration at the hand during testing under usual work conditions. Field testing beyond laboratory-based testing accounts for the influences of worker, tools, and materials on vibration transmission to the body from specific work operations.

Variability and misclassification of worker estimated hand force.

Ergonomic studies often use worker estimated hand force reproduced on a dynamometer to quantify force exposures but this method has not been well-studied in real work settings. This study evaluated the validity of worker estimates of hand force in a field study and determined the misclassification of worker estimated hand force exposures compared to directly measured forces. Eight experienced sheet metal assemblers completed »-inch diameter fastener installations using 6 different pneumatic tools. Grip forces were recorded by a pressure mat and were compared to worker estimated forces demonstrated on a dynamometer. Directly measured and worker estimated readings showed moderate correlations (0.53-0.67) for four installation tools and fair to moderate for two tools. The coefficient for variation of force estimates was 65% within repeated subject trials and 78% between averaged subject trials but 69% between subject trials during actual tool installations. Misclassification of worker estimated exposures varied by two cut-points: 29% using 4.0 kg and 49% using 6.0 kg. The force match procedure may provide adequate differentiation of high and low exposures in some settings, but is likely to result in substantial misclassification in other settings.

Diagnostic strategies using physical examination are minimally useful in defining carpal tunnel syndrome in population-based research studies.

OBJECTIVE: We evaluated the utility of physical examination manoeuvres in the prediction of carpal tunnel syndrome (CTS) in a population-based research study. METHODS: We studied a cohort of 1108 newly employed workers in several industries. Each worker completed a symptom questionnaire, a structured physical examination and nerve conduction study. For each hand, our CTS case definition required both median nerve conduction abnormality and symptoms classified as "classic" or "probable" on a hand diagram. We calculated the positive predictive values and likelihood ratios for physical examination manoeuvres in subjects with and without symptoms. RESULTS: The prevalence of CTS in our cohort was 1.2% for the right hand and 1.0% for the left hand. The likelihood ratios of a positive test for physical provocative tests ranged from 2.0 to 3.3, and those of a negative test from 0.3 to 0.9. The post-test probability of positive testing was <50% for all strategies tested. CONCLUSION: Our study found that physical examination, alone or in combination with symptoms, was not predictive of CTS in a working population. We suggest using specific symptoms as a first-level screening tool, and nerve conduction study as a confirmatory test, as a case definition strategy in research settings.

Do workers with self-reported symptoms have an elevated risk of developing upper extremity musculoskeletal disorders three years later?

OBJECTIVES: Few prospective studies have evaluated outcomes of workers with self-reported symptoms of upper extremity musculoskeletal disorders (UEMSD). The objective was to study the three-year outcomes of workers with self-reported symptoms, with or without a positive physical examination. METHODS: In 1993-4, 598 subjects highly exposed to repetitive work filled out a Nordic-style questionnaire. They underwent a standardised physical examination at that time and again in 1996-7 by the same occupational physician. The three-year outcomes (based on physical examination) of workers with a self-administered questionnaire positive at baseline for UEMSD, with or without a positive physical examination, were studied. RESULTS: The three-year incidence rate was 44.1%; one third of these incident cases had self-reported symptoms in 1993-4. Workers with a positive questionnaire had a significantly higher risk of UEMSD at physical examination three years later (80.1% UEMSD cases with positive questionnaires n = 354, vs 44.2% cases without positive questionnaires n = 69, p<0.001). Moreover, workers with positive questionnaires but without UEMSD diagnosed in 1993-4 (n = 177) also had a significantly higher risk of UEMSD at physical examination three years later (60.5% cases with positive questionnaires n = 26, vs 38.8% cases without positive questionnaires n = 52, p = 0.01). Results were similar when gender and age were taken into account. CONCLUSION: Workers highly exposed to repetitive movements have a high risk of developing UEMSD and should be followed closely in surveillance programmes. Workers with self-reported symptoms without UEMSD diagnosed in physical examination represented only one third of new cases three years later. However, their risk of developing UEMSD was significantly increased, compared with those without symptoms.

Why are manual workers at high risk of upper limb disorders? The role of physical work factors in a random sample of workers in France (the Pays de la Loire study).

