LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 42

Search options

  1. Article ; Online: Compare the marginal effects for environmental exposure and biomonitoring data with repeated measurements and values below the limit of detection.

    Chen, I-Chen / Bertke, Stephen J / Estill, Cheryl Fairfield

    Journal of exposure science & environmental epidemiology

    2024  

    Abstract: Background: Environmental exposure and biomonitoring data with repeated measurements from environmental and occupational studies are commonly right-skewed and in the presence of limits of detection (LOD). However, existing model has not been discussed ... ...

    Abstract Background: Environmental exposure and biomonitoring data with repeated measurements from environmental and occupational studies are commonly right-skewed and in the presence of limits of detection (LOD). However, existing model has not been discussed for small-sample properties and highly skewed data with non-detects and repeated measurements.
    Objective: Marginal modeling provides an alternative to analyzing longitudinal and cluster data, in which the parameter interpretations are with respect to marginal or population-averaged means.
    Methods: We outlined the theories of three marginal models, i.e., generalized estimating equations (GEE), quadratic inference functions (QIF), and generalized method of moments (GMM). With these approaches, we proposed to incorporate the fill-in methods, including single and multiple value imputation techniques, such that any measurements less than the limit of detection are assigned values.
    Results: We demonstrated that the GEE method works well in terms of estimating the regression parameters in small sample sizes, while the QIF and GMM outperform in large-sample settings, as parameter estimates are consistent and have relatively smaller mean squared error. No specific fill-in method can be deemed superior as each has its own merits.
    Impact: Marginal modeling is firstly employed to analyze repeated measures data with non-detects, in which only the mean structure needs to be correctly provided to obtain consistent parameter estimates. After replacing non-detects through substitution methods and utilizing small-sample bias corrections, in a simulation study we found that the estimating approaches used in the marginal models have corresponding advantages under a wide range of sample sizes. We also applied the models to longitudinal and cluster working examples.
    Language English
    Publishing date 2024-01-22
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2218551-3
    ISSN 1559-064X ; 1559-0631
    ISSN (online) 1559-064X
    ISSN 1559-0631
    DOI 10.1038/s41370-024-00640-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Introducing LTASR, a new R package based on the NIOSH Life Table Analysis System.

    Bertke, Stephen J / Kelly-Reif, Kaitlin

    Occupational and environmental medicine

    2022  

    Language English
    Publishing date 2022-09-20
    Publishing country England
    Document type Letter
    ZDB-ID 1180733-7
    ISSN 1470-7926 ; 1351-0711
    ISSN (online) 1470-7926
    ISSN 1351-0711
    DOI 10.1136/oemed-2022-108462
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Exposure-response assessment of cancer mortality in styrene-exposed boatbuilders.

    Daniels, Robert Douglas / Bertke, Stephen J

    Occupational and environmental medicine

    2020  Volume 77, Issue 10, Page(s) 706–712

    Abstract: Objectives: To improve exposure estimates and reexamine exposure-response relationships between cumulative styrene exposure and cancer mortality in a previously studied cohort of US boatbuilders exposed between 1959 and 1978 and followed through 2016.!## ...

    Abstract Objectives: To improve exposure estimates and reexamine exposure-response relationships between cumulative styrene exposure and cancer mortality in a previously studied cohort of US boatbuilders exposed between 1959 and 1978 and followed through 2016.
    Methods: Cumulative styrene exposure was estimated from work assignments and air-sampling data. Exposure-response relationships between styrene and select cancers were examined in Cox proportional hazards models matched on attained age, sex, race, birth cohort and employment duration. Models adjusted for socioeconomic status (SES). Exposures were lagged 10 years or by a period maximising the likelihood. HRs included 95% profile-likelihood CIs. Actuarial methods were used to estimate the styrene exposure corresponding to 10
    Results: The cohort (n= 5163) contributed 201 951 person-years. Exposures were right-skewed, with mean and median of 31 and 5.7 ppm-years, respectively. Positive, monotonic exposure-response associations were evident for leukaemia (HR at 50 ppm-years styrene = 1.46; 95% CI 1.04 to 1.97) and bladder cancer (HR at 50 ppm-years styrene =1.64; 95% CI 1.14 to 2.33). There was no evidence of confounding by SES. A working lifetime exposure to 0.05 ppm styrene corresponded to one extra leukaemia death per 10 000 workers.
    Conclusions: The study contributes evidence of exposure-response associations between cumulative styrene exposure and cancer. Simple risk projections at current exposure levels indicate a need for formal risk assessment. Future recommendations on worker protection would benefit from additional research clarifying cancer risks from styrene exposure.
    MeSH term(s) Adult ; Cohort Studies ; Construction Materials/adverse effects ; Construction Materials/statistics & numerical data ; Female ; Humans ; Male ; Middle Aged ; Neoplasms/epidemiology ; Neoplasms/mortality ; Occupational Exposure/adverse effects ; Occupational Exposure/statistics & numerical data ; Proportional Hazards Models ; Risk Factors ; Ships/statistics & numerical data ; Social Class ; Styrene/adverse effects ; Washington/epidemiology ; Workplace/standards ; Workplace/statistics & numerical data
    Chemical Substances Styrene (44LJ2U959V)
    Language English
    Publishing date 2020-05-29
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1180733-7
    ISSN 1470-7926 ; 1351-0711
    ISSN (online) 1470-7926
    ISSN 1351-0711
    DOI 10.1136/oemed-2020-106445
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Lung Cancer Mortality and Styrene Exposure in the Reinforced-Plastics Boatbuilding Industry: Evaluation of Healthy Worker Survivor Bias.

