AN INVESTIGATION OF THE RELIABILITY AND VALIDITY OF THE CENTER FOR EPIDEMIOLOGIC STUDIES DEPRESSION SCALE IN THREE ETHNIC GROUPS

Epidemiologic studies of mental disorder have called attention to the need for identifying untreated cases and to the inadequacies of the instruments available for this purpose. Accurate case ascertainment devices are the basis of sound epidemiology. Without these, neither case classification nor analytic studies of risk factors is possible.^ The purpose of this research was to examine the reliability and validity of an instrument designed to measure depressive symptoms in community populations--the Center for Epidemiologic Studies Depression Scale (CES-D Scale). Two particular foci of the study were whether or not the scale had the same statistical structure across three ethnic groups and whether or not the magnitude and pattern of rates of symptoms for these groups were affected by one source of response error, that due to response tendencies. The effects of age and education on the pattern and magnitude of rates also were examined. In addition, the reliability and validity of the measures of response tendencies were assessed.^ The study population consisted of residents of Alameda County, California. A stratified sample of approximately 700 whites, blacks and Mexican-Americans was interviewed in the summer and fall of 1978.^ The results of the analysis indicated that the scale was reliable and measured a similar content domain across the three ethnic groups. The unadjusted sex- and ethnic-specific rates of depressive symptoms showed an ethnic pattern for both sexes: rates for whites were lowest, those for Mexican-Americans were highest, and those for blacks were intermediate. Measures of response tendencies--need for social approval, trait desirability, and acquiescence--affected the magnitude of the rates for most comparisons. Likewise, the pattern of rates changed somewhat from that originally observed. The one fairly consistent observation was that rates for Mexican-American women were higher than those for the other two female subgroups in most of the comparisons. These results must be considered in the context of the reliability and validity assessment of the measures of response tendencies which indicated the tenuousness of these measures.^ Age affected the ethnic pattern of rates for men in an inconsistent way; for women, Mexican-Americans continued to have higher rates than whites or blacks in all age categories. Education affected the magnitude of rates for women but not for men. For both men and women, Mexican-Americans had higher rates in all educational strata. Rates for women showed an inverse association with education while those for men did not. ^

AN EPIDEMIOLOGIC DESCRIPTION AND ANALYSIS OF LOST WORKDAY OCCUPATIONAL BURN INJURIES

Background research consisted of a hospital case series of all adult burn patients (n = 162) admitted to John Sealy Hospital's burn unit from January 1978 to June 1979. Comparisons between occupationally and nonoccupationally burned adults demonstrated that occupationally burned adults were significantly more likely to have been active in the burn injury event and to have changed jobs during the prior year. They were significantly less likely to have physical or mental problems which contributed to sustaining the burn injury. Comparisons between occupational and nonoccupational burn injury events concluded that occupational burn injury events were significantly more likely to involve multiple sources of energy, sparks as the source of ignition and gases as the source of combustion. Other salient characteristics of occupational burn injuries indicated that subsequent research should focus upon lost workday occupational burns and other injuries sustained by blue-collar petrochemical workers employed in Galveston County, Texas.^ Subsequent research consisted of a historical cohort study of occupational injuries sustained in 1979 by a cohort of blue-collar petrochemical workers (n = 1771) who belonged to O.C.A.W. Local 4-449 in Texas City, Texas. Specific cohort injury rates included 15.08 occupational injuries per 100 person work-years, 11.98 lost workday occupational injuries per 100 person work-years, and 1.64 lost workday occupational burn injuries per 100 person work-years. Salient results from this study indicate that burn injuries are a very important type (in terms of both frequency and severity) of occupational injury sustained by blue-collar petrochemical workers, pipefitters are at greatest risk of lost workday injuries and lost workday burn injuries, company-specific experiences are comparable for lost workday occupational injuries, differences among company-specific nonlost workday occupational injury experiences may not be "safety-related", and minimal job-specific experience may not place employees at greater risk of lost workday burn injuries.^

A PUBLIC HEALTH SURVEILLANCE SYSTEM FOR THE WESTERN CAYO DISTRICT, BELIZE (DISEASE)

