Re-scaling and small area estimation of behavioral risk survey guided by social vulnerability data.

BACKGROUND: Local governments and other public health entities often need population health measures at the county or subcounty level for activities such as resource allocation and targeting public health interventions, among others. Information collected via national surveys alone cannot fill these needs. We propose a novel, two-step method for rescaling health survey data and creating small area estimates (SAEs) of smoking rates using a Behavioral Risk Factor Surveillance System survey administered in 2015 to participants living in Allegheny County, Pennsylvania, USA. METHODS: The first step consisted of a spatial microsimulation to rescale location of survey respondents from zip codes to tracts based on census population distributions by age, sex, race, and education. The rescaling allowed us, in the second step, to utilize available census tract-specific ancillary data on social vulnerability for small area estimation of local health risk using an area-level version of a logistic linear mixed model. To demonstrate this new two-step algorithm, we estimated the ever-smoking rate for the census tracts of Allegheny County. RESULTS: The ever-smoking rate was above 70% for two census tracts to the southeast of the city of Pittsburgh. Several tracts in the southern and eastern sections of Pittsburgh also had relatively high (> 65%) ever-smoking rates. CONCLUSIONS: These SAEs may be used in local public health efforts to target interventions and educational resources aimed at reducing cigarette smoking. Further, our new two-step methodology may be extended to small area estimation for other locations and health outcomes.

Liver kidney microsome antibodies. Analysis of a laboratory series.

Objectives: The objectives were to characterize the liver kidney microsome (LKM) antibody profile of a 14-month-old girl with autoimmune hepatitis and analyze the laboratory prevalence of LKM positivity. Design and methods: This is retrospective analysis of the LKM antibody immunofluorescence tests performed by the Immunology Laboratory of Johns Hopkins Hospital from September 8, 2020 to July 31, 2022. LKM positive sera were also tested by an ELISA for LKM1 antibodies, which recognize the cytochrome P450 2D6 antigen. In silico analysis of 2D6 mRNA expression across anatomical sites was performed using Bgee and GTEx Portal databases. Results: Of the total of 1598 patients (893 F, 705 M, ages 0.8-94 years) tested for LKM antibodies, 3 were positive, yielding a 0.2% period prevalence. The clinical diagnosis was autoimmune hepatitis in the index case, acute viral hepatitis in a 3-yo male, and hepatocellular carcinoma in a 54-yo male. LKM antibodies yielded the classical homogenous staining pattern in the liver cytosol and proximal kidney tubular cells. The first two patients were also positive for LKM1 antibodies, whereas the third was negative. 2D6 mRNA was expressed highly in the liver, moderately in the duodenum, and minimally in other tissues. Conclusions: Overall, LKM antibodies are rare. They contribute to establish a diagnosis of autoimmune hepatitis, although they are also found in other liver diseases. The cytochrome P450 2D6 is one of the antigens recognized by LKM antibodies, but other antigens are likely targeted considering that 2D6 is minimally expressed in the kidney and yet LKM antibodies bind to kidney tubuli.

Cultural Influences on Mental Health Provision in the Caribbean: How Do Contemporary Perceptions and Beliefs About Persons With Mental Illness Inform Workforce Transformation?

INTRODUCTION: Mental illness is a global phenomenon in society, including trained health professionals, often responding to people with mental illness based on perceptions and beliefs. The research examined "contemporary perceptions and beliefs about mental illness held by stakeholders" attending a mental health symposium in Trinidad. METHODS: Data were collected using a 43-item questionnaire and analyzed using SPSS Version 22. Overall, 84 attendees working directly or experienced in mental health completed the survey. RESULTS: Respondents believed mental illness should be treated within local community settings. Participants who were more comfortable sharing their mental health diagnosis with friends were more likely to share with others, including their employers. There was a relationship between perception of the superstitious causes of mental illness and its effects on healing. DISCUSSION: Qualifications and experience in mental health do not reduce stigma associated with mental illness which has implications for addressing mental health literacy among health professionals.

Randomized controlled trial of the "WISER" intervention to reduce healthcare worker burnout.

