Steven W. Howard

Long-Term Effects of Ambient PM2.5 on Hypertension and Blood Pressure and Attributable Risk Among Older Chinese Adults

Long-term exposure to ambient fine particulate pollution (PM2.5) has been associated with cardiovascular diseases. Hypertension, a major risk factor for cardiovascular diseases, has also been hypothesized to be linked to PM2.5. However, epidemiological evidence has been mixed. We examined long-term association between ambient PM2.5 and hypertension and blood pressure. We interviewed 12 665 participants aged 50 years and older and measured their blood pressures. Annual average PM2.5 concentrations were estimated for each community using satellite data. We applied 2-level logistic regression models to examine the associations and estimated hypertension burden attributable to ambient PM2.5. For each 10 &mgr;g/m3 increase in ambient PM2.5, the adjusted odds ratio of hypertension was 1.14 (95% confidence interval, 1.07–1.22). Stratified analyses found that overweight and obesity could enhance the association, and consumption of fruit was associated with lower risk. We further estimated that 11.75% (95% confidence interval, 5.82%–18.53%) of the hypertension cases (corresponding to 914, 95% confidence interval, 453–1442 cases) could be attributable to ambient PM2.5 in the study population. Findings suggest that long-term exposure to ambient PM2.5 might be an important risk factor of hypertension and is responsible for significant hypertension burden in adults in China. A higher consumption of fruit may mitigate, whereas overweight and obesity could enhance this effect.

Ambient PM 2.5 and Stroke : Effect Modifiers and Population Attributable Risk in Six Low- and Middle-Income Countries

Background and Purpose— Short-term exposure to ambient fine particulate pollution (PM2.5) has been linked to increased stroke. Few studies, however, have examined the effects of long-term exposure. Methods— A total of 45 625 participants were interviewed and included in this study, the participants came from the Study on Global Ageing and Adult Health, a prospective cohort in 6 low- and middle-income countries. Ambient PM2.5 levels were estimated for participants’ communities using satellite data. A multilevel logistic regression model was used to examine the association between long-term PM2.5 exposure and stroke. Potential effect modification by physical activity and consumption of fruit and vegetables was assessed. Results— The odds of stroke were 1.13 (95% confidence interval, 1.04–1.22) for each 10 &mgr;g/m3 increase in PM2.5. This effect remained after adjustment for confounding factors including age, sex, smoking, and indoor air pollution (adjusted odds ratio=1.12; 95% confidence interval, 1.04–1.21). Further stratified analyses suggested that participants with higher levels of physical activity had greater odds of stroke, whereas those with higher consumption of fruit and vegetables had lower odds of stroke. These effects remained robust in sensitivity analyses. We further estimated that 6.55% (95% confidence interval, 1.97%–12.01%) of the stroke cases could be attributable to ambient PM2.5 in the study population. Conclusions— This study suggests that ambient PM2.5 may increase the risk of stroke and may be responsible for the astounding stroke burden in low- and middle-income countries. In addition, greater physical activity may enhance, whereas greater consumption of fruit and vegetables may mitigate the effect.

Oregon's Experiment in Health Care Delivery and Payment Reform: Coordinated Care Organizations Replacing Managed Care

To control Medicaid costs, improve quality, and drive community engagement, the Oregon Health Authority introduced a new system of coordinated care organizations (CCOs). While CCOs resemble traditional Medicaid managed care, they have differences that have been deliberately designed to improve care coordination, increase accountability, and incorporate greater community governance. Reforms include global budgets integrating medical, behavioral, and oral health care and public health functions; risk-adjusted payments rewarding outcomes and evidence-based practice; increased transparency; and greater community engagement. The CCO model faces several implementation challenges. If successful, it will provide improved health care delivery, better health outcomes, and overall savings.

Global association between ambient air pollution and blood pressure: A systematic review and meta-analysis