A demonstration project entailing disease surveillance was conducted in the western Cayo District, Belize, from November 1981 to March 1982. The purpose was to test and demonstrate the feasibility of community-based surveillance. Interviews were conducted in three hundred twenty households at monthly intervals over a five-month period. Information regarding disease prevalence and medical care utilization relevant to public health practice was analyzed by staff attached to the health center in Benque Viejo. Data collected at the health center were used to validate reported findings.^ Differences between reported and actual study findings regarding clinic visits were small, though in many instances statistically significant. The proportion of underreported clinic visits was greater than the proportion overreported. Overall, reporting accuracy improved with time, particularly from the first to second month. Clinic utilization experience reported for men was as accurate as that reported for females.^ There was agreement between interview and clinic disease findings. In fact, the proportion of conditions defined in the interview and matched to clinic findings was high (malaria, diarrhea, dysentery, skin sores and ulcerations, and problems of nutrition) except for upper respiratory disorders. Finally, some conditions were more likely to be taken to the health center than others, e.g., children with diarrhea or skin sores and ulcerations were less likely to be taken to the health center than if they had malaria. ^

Burden of invasive pneumococcal disease in Harris County, Texas (2003--2010) and the implication for enhanced public health surveillance of isolates

Invasive pneumococcal disease (IPD) causes significant health burden in the US, is responsible for the majority of bacterial meningitis, and causes more deaths than any other vaccine preventable bacterial disease in the US. The estimated National IPD rate is 14.3 cases per 100,000 population with a case-fatality rate of 1.5 cases per 100,000 population. Although cases of IPD are routinely reported to the local health department in Harris County Texas, the incidence (IR) and case-fatality (CFR) rates have not been reported. Additionally, it is important to know which serotypes of S. pneumoniae are circulating in Harris County Texas and to determine if ‘replacement disease’ is occurring. ^ This study reported incidence and case-fatality rates from 2003 to 2009, and described the trends in IPD, including the IPD serotypes circulating in Harris County Texas during the study period, particularly in 2008 and 2010. Annual incidence rates were calculated and reported for 2003 to 2009, using complete surveillance-year data. ^ Geographic information system (GIS) software was used to create a series of maps of the data reported during the study period. Cluster and outlier analysis and hot spot analysis were conducted using both case counts by census tract and disease rate by census tract. ^ IPD age- and race-adjusted IR for Harris County Texas and their 95% confidence intervals (CIs) were 1.40 (95% CI 1.0, 1.8), 1.71 (95% CI 1.24, 2.17), 3.13 (95% CI 2.48, 3.78), 3.08 (95% CI 2.43, 3.74), 5.61 (95% CI 4.79, 6.43), 8.11 (95% CI 7.11, 9.1), and 7.65 (95% CI 6.69, 8.61) for the years 2003 to 2009, respectively (rates were age- and race-adjusted to each year's midyear US population estimates). A Poisson regression model demonstrated a statistically significant increasing trend of about 32 percent per year in the IPD rates over the course of the study period. IPD age- and race-adjusted case-fatality rates (CFR) for Harris County Texas were also calculated and reported. A Poisson regression model demonstrated a statistically significant increasing trend of about 26 percent per year in the IPD case-fatality rates from 2003 through 2009. A logistic regression model associated the risk of dying from IPD to alcohol abuse (OR 4.69, 95% CI 2.57, 8.56) and to meningitis (OR 2.42, 95% CI 1.46, 4.03). ^ The prevalence of non-vaccine serotypes (NVT) among IPD cases with serotyped isolates was 98.2 percent. In 2008, the year with the sample more geographically representative of all areas of Harris County Texas, the prevalence was 96 percent. Given these findings, it is reasonable to conclude that ‘replacement disease’ is occurring in Harris County Texas, meaning that, the majority of IPD is caused by serotypes not included in the PCV7 vaccine. Also in conclusion, IPD rates increased during the study period in Harris County Texas.^