OBJECTIVE: Test web-based implementation for the science of enhancing resilience (WISER) intervention efficacy in reducing healthcare worker (HCW) burnout. DESIGN: RCT using two cohorts of HCWs of four NICUs each, to improve HCW well-being (primary outcome: burnout). Cohort 1 received WISER while Cohort 2 acted as a waitlist control. RESULTS: Cohorts were similar, mostly female (83%) and nurses (62%). In Cohorts 1 and 2 respectively, 182 and 299 initiated WISER, 100 and 176 completed 1-month follow-up, and 78 and 146 completed 6-month follow-up. Relative to control, WISER decreased burnout (-5.27 (95% CI: -10.44, -0.10), p = 0.046). Combined adjusted cohort results at 1-month showed that the percentage of HCWs reporting concerning outcomes was significantly decreased for burnout (-6.3% (95%CI: -11.6%, -1.0%); p = 0.008), and secondary outcomes depression (-5.2% (95%CI: -10.8, -0.4); p = 0.022) and work-life integration (-11.8% (95%CI: -17.9, -6.1); p < 0.001). Improvements endured at 6 months. CONCLUSION: WISER appears to durably improve HCW well-being. CLINICAL TRIALS NUMBER: NCT02603133; https://clinicaltrials.gov/ct2/show/NCT02603133.

Nurses' preparation for transitioning into positions of leadership-A Caribbean perspective.

AIM: To explore perspectives of nurse managers about their preparation for transitioning into positions of leadership. BACKGROUND: There have been serious concerns about the level of preparation as well as availability of support systems for transitioning of nurses into positions of authority. METHODS: This was a quantitative study conducted in four Caribbean countries targeting nurses promoted to leadership positions within the last 5 years. Data were collected using a 30-item questionnaire. Ethical approvals were received from the University of the West Indies and the participating countries. RESULTS: Most participants were female, had 15 or more years' experience and an associate degree/diploma in nursing. They felt prepared through training and acting opportunities although many were not preceptored/mentored into the position. Preparation by training was positively correlated to acting opportunities, preceptorship programme and having a preceptor. CONCLUSION: Transitioning into positions of leadership requires readiness from a personal as well as an organisational perspective. There must be investment in the development opportunities to support nurses' transition into leadership positions. IMPLICATIONS FOR NURSING MANAGEMENT: Organisational continuity and effectiveness will be dependent on a balance between investing in experienced nursing personnel while encouraging personal development of less-experienced nurses. Peer mentorship must be utilized to facilitate nurse transition.

Interventions to promote healthy environments in family child care homes in Oklahoma-Happy Healthy Homes: study protocol for a randomized controlled trial.

BACKGROUND: Early childhood is a critical period of development. Caregivers, including providers of early care and education (ECE), have a substantial influence on the health of young children. Family child care homes (FCCHs), which are small, licensed ECE businesses operated out of the residences of providers, are important settings for promoting child health. However, to date, few interventions to promote the health of children have been developed for FCCHs. The purpose of this article is to describe the protocol for Happy Healthy Homes, a pilot interdisciplinary, community-based study to improve FCCH environments and the health of children in Oklahoma. We describe the development and evaluation of two interventions to be tested in a matched attention randomized controlled trial: 1) a nutrition intervention aimed at enhancing the nutritional quality of meals served to young children, incorporating the Child and Adult Care Food Program best practices, and improving nutritional self-efficacy of providers; and 2) an environmental intervention aimed at increasing providers' environmental health literacy, self-efficacy for integrated pest management (IPM), and awareness of less toxic cleaning practices and FCCH provider cleaning behaviors. METHODS: Both interventions are informed by common theoretical principles and are matched in attention (i.e., 6 h), format (i.e., two individual 90-min educational home visits and a 3-h small group class) and materials (i.e., tool kit of educational materials and supplies tailored to the allocated intervention). A randomized trial of both interventions is currently underway with 52 FCCH providers in the Oklahoma City metropolitan area who participate in the Child and Adult Care Food Program. Observed and self-reported measures will be collected at baseline, and 3 months and 12 months after baseline measurements. Randomization to one of the two interventions will occur after baseline data collection. DISCUSSION: This study aims to support FCCH providers in creating healthier FCCH environments for nutrition and environmental health. Successful completion will provide critical information about the nutritional quality and the environmental health of children in FCCHs, as well as much needed evidence about the efficacy of two community-based interventions to improve the nutrition and environmental health of children in home-based ECE settings. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03560050 . Retrospectively registered on 23 May 2018.