Although numerous studies have investigated the association of ambient air pollution with hypertension and blood pressure (BP), the results were inconsistent. We performed a comprehensive systematic review and meta-analysis of these studies. Seven international and Chinese databases were searched for studies examining the associations of particulate (diameter<2.5 μm (PM2.5), 2.5-10 μm (PM2.5-10) or >10 μm (PM10)) and gaseous (sulfur dioxide (SO2), nitrogen dioxide (NO2), nitrogen oxides (NOx), ozone (O3), carbon monoxide (CO)) air pollutants with hypertension or BP. Odds ratios (OR), regression coefficients (β) and their 95% confidence intervals were calculated to evaluate the strength of the associations. Subgroup analysis, sensitivity analysis, and meta-regression analysis were also conducted. The overall meta-analysis showed significant associations of long-term exposures to PM2.5 with hypertension (OR = 1.05), and of PM10, PM2.5, and NO2 with DBP (β values: 0.47-0.86 mmHg). In addition, short-term exposures to four (PM10, PM2.5, SO2, NO2), two (PM2.5 and SO2), and four air pollutants (PM10, PM2.5, SO2, and NO2), were significantly associated with hypertension (ORs: 1.05-1.10), SBP (β values: 0.53-0.75 mmHg) and DBP (β values: 0.15-0.64 mmHg), respectively. Stratified analyses showed a generally stronger relationship among studies of men, Asians, North Americans, and areas with higher air pollutant levels. In conclusion, our study indicates a positive association between ambient air pollution and increased BP and hypertension. Geographical and socio-demographic factors may modify the pro-hypertensive effects of air pollutants.

Use Your Words Carefully: What Is a Chronic Disease?

One important element of effective communication is having a shared language or at least a shared understanding of the meaning of the central words used in a conversation. One term that is often used in discussions between patients and medical providers, in the academic literature, and in policy discussions, is “chronic disease.” There is not only tremendous variation in the diseases that are included under the umbrella term “chronic disease” but also variation in the time a disease must be present for something to be referred to as chronic. Furthermore, there is a move to include chronic conditions that are not indicators of disease, but long-standing functional disabilities, including developmental disorders and visual impairment (1–4). Within professional communities (i.e., medical, public health, academic, and policy), there is a large degree of variation in the use of the term chronic disease. For example, the Centers for Disease Control (CDC) classify the following as chronic diseases: heart disease, stroke, cancer, type 2 diabetes, obesity, and arthritis (5). The Centers for Medicare and Medicaid Services have a more extensive list of 19 chronic conditions that includes Alzheimer’s disease, depression, and HIV, to name a few. This difference, within the Department of Health and Human Services alone, although not surprising to those in the field, has the potential to create confusion and misunderstanding when speaking in generalities about the impact of chronic disease, the cost of chronic disease, and overall measures to reduce chronic disease. The academic literature is not immune to the same kind of terminology variation. Differences in how “chronic disease” is used are largely dependent on the data used for the research and the discipline of the lead authors (i.e., public health and sociology). For example, one study, authored by individuals from Harvard Medical School, explored the prevalence of chronic disease using NHANES data (1999–2004). The study classifies the following as chronic diseases: cardiovascular disease, hypertension, diabetes mellitus, hypercholesterolemia, asthma, COPD, and previous cancer (6). Another academic study on chronic disease, authored by a geriatrician, classifies chronic illness as “conditions that last a year or more and require ongoing medical attention and/or limit activities of daily living” (7). The implication of a non-uniform use of the term is that a detailed read of each study is necessary to avoid erroneous conclusions regarding interventions necessary to reduce chronic disease burden for the individual and society. Popular Internet sources used by the general public to gather medical information use the terms “chronic disease” or “chronic condition” to mean slightly different things. For example, MedicineNet describes a chronic disease as,

Oregon's Coordinated Care Organizations: A Promising and Practical Reform Model

Continuing its path of Medicaid program innovation, Oregon recently embarked on a major reform that gives regional coordinated care organizations (CCOs) global budgets and accountability for the physical, behavioral, and dental care of the states Medicaid beneficiaries (Howard et al. 2014). There are some who maintain that the states bold reform initiative is overly aggressive in scope and unrealistically optimistic in schedule and may prove to be a costly debacle to the state of Oregon. We argue that the Oregon CCO model is not only bold in its aims and timetable but also realistically achievable.

Flipping Classrooms in a School of Public Health

Alternative course formats are gaining increasing attention in higher education. The literature provides a number of examples and studies of flipped classrooms in the medical sciences and liberal arts and sciences. However, fewer than five papers on flipped classes in graduate public health courses have been published, and none in health management. Because graduate public health education is competency based, it seems that a flipped approach with its applied nature would be an appropriate form of teaching public health courses. This paper describes three successfully flipped courses taught in a school of public health. We provide a rationale for flipping, description of each course, and lessons learned. Once some of the challenges are overcome, we believe flipping courses can provide an alternative approach that enhances active learning in applied, public health, and health management courses.