A descriptive study of syphilis infection in Houston, Texas, 1999--2008

The rate of syphilis nationally has been on the rise since 2001. Syphilis, if left untreated can facilitate the transmission of HIV infection. An epidemiologic study describing the trends of syphilis is important to the public health community to lay the foundation for the development and implementation of programs to prevent and eliminate syphilis in the United States. ^ The objective of this study was to describe the trends of syphilis among the population in Houston/Harris County, Texas. ^ We reviewed surveillance data that included 11,605 unique cases from the Houston Department of Human and Health Service from 1999 through 2008. The rates were calculated per 100,000 population. ^ We show the prevalence of syphilis at testing (excluding congenital) increased 40% in Houston/Harris County, Texas from 2001 through 2008, and the ratio of syphilis comparing men to women was 2:1. The 18–29 years age group had the highest percentage of cases of syphilis among all age groups in Houston/Harris County. Primary and Secondary (P&S) syphilis, the most infectious stage, had an 85% increase in rate among males from 1999 through 2008. ^ Between 1999 and 2000, 71% of cases were identified through public facilities compared to private facilities. However, after 2001 rates shifted over more to the private facilities. By 2008, private facilities identified 54.7% of cases, compared to 45.3% identified through public facilities. This may be due to an increase among individuals who have a higher socio-economic status with access to health care insurance. ^ In conclusion, syphilis rates from 1999 through 2008 increased among all race ethnicities, age groups, and genders in Houston/Harris County. Blacks still are disproportionally affected by syphilis infections, and for the first time, White males displayed a significant increase in cases among males. It is vital to Houston public health professionals to have improved surveillance techniques to track syphilis trends and engage high risk groups to better understand their risks in hope of treating and preventing syphilis.^

Returning Texas Senate Bill 530 back to 1100 Congress Avenue: The need for effective surveillance reporting of student fitness levels to Texas house representatives

Every Texas student is required to complete the FITNESSGRAM fitness assessment under legislation outlined in Senate Bill 530. This study described cardiovascular, body mass index (BMI), and overall fitness levels of students (grades 3–12) in the state of Texas during the 2009–2010 school year, and provides examples of how to effectively present results to Texas House Representatives using three unique health communication strategies. Given the Texas legislature mandates FITNESSGRAM collection yet did not require reporting according to their election district, the data were aggregated to 150 Texas House Representative Districts by sex and grade category to facilitate effective fitness data dissemination. Fitness data were also analyzed with results from the Texas Assessment of Knowledge and Skills (TAKS) to provide insight into potential relationships between fitness and academic achievement. ^ The majority of students in Texas need improvement on at least 1 fitness assessment. In general, female students have superior fitness in elementary and middle school but the fitness edge is erased by high school. Female cardiovascular fitness deteriorates faster from elementary to high school compared to male students. Female BMI deteriorates and male BMI improves from elementary to high school. Cardiovascular fitness and overall fitness decreases from elementary to high school for both male and female students. ^ Student fitness was significantly and strongly independently correlated with academic achievement. Further analysis showed that House Representatives with TAKS scores in the top quartile consistently showed superior fitness. Small significant partial correlations remain between fitness and TAKS assessment after controlling for socioeconomic status. In general, correlations were stronger between female BMI and TAKS assessment compared to male students. Cardiovascular fitness was significantly correlated with TAKS assessment for both genders. This paper supports student fitness as a confounder in the relationship between socioeconomic status and academic achievement. Plus, student fitness has a strong correlation with academic that deserves further exploration. ^ Senate Bill 530 fails to organize and implement a health communication strategy that effectively disseminates the health data collected to stakeholders of interest. The lack of a vital health communication strategy results in an incomplete student health surveillance system. This paper outlines three unique strategies tailored to legislators. It is important to disseminate health information using a variety of methods tailored to your targeted audience. The use of interactive mapping technology presented (GIS) uses new technology that has the potential to effectively reach a large audience.^

Standardization of data collection for the Lifetime Surveillance of Astronaut Health (LSAH)

Problems due to the lack of data standardization and data management have lead to work inefficiencies for the staff working with the vision data for the Lifetime Surveillance of Astronaut Health. Data has been collected over 50 years in a variety of manners and then entered into a software. The lack of communication between the electronic health record (EHR) form designer, epidemiologists, and optometrists has led to some level to confusion on the capability of the EHR system and how its forms can be designed to fit all the needs of the relevant parties. EHR form customizations or form redesigns were found to be critical for using NASA's EHR system in the most beneficial way for its patients, optometrists, and epidemiologists. In order to implement a protocol, data being collected was examined to find the differences in data collection methods. Changes were implemented through the establishment of a process improvement team (PIT). Based on the findings of the PIT, suggestions have been made to improve the current EHR system. If the suggestions are implemented correctly, this will not only improve efficiency of the staff at NASA and its contractors, but set guidelines for changes in other forms such as the vision exam forms. Because NASA is at the forefront of such research and health surveillance the impact of this management change could have a drastic improvement on the collection of and adaptability of the EHR. Accurate data collection from this 50+ year study is ongoing and is going to help current and future generations understand the implications of space flight on human health. It is imperative that the vast amount of information is documented correctly.^