Safety and Pharmacokinetics of the Aminomethylcycline Antibiotic Omadacycline Administered to Healthy Subjects in Oral Multiple-Dose Regimens.

Omadacycline, a first-in-class aminomethylcycline antibiotic, is related to tetracyclines but is structurally modified to circumvent mechanisms of resistance to tetracyclines. Omadacycline demonstrates potent activity against a broad range of pathogens, including drug-resistant strains, and is in late-stage development for treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. Previous studies support an intravenous-to-oral transition regimen with 300-mg once-daily oral dosing. This phase 1 study investigated the pharmacokinetics and safety/tolerability of multiple oral omadacycline doses higher than 300 mg. Using a 3-period crossover design, healthy adults were randomized to receive oral omadacycline at 300, 450, and 600 mg in variable sequence (n = 26) or placebo (n = 7) once daily for 5 consecutive days per period. In plasma, omadacycline maximum concentration and total exposure increased with increasing dose but were less than dose proportional. The kinetics of omadacycline plasma accumulation were similar between dose levels; exposure on day 5 was ∼50% higher than that on day 1. Omadacycline plasma concentrations on day 1 of 450-mg dosing were similar to those on day 5 of 300-mg dosing. All doses were generally well tolerated, but the 600-mg dose was associated with more gastrointestinal adverse events.

Data from Controlled Metabolic Ward Studies Provide Guidance for the Determination of Status Indicators and Dietary Requirements for Magnesium.

Determination of whether magnesium (Mg) is a nutrient of public health concern has been hindered by questionable Dietary Recommended Intakes (DRIs) and problematic status indicators that make Mg deficiency assessment formidable. Balance data obtained since 1997 indicate that the EAR and RDA for 70-kg healthy individuals are about 175 and 250 mg/day, respectively, and these DRIs decrease or increase based on body weight. These DRIs are less than those established for the USA and Canada. Urinary excretion data from tightly controlled metabolic unit balance studies indicate that urinary Mg excretion is 40 to 80 mg (1.65 to 3.29 mmol)/day when Mg intakes are <250 mg (10.28 mmol)/day, and 80 to 160 mg (3.29 to 6.58 mmol)/day when intakes are >250 mg (10.28 mmol)/day. However, changing from low to high urinary excretion with an increase in dietary intake occurs within a few days and vice versa. Thus, urinary Mg as a stand-alone status indicator would be most useful for population studies and not useful for individual status assessment. Tightly controlled metabolic unit depletion/repletion experiments indicate that serum Mg concentrations decrease only after a prolonged depletion if an individual has good Mg reserves. These experiments also found that, although individuals had serum Mg concentrations approaching 0.85 mmol/L (2.06 mg/dL), they had physiological changes that respond to Mg supplementation. Thus, metabolic unit findings suggest that individuals with serum Mg concentrations >0.75 mmol/L (1.82 mg/L), or as high as 0.85 mmol/L (2.06 mg/dL), could have a deficit in Mg such that they respond to Mg supplementation, especially if they have a dietary intake history showing <250 mg (10.28 mmol)/day and a urinary excretion of <80 mg (3.29 mmol)/day.

Association of brain-derived neurotrophic factor valine to methionine polymorphism with sexual dysfunction following selective serotonin reuptake inhibitor treatment in female patients with major depressive disorder.

INTRODUCTION: The occurrence of female sexual dysfunction (FSD) in patients with major depressive disorder (MDD) receiving selective serotonin reuptake inhibitors (SSRIs) treatment gives negative impacts on patients' quality of life and causes treatment discontinuation. We aimed to investigate whether genetic polymorphism of identified candidate gene is associated with FSD in our study population. METHODS: This is a cross-sectional study. A total of 95 female patients with MDD who met the criteria of the study were recruited and were specifically assessed on the sexual function by trained psychiatrists. Patients' DNA was genotyped for BDNF Val66Met polymorphism using real-time polymerase chain reaction. RESULTS: The prevalence of FSD in this study is 31.6%. In the FSD group, patients with problematic marriage were significantly more frequent compared with patients who did not have problematic marriage (P = 0.009). Significant association was detected in the lubrication domain with BDNF Val66Met polymorphism (P = 0.030) using additive genetic model, with even stronger association when using the recessive model (P = 0.013). DISCUSSION: This study suggested that there was no significant association between BDNF Val66Met with FSD. However, this polymorphism is significantly associated with lubrication disorder in patients treated with SSRIs.