    Bertke, Stephen J / Keil, Alexander P / Daniels, Robert D

    American journal of epidemiology

    2021  Volume 190, Issue 9, Page(s) 1784–1792

    Abstract: The evidence for styrene's being a human lung carcinogen has been inconclusive. Occupational cohorts within the reinforced-plastics industry are an ideal population in which to study this association because of their relatively high levels of exposure to ...

    Abstract The evidence for styrene's being a human lung carcinogen has been inconclusive. Occupational cohorts within the reinforced-plastics industry are an ideal population in which to study this association because of their relatively high levels of exposure to styrene and lack of concomitant exposures to other known carcinogens. However, healthy worker survivor bias (HWSB), where healthier workers stay employed longer and thus have higher exposure potential, is a likely source of confounding bias for exposure-response associations, in part due to styrene's acute effects. Through December 31, 2016, we studied a cohort of 5,163 boatbuilders exposed to styrene in Washington State who were employed between 1959 and 1978; prior regression analyses had demonstrated little evidence for an exposure-response relationship between styrene exposure and lung cancer mortality. Based on estimates of necessary components of HWSB, we found evidence for a potentially large HWSB. Using g-estimation of a structural nested model to account for HWSB, we estimated that 1 year of styrene exposure at more than 30 parts per million accelerated time to lung cancer death by 2.29 years (95% confidence interval: 1.53, 2.94). Our results suggest possibly strong HWSB in our small cohort and indicate that large, influential studies of styrene-exposed workers may suffer from similar biases, warranting a reassessment of the evidence of long-term health effects of styrene exposure.
    MeSH term(s) Aged ; Bias ; Dose-Response Relationship, Drug ; Female ; Humans ; Lung Neoplasms/chemically induced ; Lung Neoplasms/mortality ; Male ; Manufacturing Industry/statistics & numerical data ; Middle Aged ; Models, Statistical ; Occupational Exposure/adverse effects ; Plastics/toxicity ; Regression Analysis ; Ships ; Styrene/toxicity ; Survivors/statistics & numerical data ; Washington/epidemiology
    Chemical Substances Plastics ; Styrene (44LJ2U959V)
    Language English
    Publishing date 2021-04-13
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2937-3
    ISSN 1476-6256 ; 0002-9262
    ISSN (online) 1476-6256
    ISSN 0002-9262
    DOI 10.1093/aje/kwab108
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Quantile regression for exposure data with repeated measures in the presence of non-detects.

    Chen, I-Chen / Bertke, Stephen J / Curwin, Brian D

    Journal of exposure science & environmental epidemiology

    2021  Volume 31, Issue 6, Page(s) 1057–1066

    Abstract: Background: Exposure data with repeated measures from occupational studies are frequently right-skewed and left-censored. To address right-skewed data, data are generally log-transformed and analyses modeling the geometric mean operate under the ... ...