Socioeconomic disparities in thyroid cancer incidence within the Surveillance, Epidemiology, and End Results (SEER) registry, 1980--2008

Background. In the past two decades, the incidence of thyroid cancer in the United States (US) has been increasing. There has been debate on whether the increase is real or an artifact of improved diagnostic scrutiny. Methods. We linked SEER9 database with 2000 US Census to obtain county-level SES (Socioeconomic Status) and compared thyroid cancer incidence trends between high and low SES counties. Joinpoint analysis was used to assess the thyroid cancer incidence trends. Annual Percentage Changes (APCs) were calculated to evaluate incidence trends. Results . The thyroid cancer incidence in high SES counties increased moderately (APC1=+2.5*, *P<0.05) before late 1990s and dramatically increased (APC2=+6.3*) after late 1990s, whereas incidence in low SES counties increased moderately (APC=+3.5*) during the entire time period (1980–2008). For smaller tumors (≤4cm), the APCs in high and low SES counties are similar to each other before late 1990s, but the incidence in high SES counties increased dramatically after late 1990s while that in low SES counties continued at a moderate increase. For large tumors (>4cm), the incidence trends in high SES counties are similar to those of low SES counties, which had a steady moderate increase. Conclusion. Our findings indicate that enhanced detection likely contributed to the increased thyroid cancer incidence in the past decades but cannot fully explain the increase, suggesting that a true increase also exists. Efforts should be made on identifying the cause of this observed increased incidence as well as more refined/selected screening and prevention measures.^

Implementation of active surveillance cultures and associated infection control practices for the reduction of methicillin resistant Staphylococcus aureus in the healthcare setting: An interrupted time series analysis

OBJECTIVE. To determine the effectiveness of active surveillance cultures and associated infection control practices on the incidence of methicillin resistant Staphylococcus aureus (MRSA) in the acute care setting. DESIGN. A historical analysis of existing clinical data utilizing an interrupted time series design. ^ SETTING AND PARTICIPANTS. Patients admitted to a 260-bed tertiary care facility in Houston, TX between January 2005 through December 2010. ^ INTERVENTION. Infection control practices, including enhanced barrier precautions, compulsive hand hygiene, disinfection and environmental cleaning, and executive ownership and education, were simultaneously introduced during a 5-month intervention implementation period culminating with the implementation of active surveillance screening. Beginning June 2007, all high risk patients were cultured for MRSA nasal carriage within 48 hours of admission. Segmented Poisson regression was used to test the significance of the difference in incidence of healthcare-associated MRSA during the 29-month pre-intervention period compared to the 43-month post-intervention period. ^ RESULTS. A total of 9,957 of 11,095 high-risk patients (89.7%) were screened for MRSA carriage during the intervention period. Active surveillance cultures identified 1,330 MRSA-positive patients (13.4%) contributing to an admission prevalence of 17.5% in high-risk patients. The mean rate of healthcare-associated MRSA infection and colonization decreased from 1.1 per 1,000 patient-days in the pre-intervention period to 0.36 per 1,000 patient-days in the post-intervention period (P<0.001). The effect of the intervention in association with the percentage of S. aureus isolates susceptible to oxicillin were shown to be statistically significantly associated with the incidence of MRSA infection and colonization (IRR = 0.50, 95% CI = 0.31-0.80 and IRR = 0.004, 95% CI = 0.00003-0.40, respectively). ^ CONCLUSIONS. It can be concluded that aggressively targeting patients at high risk for colonization of MRSA with active surveillance cultures and associated infection control practices as part of a multifaceted, hospital-wide intervention is effective in reducing the incidence of healthcare-associated MRSA.^

Simultaneous induction of NKG2D and NKG2D ligand for promoting immune surveillance by IL-12 plus doxorubicin treatment