OBJECTIVE: To investigate the reasons for the excess risk of upper limb musculoskeletal disorders among manual workers compared with other workers in a random sample of 2656 French men and women (20-59 years old) participating in a study on the prevalence of work related upper limb disorders conducted by France's National Institute of Health Surveillance. METHODS: Prevalence ratios (PR) of physician-diagnosed musculoskeletal disorders of the shoulder, elbow, wrist, and hand (any of six leading disorders, rotator cuff syndrome, carpal tunnel syndrome) in manual versus non-manual workers were calculated using Cox regression models with a constant time of follow up and robust variance. RESULTS: 11.3% of men and 15.1% of women were diagnosed with an upper limb disorder. The risk was especially high in manual workers (PRs: 1.40 to 2.10). Physical work factors accounted for over 50% of occupational disparities overall, 62% (men) to 67% (women) for rotator cuff syndrome, and 96% (women) for carpal tunnel syndrome. The authors calculated that under lower levels of physical work exposures, up to 31% of cases among manual workers could have been prevented. CONCLUSIONS: In working men and women, upper limb musculoskeletal disorders are frequent. Physical work exposures, such as repetitive and forceful movements, are an important source of risk and in particular account for a large proportion of excess morbidity among manual workers.

Prevalence of parkinsonism and relationship to exposure in a large sample of Alabama welders.

OBJECTIVE: To estimate the prevalence of parkinsonism in welders in Alabama and to compare this prevalence with that in a general population sample. METHODS: The authors screened 1,423 welders from Alabama who were referred for medical-legal evaluation for Parkinson disease (PD). Standardized videotaped assessments using the Unified Parkinson's Disease Rating Scale motor subsection 3 (UPDRS3) were obtained. Patients provided information regarding exposure to welding fumes and job titles. Job titles were matched with Department of Labor Standard Occupational Codes (SOCs). Diagnoses were assigned based on quantitative criteria for the diagnosis of PD using two thresholds for diagnosis. With use of the number of active welders in this screening with parkinsonism as the numerator and the age-adjusted number of welders in each SOC as the denominator, the prevalence of parkinsonism in Alabama welders was estimated using conservative assumptions and compared with general population data from Copiah County, MS. RESULTS: With use of conservative and liberal case definitions of parkinsonism, the estimated prevalence of parkinsonism among active male welders age 40 to 69 statewide was 977 to 1,336 cases/100,000 population. The prevalence of parkinsonism was higher among welders vs age-standardized data for the general population (prevalence ratio = 10.19, 95% CI 4.43 to 23.43). CONCLUSION: The estimated prevalence of parkinsonism was higher within a sample of male Alabama welders vs the general population of male residents of Copiah County, MS.

An evaluation of a "best practices" musculoskeletal injury prevention program in nursing homes.

OBJECTIVE: To conduct an intervention trial of a "best practices" musculoskeletal injury prevention program designed to safely lift physically dependent nursing home residents. DESIGN: A pre-post intervention trial and cost benefit analysis at six nursing homes from January 1995 through December 2000. The intervention was established in January 1998 and injury rates, injury related costs and benefits, and severity are compared for 36 months pre-intervention and 36 months post-intervention. PARTICIPANTS: A dynamic cohort of all nursing staff (n = 1728) in six nursing homes during a six year study period. INTERVENTION: "Best practices" musculoskeletal injury prevention program consisting of mechanical lifts and repositioning aids, a zero lift policy, and employee training on lift usage. MAIN OUTCOME MEASURES: Injury incidence rates, workers' compensation costs, lost work day injury rates, restricted work day rates, and resident assaults on caregivers, annually from January 1995 through December 2000. RESULTS: There was a significant reduction in resident handling injury incidence, workers' compensation costs, and lost workday injuries after the intervention. Adjusted rate ratios were 0.39 (95% confidence interval (CI) 0.29 to 0.55) for workers' compensation claims, 0.54 (95% CI 0.40 to 0.73) for Occupational Safety and Health Administration (OSHA) 200 logs, and 0.65 (95% CI 0.50 to 0.86) for first reports of employee injury. The initial investment of $158 556 for lifting equipment and worker training was recovered in less than three years based on post-intervention savings of $55 000 annually in workers' compensation costs. The rate of post-intervention assaults on caregivers during resident transfers was down 72%, 50%, and 30% based on workers' compensation, OSHA, and first reports of injury data, respectively. CONCLUSIONS: The "best practices" prevention program significantly reduced injuries for full time and part time nurses in all age groups, all lengths of experience in all study sites.

Use of mechanical patient lifts decreased musculoskeletal symptoms and injuries among health care workers.

