Publications

OBJECTIVE

To investigate the association between occupational risk factors and the incidence of knee disorders in a young adult population.

METHODS

Israeli recruits to the Israel Defense Forces go through a rigorous medical investigation. Study participants were classified by prior knee condition status and divided into 5 categories of prospective occupational exposure to physical activity according to their assigned military duties, and were then followed for 30 months for the development of severe knee disorders (SKD). Logistic regression analysis was used to estimate the occupational risks for incident SKD, adjusted for any previous mild or moderate disorder, body mass index, and body height at induction.

RESULTS

The study population consisted of 76,491 males. SKD developed in 615 (0.8%). Compared to administrative workers as referents, a higher risk of developing SKD was manifest among high intensity combat occupations, (odds ratios [OR] 2.15), those in moderate intensity combat occupations (OR 2.57) and maintenance (OR 1.59). Drivers did not demonstrate increased risk of knee disorders compared to referents.

CONCLUSIONS

Occupational factors during military service are associated with incident SKD, even when taking into account previous knee disorders, body mass index, and height, which also had independent effects in our study population.

Higher values of the environmental relative moldiness index (ERMI), a DNA-based method for quantifying indoor molds, have been associated with asthma in children. In this study, settled dust samples were collected from the homes of adults with asthma, rhinitis, or both conditions (n=139 homes) in Northern California. The ERMI values for these samples were compared to those from dust collected in homes from the same geographic region randomly selected as part of the 2006 American Healthy Home Survey (n=44). The median ERMI value in homes of adult with airway disease (6) was significantly greater than median ERMI value (2) in the randomly selected homes (p<0.0001). In this study in Northern California, the homes of adults with asthma had ERMI values consistent with a heavier burden of indoor mold than that measured in other homes from the same region.

Health-related quality of life (HRQL) has been assessed in various lung transplantation (LT) investigations but never analyzed systematically across multiple studies. We addressed this knowledge gap through a systematic literature review. We searched the PubMed, CINAHL and PsychInfo databases for publications from January 1, 1983 to December 31, 2011. We performed a thematic analysis of published studies of HRQL in LT. Using a comparative, consensus-based approach, we identified themes that consistently emerged from the data, classifying each study according to primary and secondary thematic categories as well as by study design. Of 749 publications initially identified, 73 remained after exclusions. Seven core themes emerged: (1) Determinants of HRQL; (2) Psychosocial factors in HRQL; (3) Pre- and posttransplant HRQL comparisons; (4) Long-term longitudinal HRQL studies; (5) HRQL effects of therapies and interventions; (6) HRQL instrument validation and methodology; (7) HRQL prediction of clinical outcomes. Overall, LT significantly and substantially improves HRQL, predominantly in domains related to physical health and functioning. The existing literature demonstrates substantial heterogeneity in methodology and approach; relatively few studies assessed HRQL longitudinally within the same persons. Opportunity for future study lies in validating existing and potential novel HRQL instruments and further elucidating the determinants of HRQL through longitudinal multidimensional investigation.

BACKGROUND

Respiratory tract-related occupational disability is common among adults of working age. We examined occupational vapors, gas, dust, or fume (VGDF) exposure as a predictor of disability, based on respiratory sickness absence among the actively employed, at an early point at which prevention may be most relevant.

METHODS

Currently employed European Community Respiratory Health Survey II participants (n = 6,988) were classified into three mutually exclusive, condition/symptom-based categories: physician-diagnosed asthma, self-reported rhinitis, and wheeze/breathlessness (n = 4,772). Logistic regression analysis estimated the odds of respiratory sickness absence (past 12 months) by VGDF exposure.

RESULTS

In the condition/symptom groups, 327 (6.9%) reported respiratory sickness absence. Exposure to VGDF was associated with increased odds of respiratory sickness absence: asthma odds ratio [OR] 2.0 (95% confidence interval [CI] 1.1-3.6), wheeze/breathlessness OR 2.2 (95% CI 1.01-4.8); rhinitis OR 1.9 (95% CI 1.02-3.4).

CONCLUSION

One in 15 currently employed with asthma, breathlessness, or rhinitis reported respiratory sickness absence. VGDF exposure doubled the odds of respiratory sickness absence, suggesting a focus for disability prevention.

BACKGROUND

Cadmium (Cd) is an important metal with both common occupational and environmental sources of exposure. Although it is likely to cause adverse respiratory effects, relevant human data are relatively sparse.

METHODS

A cross-sectional study of 133 workers in jewellery workshops using Cd under poor hygienic conditions and 54 referent jewellery sales staffs was performed. We assessed symptoms, performed spirometry, measured urinary Cd levels in all study subjects and quantified airborne total oxidant contents for 35 job areas in which the studied workforce was employed. We tested the association of symptoms with exposure relative to the unexposed referents using logistic regression analysis, and tested the association between urinary Cd levels and lung function using multiple regression analysis, adjusting for demographics, smoking and area-level airborne oxidants.