Consumption of fruit and vegetables might mitigate the adverse effects of ambient PM2.5 on lung function among adults

Background Evidence on the effects of ambient PM2.5 on lung function is limited among adults and the effect modification by dietary fruit and vegetables remains largely unknown. Methods We interviewed 29,032 participants aged 50 years and older from the WHO Study on global AGEing and adult health. Annual average PM2.5 levels were estimated for each community using satellite data. We applied multi‐level linear regressions to examine the association between ambient PM2.5 and lung function (forced vital capacity (FVC), forced expiratory volume in 1‐sec (FEV1), FEV1/FVC ratio, peak expiratory flow (PEF), and forced expiratory flow between 25th and 75th percentiles of FVC (FEF25–75)). Results We found that ambient PM2.5 was associated with lower lung functions. Each 10 &mgr;g/m3 increase in PM2.5 corresponded to reductions of 123.58 ml in FVC (95% CI: −185.21, −61.95), 126.64 ml in FEV1 (95% CI: −186.04, −67.23) and 178.93 ml/s FEV25–75 (95% CI: −249.20, −108.66). Lower effect estimates were observed among those with higher consumption of fruit and vegetables. Conclusion Our study suggests that exposure to ambient PM2.5 might be one risk factor of reduced lung function in adults and that higher consumption of fruit and vegetables may mitigate this effect. HighlightsWe examined the effects of PM2.5 on lung function among adults.PM2.5 was associated with lower levels of FVC, FEV1 and FEV25‐75.Fruit and vegetables could mitigate these effects.

The attributable risk of chronic obstructive pulmonary disease due to ambient fine particulate pollution among older adults

BACKGROUND The linkage between ambient fine particle pollution (PM2.5) and chronic obstructive pulmonary disease (COPD) and the attributable risk remained largely unknown. This study determined the cross-sectional association between ambient PM2.5 and prevalence of COPD among adults ≥50 years of age. METHODS We surveyed 29,290 participants aged 50 years and above in this study. The annual average concentrations of PM2.5 derived from satellite data were used as the exposure indicator. A mixed effect model was applied to determine the associations and the burden of COPD attributable to PM2.5. RESULTS: Among the participants, 1872 (6.39%) were classified as COPD cases. Our analysis observed a threshold concentration of 30 μg/m3 in the PM2.5-COPD association, above which we found a linear positive exposure-response association between ambient PM2.5 and COPD. The odds ratio (OR) for each 10 μg/m3 increase in ambient PM2.5 was 1.21(95% CI: 1.13, 1.30). Stratified analyses suggested that males, older subjects (65 years and older) and those with lower education attainment might be the vulnerable subpopulations. We further estimated that about 13.79% (95% CI: 7.82%, 21.62%) of the COPD cases could be attributable to PM2.5 levels higher than 30 μg/m3 in the study population. CONCLUSION Our analysis indicates that ambient PM2.5 exposure could increase the risk of COPD and accounts for a substantial fraction of COPD among the study population.

Association of perfluoroalkyl substances exposure with impaired lung function in children.

&NA; Previous studies have demonstrated associations between serum levels of perfluoroalkyl substances (PFASs) and asthma or asthma related‐biomarkers. However, no studies have reported a possible relationship between PFASs exposure and lung function among children. The objective of the present study is to test the association between PFASs exposure and lung function in children from a high exposure area by using a cross‐sectional case‐control study, which included 132 asthmatic children and 168 non‐asthmatic controls recruited from 2009 to 2010 in the Genetic and Biomarkers study for Childhood Asthma. Structured questionnaires were administered face‐to‐face. Lung function was measured by spirometry. Linear regression models were used to examine the influence of PFASs on lung function. The results showed that asthmatics in our study had significantly higher serum PFAS concentrations than healthy controls. Logistic regression models showed a positive association between PFASs and asthma, with adjusted odds ratios (ORs) ranging from 0.99 (95% confidence interval [CI]: 0.80–1.21) to 2.76 (95% CI: 1.82–4.17). Linear regression modeling showed serum PFASs levels were significantly negatively associated with three pulmonary function measurements (forced vital capacity: FVC; forced expiratory volume in 1 s: FEV1; forced expiratory flow 25–75%: FEF25–75) among children with asthma, the adjusted coefficients between lung function and PFASs exposure ranged from −0.055 (95%CI: −0.100 to −0.010) for FVC and perfluorooctane sulfonate (PFOS) to −0.223 (95%CI: −0.400 to −0.045) for FEF25–75 and perfluorooctanoic acid (PFOA). PFASs were not, however, significantly associated with pulmonary function among children without asthma. In conclusion, this study suggests that serum PFASs are associated with decreased lung function among children with asthma. HighlightsLittle research exists on the relationship between PFASs exposure and lung function.Association of serum PFASs with lung function was assessed in high exposure children.PFASs were positively associated with impaired lung function in children.The association was significant only in asthmatic children.