OBJECTIVE: To evaluate the effectiveness of mechanical patient lifts in reducing musculoskeletal symptoms, injuries, lost workday injuries, and workers' compensation costs in workers at a community hospital. DESIGN: Pre-post intervention study. SETTING: Three nursing units of a small community hospital. Patients or SUBJECTS: Nursing personnel. INTERVENTIONS: Mechanical patient lifts were made available and nursing staff trained in their use between August 2000 and January 2001. MAIN OUTCOME MEASURES: Workers completed symptom surveys at baseline and six months after lift training. Pre-intervention and post-intervention rates of injuries and lost workday injuries using Occupational Safety and Health Administration logs of the three study units, from the period July 1999 through March 2003 were analyzed. Injuries potentially related to lifting patients were included in the analyses. Using workers' compensation data from the same time period, the compensation paid ($ per full time equivalent [FTE]) due to injuries during the pre-intervention and post-intervention period was calculated. RESULTS: Sixty one staff members were surveyed pre-intervention; 36 (59%) completed follow up surveys. Statistically significant improvements in musculoskeletal comfort (p<0.05) were reported for all body parts, including shoulders, lower back, and knees. Injury rates decreased post-intervention, with a relative risk (RR) of 0.37 (95% confidence interval (CI) 0.16 to 0.88); decreased injury rates persisted after adjustment for temporal trends in injury rates on non-intervention units of the study hospital (RR = 0.50, 95% CI 0.20 to 1.26). Adjusted lost day injury rates also decreased (RR = 0.35, 95% CI 0.10 to 1.16). Annual workers' compensation costs averaged $484 per FTE pre-intervention and $151 per FTE post-intervention. CONCLUSION: Reductions were observed in injury rates, lost workday injury rates, workers' compensation costs, and musculoskeletal symptoms after deployment of mechanical patient lifts. Strengths of this study include the community hospital setting and the inclusion of a variety of different outcomes. Limitations include the pre-post study design and the small sample size.

Reduction in injury rates in nursing personnel through introduction of mechanical lifts in the workplace.

BACKGROUND: Health care workers incur frequent injuries resulting from patient transfer and handling tasks. Few studies have evaluated the effectiveness of mechanical lifts in preventing injuries and time loss due to these injuries. METHODS: We examined injury and lost workday rates before and after the introduction of mechanical lifts in acute care hospitals and long-term care (LTC) facilities, and surveyed workers regarding lift use. RESULTS: The post-intervention period showed decreased rates of musculoskeletal injuries (RR = 0.82, 95% CI: 0.68-1.00), lost workday injuries (RR = 0.56, 95% CI: 0.41-0.78), and total lost days due to injury (RR = 0.42). Larger reductions were seen in LTC facilities than in hospitals. Self-reported frequency of lift use by registered nurses and by nursing aides were higher in the LTC facilities than in acute care hospitals. Observed reductions in injury and lost day injury rates were greater on nursing units that reported greater use of the lifts. CONCLUSIONS: Implementation of patient lifts can be effective in reducing occupational musculoskeletal injuries to nursing personnel in both LTC and acute care settings. Strategies to facilitate greater use of mechanical lifting devices should be explored, as further reductions in injuries may be possible with increased use.

Improved compliance with universal precautions in the operating room following an educational intervention.

Observation of surgical personnel in four specialties (cardiothoracic, general, gynecologic, and orthopedic) in the operating room was performed prior to implementation of an educational intervention designed to improve compliance with Universal Precautions and at 1- and 2-years post-intervention. Use of protective eyewear and double gloving increased following the intervention, whereas the incidence of documented blood and body fluid exposures decreased.

Natural history of asymptomatic rotator cuff tears: a longitudinal analysis of asymptomatic tears detected sonographically.

The purpose of this study was to examine longitudinally the natural history of asymptomatic rotator cuff tears over a 5-year period and to assess the risk for development of symptoms and tear progression. Since 1985 through the present, bilateral sonograms were done on all patients. A review of consecutive sonograms done from 1989 to 1994 revealed 58 potential patients with unilateral symptoms who had contralateral asymptomatic rotator cuff tears. Of these 58 patients, 45 (22 men, 23 women) responded to a comprehensive questionnaire and 23 additionally returned for examination and repeat sonographic evaluation. The questionnaire was based on the American Shoulder and Elbow Surgeons score and included several outcome-based questions. A physical examination was performed in a standardized fashion along American Shoulder and Elbow Surgeons guidelines. Repeat high-resolution sonograms were performed by a single experienced radiologist. Primary and repeat sonograms were then reassessed for tear size and location by two independent experienced radiologists blinded to the clinical data results. Twenty-three (51%) of the previously asymptomatic patients became symptomatic over a mean of 2.8 years. The average Activities of Daily Living score for those remaining asymptomatic was 28.5 of 30 and for those becoming newly symptomatic, 22.9 of 30 (P <.5). The mean visual analog pain score (1 = no pain) for those remaining asymptomatic was 1.1 and for the newly symptomatic patients, 4.0. Of the 23 patients who returned for ultrasound, 9 were asymptomatic and 14 symptomatic. Only 2 of the 9 patients remaining asymptomatic had progression of their tears. Overall, 9 of 23 patients had tear progression. No patient had a decrease in the size of the tear. Our results demonstrate that symptoms can develop in patients with previously asymptomatic rotator cuff tears when seen in the context of a contralateral symptomatic tear. Development of symptoms was associated with a significant increase in pain and decrease in the ability to perform activities of daily living (P <.05). There appears to be a risk for tear size progression over time.