NKG2D (natural killer group 2, member D) and its ligands interaction in tumor microenvironment directs tumor infiltrating immune cells to recognize tumor cells, stimulate cytotoxic effector immune cells, and therefore eradicate tumor cells. IL-12, a cytokine produced by antigen presenting cells, has remarkable antitumor effect by activating innate and adaptive immunity. Doxorubicin, a commonly used chemotherapeutic agent also boosts the host antitumor immune response to cause tumor cell death. Our previous publication suggests that IL-12 plus doxorubicin enhances NKG2D function-dependent inhibition of tumor progression and promotes CD8+T cells infiltrating into tumors. The purpose of this study is to determine the underlying mechanism. Our study reveals a novel function of doxorubicin, which is to augment IL-12–induced NKG2D expression in CD8+T cells but not in NK or CD4+T cells. This observation was further validated by NK and CD8+T cell-depletion studies, in which only depletion of CD8+T cells abolished the expression of NKG2D in lymphocytes. The induced NKG2D expression in CD8+T cells is tightly associated with tumor-specific localization of CD8+T cells and improved antitumor efficacy. The IL-12 plus doxorubicin treatment-induced antitumor efficacy is also due to NKG2D ligand Rae-1 induction in tumors. Rae-1 induction in tumors is a long term effect in multiple tumor models, but not in normal tissues. A novel CD8+T cell direct contact dependent mechanism accounts for Rae-1 induction in vivo and in vitro, and CD80 is the receptor through which CD8+T cells interplay with tumor cells to upregulate Rae-1 on tumor cells. In summary, increased NKG2D expression in CD8+T cells in response to IL-12 plus doxorubicin was closely associated with tumor-specific localization of CD8+T cells and greater antitumor efficacy of the combined regimen than either agent alone. NKG2D ligand Rae-1 induction is triggered by the interaction of CD80 on tumor cells with tumor infiltrating CD+8 T cells.

Literature review of estimation of prevalence rate of HIV/AIDS in India using population survey and sentinel surveillance based data

HIV/AIDS is a treatable although incurable disease that presents immense challenges to those infected including physical, social and psychological effects. As of 2009, an estimated 2.4 million people were living with HIV or AIDS in India, 0.3% of the country's population. In India, it is difficult to not only treat but also to track because it is associated with socio-economic factors such as illiteracy, social biases, poor sanitation, malnutrition and social class. Nevertheless, it is important to know the prevalence of HIV/AIDS for several reasons. At the individual level, the quality of life of people living with HIV/AIDS is markedly lower than their counterparts without the disease and is associated with challenges. At the community level, it is important to identify high risk groups, monitor prevention efforts, and allocate appropriate resources to target programs for the reduction of transmission of HIV. ^

A comparative state policy analysis of the adoption of birth defects surveillance legislation

Birth defects are the leading cause of infant mortality in the United States and are a major cause of lifetime disability. However, efforts to understand their causes have been hampered by a lack of population-specific data. During 1990–2004, 22 state legislatures responded to this need by proposing birth defects surveillance legislation (BDSL). The contrast between these states and those that did not pass BDSL provides an opportunity to better understand conditions associated with US public health policy diffusion. ^ This study identifies key state-specific determinants that predict: (1) the introduction of birth defects surveillance legislation (BDSL) onto states' formal legislative agenda, and (2) the successful adoption of these laws. Secondary aims were to interpret these findings in a theoretically sound framework and to incorporate evidence from three analytical approaches. ^ The study begins with a comparative case study of Texas and Oregon (states with divergent BDSL outcomes), including a review of historical documentation and content analysis of key informant interviews. After selecting and operationalizing explanatory variables suggested by the case study, Qualitative Comparative Analysis (QCA) was applied to publically available data to describe important patterns of variation among 37 states. Results from logistic regression were compared to determine whether the two methods produced consistent findings. ^ Themes emerging from the comparative case study included differing budgetary conditions and the significance of relationships within policy issue networks. However, the QCA and statistical analysis pointed to the importance of political parties and contrasting societal contexts. Notably, state policies that allow greater access to citizen-driven ballot initiatives were consistently associated with lower likelihood of introducing BDSL. ^ Methodologically, these results indicate that a case study approach, while important for eliciting valuable context-specific detail, may fail to detect the influence of overarching, systemic variables, such as party competition. However, QCA and statistical analyses were limited by a lack of existing data to operationalize policy issue networks, and thus may have downplayed the impact of personal interactions. ^ This study contributes to the field of health policy studies in three ways. First, it emphasizes the importance of collegial and consistent relationships among policy issue network members. Second, it calls attention to political party systems in predicting policy outcomes. Finally, a novel approach to interpreting state data in a theoretically significant manner (QCA) has been demonstrated.^