    Abstract Background: Exposure data with repeated measures from occupational studies are frequently right-skewed and left-censored. To address right-skewed data, data are generally log-transformed and analyses modeling the geometric mean operate under the assumption the data are log-normally distributed. However, modeling the mean of exposure may lead to bias and loss of efficiency if the transformed data do not follow a known distribution. In addition, left censoring occurs when measurements are below the limit of detection (LOD).
    Objective: To present a complete illustration of the entire conditional distribution of an exposure outcome by examining different quantiles, rather than modeling the mean.
    Methods: We propose an approach combining the quantile regression model, which does not require any specified error distributions, with the substitution method for skewed data with repeated measurements and non-detects.
    Results: In a simulation study and application example, we demonstrate that this method performs well, particularly for highly right-skewed data, as parameter estimates are consistent and have smaller mean squared error relative to existing approaches.
    Significance: The proposed approach provides an alternative insight into the conditional distribution of an exposure outcome for repeated measures models.
    MeSH term(s) Bias ; Computer Simulation ; Humans ; Limit of Detection ; Models, Statistical
    Language English
    Publishing date 2021-06-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2218551-3
    ISSN 1559-064X ; 1559-0631
    ISSN (online) 1559-064X
    ISSN 1559-0631
    DOI 10.1038/s41370-021-00345-1
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Health burdens of uranium miners will extend beyond the radiation exposure compensation act deadline.

    Kelly-Reif, Kaitlin / Bertke, Stephen J / Samet, Jonathan / Sood, Akshay / Schubauer-Berigan, Mary K

    Occupational and environmental medicine

    2022  

    Language English
    Publishing date 2022-05-02
    Publishing country England
    Document type Letter
    ZDB-ID 1180733-7
    ISSN 1470-7926 ; 1351-0711
    ISSN (online) 1470-7926
    ISSN 1351-0711
    DOI 10.1136/oemed-2022-108311
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Cancer incidence among boat-building workers exposed to styrene.

    Ruder, Avima M / Bertke, Stephen J

    American journal of industrial medicine

    2017  Volume 60, Issue 7, Page(s) 651–657

    Abstract: Background: A cancer incidence analysis was conducted on The National Institute for Occupational Safety and Health boat-builders cohort exposed to styrene, a possible carcinogen.: Methods: Standardized incidence ratios (SIR) and standardized rate ... ...

    Abstract Background: A cancer incidence analysis was conducted on The National Institute for Occupational Safety and Health boat-builders cohort exposed to styrene, a possible carcinogen.
    Methods: Standardized incidence ratios (SIR) and standardized rate ratios (SRR) were calculated using national and Washington State rates and a person-years analysis program.
    Results: Among 3704 workers living in Washington State after 1991, when cancer registry case accrual began, 516 first primary diagnoses occurred through 2007. While overall cancer incidence was significantly reduced [SIR: 0.83 (0.76, 0.90)], internal comparisons suggest an association with exposure comparing high to low exposed person-time [SRR: 1.28 (1.05, 1.55)].
    Conclusion: There is evidence of styrene exposure being linked to cancer incidence, which is notable since the cohort has not yet reached the median age of cancer diagnosis (65) in the United States.
    Language English
    Publishing date 2017-07
    Publishing country United States
    Document type Journal Article
    ZDB-ID 604538-8
    ISSN 1097-0274 ; 0271-3586
    ISSN (online) 1097-0274
    ISSN 0271-3586
    DOI 10.1002/ajim.22735
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: The effectiveness of ergonomic interventions in material handling operations.

    Wurzelbacher, Steven J / Lampl, Michael P / Bertke, Stephen J / Tseng, Chih-Yu

    Applied ergonomics

    2020  Volume 87, Page(s) 103139

    Abstract: This study evaluated the effectiveness of ergonomic interventions in material handling operations involving 33 employers and 535 employees from 2012 to 2017. Outcomes included employee-reported low back/upper extremity pain and safety incidents at ... ...

    Abstract This study evaluated the effectiveness of ergonomic interventions in material handling operations involving 33 employers and 535 employees from 2012 to 2017. Outcomes included employee-reported low back/upper extremity pain and safety incidents at baseline, every three months, and annually for up to two years. A total of 32.5% of employees completed at least one survey, while 13.6% completed all nine surveys over two years. Among highly exposed employees (who reported handling >= 50 lbs. > 33% of the time), upper extremity pain frequency and severity were lower among those who reported using the intervention routinely versus those that reported using their body strength alone to handle objects >= 50 lbs. After excluding from analyses one employer that used anti-fatigue mats, low back pain frequency was also significantly lower among highly exposed intervention users. In conclusion, there was some evidence that the interventions were effective in reducing employee-reported pain for highly exposed employees.
    MeSH term(s) Adult ; Ergonomics ; Female ; Humans ; Lifting ; Low Back Pain/etiology ; Low Back Pain/prevention & control ; Male ; Manufactured Materials ; Manufacturing Industry ; Middle Aged ; Musculoskeletal Pain/etiology ; Musculoskeletal Pain/prevention & control ; Occupational Diseases/etiology ; Occupational Diseases/prevention & control ; Outcome Assessment, Health Care ; Upper Extremity ; Weight-Bearing/physiology ; Work/physiology
    Language English
    Publishing date 2020-05-08
    Publishing country England
    Document type Evaluation Study ; Journal Article
    ZDB-ID 2003513-5
    ISSN 1872-9126 ; 0003-6870
    ISSN (online) 1872-9126
    ISSN 0003-6870
    DOI 10.1016/j.apergo.2020.103139
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Cancer mortality update with an exposure response analysis among styrene-exposed workers in the reinforced plastics boatbuilding industry.