Retrograde versus antegrade nailing of femoral shaft fractures.

OBJECTIVES: To compare union rates and complications of retrograde intramedullary nailing of femoral shaft fractures with those of antegrade intramedullary nailing. DESIGN: Retrospective. SETTING: Level I trauma center. PATIENTS: Two hundred eighty-three consecutive adult patients with 293 fractures of the femoral shaft who underwent stabilization with antegrade or retrograde inserted femoral nails were studied. There were 140 retrograde nails and 153 antegrade nails. Twelve fractures in twelve patients were excluded (three in patients who died early in the postoperative period, three in patients because of early amputation, four in patients who were paraplegic, and two in patients who fractured through abnormal bone owing to metastatic carcinoma), leaving 134 fractures treated with retrograde nails and 147 treated with antegrade nails. One hundred four femurs treated with retrograde nails (Group R) and ninety-four femurs treated with antegrade nails (Group A) had sufficient follow-up and served as the two study groups. The average clinical follow-up was twenty-three months (range 6 to 66 months) for Group R and twenty-three months (range 5 to 64 months) for Group A. Both groups were comparable with regard to age, gender, number of open fractures, degree of comminution, mode of interlocking (i.e., static or dynamic), and nail diameter (p > 0.05). INTERVENTION: Retrograde intramedullary nails were inserted through the intercondylar notch of the knee, and antegrade nails were inserted through the pirformis fossa using standard techniques. MAIN OUTCOME MEASURES: Union, delayed union, nonunion, malunion, and complication rates. RESULTS: After the index procedure there were no significant differences in healing or incidence of malunion between Group R and Group A (p > 0.05). Healing after the index procedure occurred in ninety-one (88 percent) of the femurs in Group R and in eighty-four (89 percent) of the femurs in Group A. In Group R, there were seven delayed unions (7 percent) and six nonunions (6 percent). In Group A, there were four delayed unions (4 percent) and six nonunions (6 percent). Healing ultimately occurred in 100 (96 percent) femurs from Group R and in ninety-three (99 percent) femurs from Group A. In Group R, there were eleven malunions (11 percent), and in Group A, there were twelve malunions (13 percent). When patients with ipsilateral knee injuries were excluded, the incidence of knee pain was significantly greater for Group R patients (36 percent) than for Group A patients (9 percent) (p < 0.001). When patients with ipsilateral hip injuries were excluded, the incidence of hip pain was significantly greater for Group A patients (10 percent) than for Group R patients (4 percent) (p < 0.05). CONCLUSIONS: Retrograde and antegrade nailing techniques provided similar results in union and malunion rates. There were more complications related to the knee after retrograde nailing and more complications related to the hip after antegrade nailing.

Angular malalignment after intramedullary nailing of femoral shaft fractures.

OBJECTIVES: To determine factors associated with angular malalignment of femoral shaft fractures treated with intramedullary nails and to determine differences in the incidence of angular malalignment based on fracture location, fracture comminution, and method of treatment (i.e., antegrade or retrograde). DESIGN: Retrospective. SETTING: Level I trauma center. PATIENTS: Three hundred sixty patients with 374 femoral shaft fractures were identified from a prospectively obtained orthopaedic trauma database. Complete sets of immediate postoperative anteroposterior and lateral radiographs were available for 355 (95 percent) of the 374 fractures. INTERVENTION: Patients were treated with antegrade (183 cases) or retrograde (174 cases) intramedullary femoral nailing. MAIN OUTCOME MEASURE: Goniometric measurements were made on all immediate postoperative radiographs to determine the coronal plane and sagittal plane angular alignments. A multiple linear regression statistical analysis was used to determine factors associated with increasing angular malalignment. The incidence of malalignment was determined using more than 5 degrees of deformity in any plane as the definition of malalignment. RESULTS: Proximal fracture location, distal fracture location, and unstable fracture pattern were associated with increasing fracture angulation (p < 0.001). Fracture location in the middle third, stable fracture pattern, method of treatment (i.e., antegrade or retrograde), and nail diameter were not associated with increasing fracture angulation (p > 0.05). The incidence of malalignment was 9 percent for the entire group of patients, 30 percent when the fracture was of the proximal third of the femoral shaft, 2 percent when the fracture was of the middle third, and 10 percent when the fracture was of the distal third. The incidence of malreduction was 7 percent for patients with stable fracture patterns and 12 percent for those with unstable fracture patterns. CONCLUSIONS: Patients with fractures of the proximal third of the femoral shaft treated with intramedullary nails are at highest risk for malalignment. Proximal fracture location, distal fracture location, and unstable fracture pattern are associated with increasing fracture angulation.