Parental beliefs and willingness to pay for reduction in their child's asthma symptoms: A joint estimation approach.

Many aspects of asthma-in particular the relationship between beliefs, averting behaviors, and symptoms-are not directly observable from market data. An approach that combines observable market data with nonmarket valuation to gather data on unobservable aspects of the illness can improve efforts to quantify the burden of asthma if it accounts for the endogeneity in the system. Such approaches are used in the valuation of recreation but have not been widely used to value the burden of a chronic illness. We estimate parents' willingness to pay (WTP) to reduce their child's asthma symptoms using a three-equation model that combines revealed preference, contingent valuation, and burden of asthma, increasing the efficiency of estimation and correcting for endogeneity. WTP for a device that reduces a child's asthma symptoms by 50% is $125/month (s.d. $20). Parents' valuations are driven by beliefs about asthma and by their degree of worry about asthma between episodes. There is a nonlinear relationship between the number of days with symptoms and WTP per symptom day. The experience of living with asthma affects families' responses to a contingent valuation scenario, because it influences willingness to spend money to manage the illness and their subjective perceptions and beliefs about the illness itself.

A Step-by-Step Guide to Building a Complex Care Coordination Program in a Small Setting.

Children with medical complexity comprise a growing population that stresses existing models of pediatric care. This report will describe a care support project that delivered shared plans of care to providers and families of children with medical complexity. This program was built around carefully constructed care support teams where each member had clearly defined roles and responsibilities. The teams worked collaboratively to improve provider communication, create SMART (Specific, Measurable, Assignable, Realistic, and Timely) goals, and perform task tracking. This process created a scaffolding to support community physicians, allowing patients to remain in their local medical homes and to access services closer to home and reducing hospital admissions and emergency room overutilization.

Optimizing community-level surveillance data for pediatric asthma management.

Community-level approaches for pediatric asthma management rely on locally collected information derived primarily from two sources: claims records and school-based surveys. We combined claims and school-based surveillance data, and examined the asthma-related risk patterns among adolescent students. Symptom data collected from school-based asthma surveys conducted in Oakland, CA were used for case identification and determination of severity levels for students (high and low). Survey data were matched to Medicaid claims data for all asthma-related health care encounters for the year prior to the survey. We then employed recursive partitioning to develop classification trees that identified patterns of demographics and healthcare utilization associated with severity. A total of 561 students had complete matched data; 86.1% were classified as high-severity, and 13.9% as low-severity asthma. The classification tree consisted of eight subsets: three indicating high severity and five indicating low severity. The risk subsets highlighted varying combinations of non-specific demographic and socioeconomic predictors of asthma prevalence, morbidity and severity. For example, the subset with the highest class-prior probability (92.1%) predicted high-severity asthma and consisted of students without prescribed rescue medication, but with at least one in-clinic nebulizer treatment. The predictive accuracy of the tree-based model was approximately 66.7%, with an estimated 91.1% of high-severity cases and 42.3% of low-severity cases correctly predicted. Our analysis draws on the strengths of two complementary datasets to provide community-level information on children with asthma, and demonstrates the utility of recursive partitioning methods to explore a combination of features that convey asthma severity.

Costs of coronary heart disease and mortality associated with near-roadway air pollution.

BACKGROUND: Emerging evidence indicates that the near-roadway air pollution (NRAP) mixture contributes to CHD, yet few studies have evaluated the associated costs. OBJECTIVE: We integrated an assessment of NRAP-attributable CHD in Southern California with new methods to value the associated mortality and hospitalizations. METHODS: Based on population-weighted residential exposure to NRAP (traffic density, proximity to a major roadway and elemental carbon), we estimated the inflation-adjusted value of NRAP-attributable mortality and costs of hospitalizations that occurred in 2008. We also estimated anticipated costs in 2035 based on projected changes in population and in NRAP exposure associated with California's plans to reduce greenhouse gas emissions. For comparison, we estimated the value of CHD mortality attributable to PM less than 2.5µm in diameter (PM2.5) in both 2008 and 2035. RESULTS: The value of CHD mortality attributable to NRAP in 2008 was between $3.8 and $11.5 billion, 23% (major roadway proximity) to 68% (traffic density) of the $16.8 billion attributable to regulated regional PM2.5. NRAP-attributable costs were projected to increase to $10.6 to $22 billion in 2035, depending on the NRAP metric. Cost of NRAP-attributable hospitalizations for CHD in 2008 was $48.6 million and was projected to increase to $51.4 million in 2035. CONCLUSIONS: We developed an economic framework that can be used to estimate the benefits of regulations to improve air quality. CHD attributable to NRAP has a large economic impact that is expected to increase by 2035, largely due to an aging population. PM2.5-attributable costs may underestimate total value of air pollution-attributable CHD.