Small Airway Dysfunction and Abnormal Exercise Responses. A Study in Coal Miners.

RATIONALE: Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. OBJECTIVES: We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. METHODS: Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. MEASUREMENTS AND MAIN RESULTS: Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. CONCLUSIONS: Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance.

Revisiting Nonresidential Environmental Exposures and Childhood Lead Poisoning in the US: Findings from Kansas, 2000-2005.

Although blood lead levels (BLLs) in US children have dramatically declined over the past 40 years, there remain pockets of children living in areas with elevated BLLs. While some increases (≥ 10 µg/dL) may be associated with legacy lead paint, ambient air lead may be contributing to the problem. A deidentified dataset of information on over 60,000 Kansas children under 3 years of age who were tested for BLL was provided through the Kansas Environmental Public Health Tracking Network for the period 2000-2005. Using ArcGIS, we calculated distance (in miles) from a lead-emitting industry referred to as a toxic release inventory (TRI) site. The USEPA TRI database tracks the management of certain toxic chemicals that may pose a threat to human health. US facilities in different industry sectors must report annually amount of substances like lead into the environment including their exact location. Distance from a TRI site was inversely related to BLL after controlling for area-level poverty and pre-1950 housing. The results of our evaluation indicate there is a significant relationship between proximity to lead industry and childhood BLLs. Proximity to sources of lead emissions should be evaluated as a possible factor when identifying children for targeted BLL testing.

Prevalence of Airflow Obstruction in U.S. Adults Aged 40-79 Years: NHANES Data 1988-1994 and 2007-2010.

BACKGROUND: The study evaluated the change in the prevalence of airflow obstruction in the U.S. population 40-79 years of age from years 1988-1994 to 2007-2010. METHODS: Spirometry data from two representative samples of the U.S. population, the National Health and Nutrition Examination Surveys (NHANES) conducted in 1988-1994 and 2007-2010, were used. The American Thoracic Society/European Respiratory Society (ATS/ERS) criteria were used to define airflow obstruction. RESULTS: Based on ATS/ERS criteria, the overall age-adjusted prevalence of airflow obstruction among adults aged 40-79 years decreased from 16.6% to 14.5% (p < 0.05). Significant decreases were observed for the older age category 60-69 years (20.2% vs. 15.4%; p < 0.01), for males (19.0% vs. 15.4%; p < 0.01), and for Mexican American adults (12.7% vs. 8.4%; p < 0.001). The prevalence of moderate and more severe airflow obstruction decreased also (6.4% vs. 4.4%; p < 0.01). Based on ATS/ERS criteria, during 2007-2010, an estimated 18.3 million U.S. adults 40-79 years had airflow obstruction, 5.6 million had moderate or severe airflow obstruction and 1.4 million had severe airflow obstruction. CONCLUSIONS: The overall age-adjusted prevalence of airflow obstruction among U.S. adults aged 40-79 years decreased from 1988-1994 to 2007-2010, especially among older adults, Mexican Americans, and males.

A case-crossover analysis of the impact of PM(2.5) on cardiovascular disease hospitalizations for selected CDC tracking states.