Novel Imaging-Based Techniques Reveal a Role for PD-1/PD-L1 in Tumor Immune Surveillance in the Lung

The binding of immune inhibitory receptor Programmed Death 1 (PD-1) on T cells to its ligand PD-L1 has been implicated as a major contributor to tumor induced immune suppression. Clinical trials of PD-L1 blockade have proven effective in unleashing therapeutic anti-tumor immune responses in a subset of patients with advanced melanoma, yet current response rates are low for reasons that remain unclear. Hypothesizing that the PD-1/PD-L1 pathway regulates T cell surveillance within the tumor microenvironment, we employed intravital microscopy to investigate the in vivo impact of PD-L1 blocking antibody upon tumor-associated immune cell migration. However, current analytical methods of intravital dynamic microscopy data lack the ability to identify cellular targets of T cell interactions in vivo, a crucial means for discovering which interactions are modulated by therapeutic intervention. By developing novel imaging techniques that allowed us to better analyze tumor progression and T cell dynamics in the microenvironment; we were able to explore the impact of PD-L1 blockade upon the migratory properties of tumor-associated immune cells, including T cells and antigen presenting cells, in lung tumor progression. Our results demonstrate that early changes in tumor morphology may be indicative of responsiveness to anti-PD-L1 therapy. We show that immune cells in the tumor microenvironment as well as tumors themselves express PD-L1, but immune phenotype alone is not a predictive marker of effective anti-tumor responses. Through a novel method in which we quantify T cell interactions, we show that T cells are largely engaged in interactions with dendritic cells in the tumor microenvironment. Additionally, we show that during PD-L1 blockade, non-activated T cells are recruited in greater numbers into the tumor microenvironment and engage more preferentially with dendritic cells. We further show that during PD-L1 blockade, activated T cells engage in more confined, immune synapse-like interactions with dendritic cells, as opposed to more dynamic, kinapse-like interactions with dendritic cells when PD-L1 is free to bind its receptor. By advancing the contextual analysis of anti-tumor immune surveillance in vivo, this study implicates the interaction between T cells and tumor-associated dendritic cells as a possible modulator in targeting PD-L1 for anti-tumor immunotherapy.

Use of a modified delphi process for establishing occupational exposure limits in support of health surveillance for space travelers

On-orbit exposures can come from numerous factors related to the space environment as evidenced by almost 50 years of environmental samples collected for water analysis, air analysis, radiation analysis, and physiologic parameters. For astronauts and spaceflight participants the occupational exposures can be very different from those experienced by workers performing similar tasks in workplaces on Earth, because the duration of the exposure could be continuous for very long orbital, and eventually interplanetary, missions. The establishment of long-term exposure standards is vital to controlling the quality of the spacecraft environment over long periods. NASA often needs to update and revise its prior exposure standards (Spacecrafts Maximum Allowable Concentrations (SMACs)). Traditional standards-setting processes are often lengthy, so a more rapid method to review and establish standards would be a substantial advancement in this area. This project investigates use of the Delphi method for this purpose. ^ In order to achieve the objectives of this study a modified Delphi methodology was tested in three trials executed by doctoral students and a panel of experts in disciplines related to occupational safety and health. During each test/trial modifications were made to the methodology. Prior to submission of the Delphi Questionnaire to the panel of experts a pilot study/trial was conducted using five doctoral students with the goals of testing and adjusting the Delphi questionnaire to improve comprehension, work out any procedural issues and evaluate the effectiveness of the questionnaire in drawing the desired responses. The remainder of the study consisted of two trials of the Modified Delphi process using 6 chemicals that currently have the potential of causing occupational exposures to NASA astronauts or spaceflight participants. To assist in setting Occupational Exposure Limits (OEL), the expert panel was established consisting of experts from academia, government and industry. Evidence was collected and used to create close-ended questionnaires which were submitted to the Delphi panel of experts for the establishment of OEL values for three chemicals from the list of six originally selected (trial 1). Once the first Delphi trial was completed, adjustments were made to the Delphi questionnaires and the process above was repeated with the remaining 3 chemicals (trial 2). ^ Results indicate that experience in occupational safety and health and with OEL methodologies can have a positive effect in minimizing the time experts take in completing this process. Based on the results of the questionnaires and comparison of the results with the SMAC already established by NASA, we conclude that use of the Delphi methodology is appropriate for use in the decision-making process for the selection of OELs.^