RESULTS

Exposed workers had 10 times higher urinary Cd values than referents (geometric mean 5.8 vs 0.41 µg/dl; p<0.01). Of the exposed subjects, 75% reported respiratory tract symptoms compared with 33% of the referents (OR=3.1, 95% CI 1.4 to 7.3). Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were also lower among the exposed workers than the referents (>600 ml decrement for each, p<0.001). For every 1 µg increase in urinary Cd there was a 34 ml decrement in FVC and a 39 ml decrement in FEV1 (p<0.01), taking into account other covariates including workplace airborne oxidant concentrations.

CONCLUSIONS

This cohort of heavily exposed jewellery workers experienced frequent respiratory symptoms and manifested a marked deficit in lung function, demonstrating a strong response to Cd exposure.

BACKGROUND

Although occupational exposure is a known risk factor for Chronic Obstructive Pulmonary Disease (COPD), it is difficult to identify specific occupational contributors to COPD at the individual level to guide COPD prevention or for compensation. The aim of this study was to gain an understanding of how different expert clinicians attribute likely causation in COPD.

METHODS

Ten COPD experts and nine occupational lung disease experts assigned occupational contribution ratings to fifteen hypothetical cases of COPD with varying combinations of occupational and smoking exposures. Participants rated the cause of COPD as the percentage contribution to the overall attribution of disease for smoking, occupational exposures and other causes.

RESULTS

Increasing pack-years of tobacco smoking was associated with significantly decreased proportional occupational causation ratings. Increasing weighted occupational exposure was associated with increased occupational causation ratings by 0.28% per unit change. Expert background also contributed significantly to the proportion of occupational causation rated, with COPD experts rating on average a 9.4% greater proportion of occupational causation per case.

CONCLUSION

Our findings support the notion that respiratory physicians are able to assign attribution to different sources of causation in COPD, taking into account both smoking and occupational histories. The recommendations on whether to continue to work in the same job also differ, the COPD experts being more likely to recommend change of work rather than change of work practice.

BACKGROUND

Adjustment for differing risks among patients is usually incorporated into newer payment approaches, and current risk models rely on age, sex, and diagnosis codes. It is unknown the extent to which controlling additionally for disease severity improves cost prediction. Failure to adjust for within-disease variation may create incentives to avoid sicker patients. We address this issue among patients with chronic obstructive pulmonary disease (COPD).

METHODS

Cost and clinical data were collected prospectively from 1202 COPD patients at Kaiser Permanente. Baseline analysis included age, sex, and diagnosis codes (using the Diagnostic Cost Group Relative Risk Score) in a general linear model predicting total medical costs in the following year. We determined whether adding COPD severity measures-forced expiratory volume in 1 second, 6-Minute Walk Test, dyspnea score, body mass index, and BODE Index (composite of the other 4 measures)-improved predictions. Separately, we examined household income as a cost predictor.

RESULTS

Mean costs were $12,334/y. Controlling for Relative Risk Score, each ½ SD worsening in COPD severity factor was associated with $629 to $1135 in increased annual costs (all P<0.01). The lowest stratum of forced expiratory volume in 1 second (<30% normal) predicted $4098 (95% confidence interval, $576-$8773) additional costs. Household income predicted excess costs when added to the baseline model (P=0.038), but this became nonsignificant when also incorporating the BODE Index.

CONCLUSIONS

Disease severity measures explain significant cost variations beyond current risk models, and adding them to such models appears important to fairly compensate organizations that accept responsibility for sicker COPD patients. Appropriately controlling for disease severity also accounts for costs otherwise associated with lower socioeconomic status.

Occupational exposure is a well-recognised modifiable risk factor for asthma, but the relationship between occupational exposure and asthma control has not been studied. We aimed to study this association among working-age adults from the European Community Respiratory Health Survey (ECRHS). Data were available for 7077 participants (mean age 43 years, 45% never-smokers, 5867 without asthma and 1210 with current asthma). Associations between occupational exposure to specific asthmagens and asthma control status (33% with uncontrolled asthma, based on the Global Initiative for Asthma guidelines) were evaluated using logistic and multinomial regressions, adjusted for age, sex and smoking status, with study areas included as a random effect. Statistically significant positive associations were observed between uncontrolled adult-onset asthma and both past 12-month and 10-year exposure to any occupational asthmagens (OR (95% CI) 1.6 (1.0-2.40) and 1.7 (1.2-2.5), respectively); high (1.7 (1.0-2.8) and 1.9 (1.3-2.9), respectively) and low (1.6 (1.0-2.7) and 1.8 (1.2-2.7), respectively) molecular weight agents; and cleaning agents (2.0 (1.1-3.6) and 2.3 (1.4-3.6), respectively), with stronger associations for long-term exposures. These associations were mainly explained by the exacerbation domain of asthma control and no associations were observed between asthmagens and partly controlled asthma. These findings suggest that occupational exposure to asthmagens is associated with uncontrolled adult-onset asthma. Occupational risk factors should be quickly identified to prevent uncontrolled asthma.