BACKGROUND: Information is currently being collected by the CDC Environmental Public Health Tracking (EPHT) network on hospitalizations due to Acute Myocardial Infarction (AMI) and there is interest by CDC in exploring the relationship between fine particulate matter (PM2.5) and other cardiovascular (CVD) outcomes in the context of the EPHT program. The goal of this study was to assess the short term effects of daily PM(2.5) air pollution levels on hospitalizations for CVD for seven states within the CDC EPHT network (Florida, Massachusetts, New Hampshire, New Jersey, New Mexico, New York, and Washington). METHODS: Hospitalization data was obtained for 2001-2008 admissions for circulatory disease (primary discharge diagnosis of ICD-9 codes 390-459) from data stewards in those states and included admission date, age, gender, and zip code of residence. We used CMAQ-derived predicted daily PM2.5 data as estimated by EPA at the centroid of each Census Bureau Zip Code Tabulation Area (ZCTA) and linked to zip code of patient residence. A time-stratified case-crossover study design with conditional logistic regression was used to evaluate the short-term association of PM2.5 on risk of non-elective hospitalizations for CVD. Specifically, we considered all circulatory disease, ischemic heart disease, acute myocardial infarction, heart failure, cardiac arrhythmia, cerebrovascular disease and peripheral vascular disease endpoints. RESULTS: Data were obtained on over 7,500,000 hospitalizations for this time period. Mean annual PM2.5 exposure levels were lowest for New Mexico and Washington (6.5 µg/m3 PM2.5 and 8.4 µg/m3 PM2.5). New Jersey, New York and Massachusetts exhibited the highest annual averages for PM2.5, (12.8 µg/m3, 11.1 µg/m3 and 10.8 µg/m3), respectively. The Northeast states (Massachusetts, New Jersey, New Hampshire and New York) exhibited significant effects of PM2.5 during the cooler months across most disease categories after adjustment for ozone and maximum apparent temperature. Ischemic heart disease risk per 10 µg/m3 increase in PM2.5 varied from 1.02 to 1.05 for the cooler months. The largest lag effect was noted on lag days 0 and 1. New Mexico and Washington exhibited no cool or warm month significant effects. Although Florida showed no cooler month effects, significant increases were noted in odds ratios for the warm weather months for all outcomes except peripheral vascular disease. This study is one of the first large scale applications of linkage of hospitalization data by state with national US EPA statistically modeled air pollution data. The results demonstrate that state-wide, there are multiple cardiovascular outcomes in addition to AMI which may be impacted by particulate air pollution.

Hypothermia and neonatal encephalopathy.

Data from large randomized clinical trials indicate that therapeutic hypothermia, using either selective head cooling or systemic cooling, is an effective therapy for neonatal encephalopathy. Infants selected for cooling must meet the criteria outlined in published clinical trials. The implementation of cooling needs to be performed at centers that have the capability to manage medically complex infants. Because the majority of infants who have neonatal encephalopathy are born at community hospitals, centers that perform cooling should work with their referring hospitals to implement education programs focused on increasing the awareness and identification of infants at risk for encephalopathy, and the initial clinical management of affected infants.

An intervention to improve transitions from NICU to ambulatory care: quasi-experimental study.

BACKGROUND: Infants born prematurely or with complex medical problems are surviving to discharge in growing numbers and often require significant monitoring and coordination of care in the ambulatory setting. Using Healthcare Failure Modes and Effects Analysis (HFMEA), we identified a large number of potentially serious error points in this transition of care. PURPOSE To test whether a multifaceted intervention that included a health coach to assist families and an enhanced personal health record to improve the quality of information available to parents and community professionals would decrease adverse events and improve family assessment of the transition. METHODS: Using a concurrent cohort design, infants in one geographic area (pod) of the intensive care nursery received the intervention; infants in two other pods received routine discharge care. Primary outcomes included deaths, sick visits, unplanned readmissions and missed appointments within 1 month of discharge. The family assessed the transition using a modified version of the Care Transitions Measure. RESULTS: 125 intervention infants (54% boys) and 104 control infants (48% boys) were enrolled over 18 months. The groups were similar in maternal education, insurance status, language spoken and number of adults in the home, birth weight and length of stay. At least one adverse outcome occurred in 63 (50.4%) intervention infants and 56 (53.8%) control infants (p=0.55). At 24­48 h post discharge, caregivers in the intervention group had significantly higher scores on the adapted care transitions measure (3.51 vs 3.27, p<0.0001); however, at 30 days, the difference was no longer significant (3.45 vs 3.40, p=0.27). CONCLUSIONS: A multicomponent discharge intervention designed to address specific problems identified using HFMEA did not reduce certain adverse outcomes in the post-discharge period. TRIAL REGISTRATION: NCT01088945.

Death or neurodevelopmental impairment at 18 to 22 months corrected age in a randomized trial of early dexamethasone to prevent death or chronic lung disease in extremely low birth weight infants.