    Bertke, Stephen J / Yiin, James H / Daniels, Robert D

    American journal of industrial medicine

    2018  Volume 61, Issue 7, Page(s) 566–571

    Abstract: Background: There is sparse and inconsistent evidence of an association between styrene exposure and cancer.: Methods: This study examines mortality patterns in a previously studied cohort of 5201 workers employed in two Washington boat-building ... ...

    Abstract Background: There is sparse and inconsistent evidence of an association between styrene exposure and cancer.
    Methods: This study examines mortality patterns in a previously studied cohort of 5201 workers employed in two Washington boat-building facilities, extending follow-up 5 years. Standardized mortality ratios (SMR) were calculated using state rates as referent. Cox regression calculated rate ratios (RR) per year employed in styrene-exposed exposed jobs.
    Results: No excess deaths from lymphohematopoietic cancers (LHCs) were observed (SMR: 0.99, 95%CI: 0.74-1.30) when compared to the referent population; however, the relative risk increased with duration of employment in internal analyses. Conversely, lung cancer mortality was significantly elevated (SMR: 1.24, 95%CI: 1.08-1.41), but there was no evidence of a dose-response relationship.
    Conclusion: We found evidence that occupational exposure to styrene was associated with increased LHC risk, while no such association was observed for lung cancer.
    MeSH term(s) Aged ; Cohort Studies ; Employment ; Female ; Hematologic Neoplasms/mortality ; Humans ; Leukemia/mortality ; Lung Neoplasms/mortality ; Lymphoma, Non-Hodgkin/mortality ; Male ; Manufacturing Industry ; Middle Aged ; Multiple Myeloma/mortality ; Neoplasms/mortality ; Occupational Exposure/statistics & numerical data ; Plastics ; Proportional Hazards Models ; Ships ; Styrene ; Time Factors ; Washington/epidemiology
    Chemical Substances Plastics ; Styrene (44LJ2U959V)
    Language English
    Publishing date 2018-04-11
    Publishing country United States
    Document type Journal Article
    ZDB-ID 604538-8
    ISSN 1097-0274 ; 0271-3586
    ISSN (online) 1097-0274
    ISSN 0271-3586
    DOI 10.1002/ajim.22853
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: The Impact of a State-Based Workers' Compensation Insurer's Risk Control Services on Employer Claim Frequency and Cost Rates.

    Wurzelbacher, Steven J / Bertke, Stephen J / Lampl, Michael P / Bushnell, P Timothy / Robins, David C / Naber, Steven J / Moore, Libby L

    Journal of occupational and environmental medicine

    2022  Volume 64, Issue 7, Page(s) 562–572

    Abstract: Objective: This study evaluated the impact of a state workers' compensation (WC) insurer's onsite risk control (RC) services on insured employers' WC claim frequency and cost.: Methods: We used two methods to model 2004 to 2017 claims data from 4606 ... ...

    Abstract Objective: This study evaluated the impact of a state workers' compensation (WC) insurer's onsite risk control (RC) services on insured employers' WC claim frequency and cost.
    Methods: We used two methods to model 2004 to 2017 claims data from 4606 employers that received RC visits over time and compare this claims experience to matching employers that did not receive RC services.
    Results: Relative total WC claim rates increased slightly after RC services, while relative lost-time claims rates either remained similar or decreased and WC cost rates decreased. The impact of RC services on reducing WC costs was cumulative up to the fourth visit but diminished thereafter.
    Conclusions: The insurer RC consultation program was effective in reducing WC cost rates for serviced employers. This is consistent with other research conducted on insurer RC services and related regulatory visits.
    MeSH term(s) Humans ; Insurance Carriers ; Workers' Compensation
    Language English
    Publishing date 2022-02-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1223932-x
    ISSN 1536-5948 ; 1076-2752
    ISSN (online) 1536-5948
    ISSN 1076-2752
    DOI 10.1097/JOM.0000000000002508
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top