OBJECTIVE: To evaluate the incidence of death or neurodevelopmental impairment (NDI) at 18-22 months corrected age in subjects enrolled in a trial of early dexamethasone treatment to prevent death or chronic lung disease in extremely low birth weight infants. STUDY DESIGN: Evaluation of infants at 18-22 months corrected age included anthropomorphic measurements, a standard neurological examination, and the Bayley Scales of Infant Development-II, including the Mental Developmental Index and the Psychomotor Developmental Index. NDI was defined as moderate or severe cerebral palsy, Mental Developmental Index or Psychomotor Developmental Index <70, blindness, or hearing impairment. RESULTS: Death or NDI at 18-22 months corrected age was similar in the dexamethasone and placebo groups (65% vs 66%, P = .99 among those with known outcome). The proportion of survivors with NDI was also similar, as were mean values for weight, length, and head circumference and the proportion of infants with poor growth (50% vs 41%, P = .42 for weight less than 10th percentile); 49% of infants in the placebo group received treatment with corticosteroid compared with 32% in the dexamethasone group (P = .02). CONCLUSION: The risk of death or NDI and rate of poor growth were high but similar in the dexamethasone and placebo groups. The lack of a discernible effect of early dexamethasone on neurodevelopmental outcome may be due to frequent clinical corticosteroid use in the placebo group.

Correlates of nonalcoholic fatty liver among women receiving residential mental health care.

PURPOSE: To review the risk factors for diagnosis of nonalcoholic fatty liver disease (NAFLD) in women in a mental health, dual diagnosis, treatment facility. DATA SOURCES: A review of the literature and retrospective chart reviews of patients to identify factors within this population of women most closely associated with diagnosis of NAFLD. CONCLUSIONS: NAFLD is a common diagnosis and as obesity rates increase in the United States the incidence for this disease is also increasing. Identifiable risk factors are associated with the presence of this disease. Advanced practice nurses, as prescribers, need to be aware that the presence of NAFLD may interfere with drug metabolism and toxin elimination in their patients. IMPLICATIONS FOR PRACTICE: Numerous physical conditions, behavioral symptoms, and laboratory findings are identified as associated conditions of NAFLD. Patients seen in primary care practices have NAFLD, but patients in treatment centers for mental health disorders are also affected. This population is particularly at risk because of the hepatotoxic effects of many medications used in psychiatric-mental health settings.

Lung-function impairment among US underground coal miners, 2005 to 2009: geographic patterns and association with coal workers' pneumoconiosis.

OBJECTIVE: To investigate contemporary geographic distributions of lung-function impairment and radiographic evidence of coal workers' pneumoconiosis (CWP) and their associations. METHODS: From 2005 to 2009, 6373 underground coal miners completed a health survey, including spirometry testing and chest radiography. Coal workers' pneumoconiosis and progressive massive fibrosis were determined by NIOSH B readers, using the International Labour Office classification. Prevalences of CWP and spirometry less than lower normal limits were mapped by county, and their association assessed. RESULTS: The prevalences of abnormal spirometry results and CWP were 13.1% and 4.0%, respectively. Counties with elevated prevalences for both the outcomes were located in contiguous areas of southeastern Kentucky, western Virginia, southern West Virginia, and eastern Pennsylvania. Prevalence of abnormal spirometry results increases with increasing category of simple CWP and progressive massive fibrosis. CONCLUSIONS: Abnormal spirometry in coal miners is associated with CWP; these two health outcomes have similar geographic distributions.

Rapid decline in lung function in coal miners: evidence of disease in small airways.

BACKGROUND: Coal mine dust exposure can cause both pneumoconiosis and chronic airflow limitation. The contributions of various pathophysiologic mechanisms to dust-related lung function decrements remain unclear. METHODS: Clinical and physiological findings were assessed for 15 underground coal miners who had demonstrated accelerated FEV1 losses (decliners) over 6-18 years. Decliners' findings were evaluated in comparison to a group of 11 miners who had shown relatively stable lung function (referents) during the same period. RESULTS: At follow-up examination, the decliners showed significantly greater mean airway resistance (10.47 vs. 6.78 cmH2 O/L/s; P = 0.05) and more air trapping (RV/TLC = 37.5 vs. 29.1%; P < 0.01) compared to the referents. Decliners also demonstrated more evidence of small airways dysfunction and tended to have more bronchospasm than the referent group. Total lung capacity, lung compliance, diffusing capacity, and chest radiography did not differ significantly between the two groups. After cessation of mine dust exposures, the decliners' mean rate of FEV1 loss normalized. CONCLUSION: In a series of working coal miners, accelerated lung function declines were associated with air trapping and evidence of small airways dysfunction. A preventive benefit from controlling dust exposures was suggested.