Near-Roadway Air Pollution and Coronary Heart Disease: Burden of Disease and Potential Impact of a Greenhouse Gas Reduction Strategy in Southern California.

BACKGROUND: Several studies have estimated the burden of coronary heart disease (CHD) mortality from ambient regional particulate matter ≤ 2.5 µm (PM2.5). The burden of near-roadway air pollution (NRAP) generally has not been examined, despite evidence of a causal link with CHD. OBJECTIVE: We investigated the CHD burden from NRAP and compared it with the PM2.5 burden in the California South Coast Air Basin for 2008 and under a compact urban growth greenhouse gas reduction scenario for 2035. METHODS: We estimated the population attributable fraction and number of CHD events attributable to residential traffic density, proximity to a major road, elemental carbon (EC), and PM2.5 compared with the expected disease burden if the population were exposed to background levels of air pollution. RESULTS: In 2008, an estimated 1,300 CHD deaths (6.8% of the total) were attributable to traffic density, 430 deaths (2.4%) to residential proximity to a major road, and 690 (3.7%) to EC. There were 1,900 deaths (10.4%) attributable to PM2.5. Although reduced exposures in 2035 should result in smaller fractions of CHD attributable to traffic density, EC, and PM2.5, the numbers of estimated deaths attributable to each of these exposures are anticipated to increase to 2,500, 900, and 2,900, respectively, due to population aging. A similar pattern of increasing NRAP-attributable CHD hospitalizations was estimated to occur between 2008 and 2035. CONCLUSION: These results suggest that a large burden of preventable CHD mortality is attributable to NRAP and is likely to increase even with decreasing exposure by 2035 due to vulnerability of an aging population. Greenhouse gas reduction strategies developed to mitigate climate change offer unexploited opportunities for air pollution health co-benefits.

Cost of near-roadway and regional air pollution-attributable childhood asthma in Los Angeles County.

BACKGROUND: Emerging evidence suggests that near-roadway air pollution (NRP) exposure causes childhood asthma. The associated costs are not well documented. OBJECTIVE: We estimated the cost of childhood asthma attributable to residential NRP exposure and regional ozone (O3) and nitrogen dioxide (NO2) levels in Los Angeles County. We developed a novel approach to apportion the costs between these exposures under different pollution scenarios. METHODS: We integrated results from a study of willingness to pay to reduce the burden of asthma with results from studies of health care use and charges to estimate the costs of an asthma case and exacerbation. We applied those costs to the number of asthma cases and exacerbations caused by regional pollution in 2007 and to hypothetical scenarios of a 20% reduction in regional pollution in combination with a 20% reduction or increase in the proportion of the total population living within 75 m of a major roadway. RESULTS: Cost of air pollution-related asthma in Los Angeles County in 2007 was $441 million for O3 and $202 million for NO2 in 2010 dollars. Cost of routine care (care in absence of exacerbation) accounted for 18% of the combined NRP and O3 cost and 39% of the combined NRP and NO2 cost; these costs were not recognized in previous analyses. NRP-attributable asthma accounted for 43% (O3) to 51% (NO2) of the total annual cost of exacerbations and routine care associated with pollution. Hypothetical scenarios showed that costs from increased NRP exposure might offset savings from reduced regional pollution. CONCLUSIONS: Our model disaggregates the costs of regional pollution and NRP exposure and illustrates how they might vary under alternative exposure scenarios. The cost of air pollution is a substantial burden on families and an economic loss for society.

Examining household asthma management behavior through a microeconomic framework.

National guidelines on the effective management of pediatric asthma have been promoted for over 20 years, yet asthma-related morbidity among low-income children remains disproportionately high. To date, household and clinical interventions designed to remediate these differences have been informed largely by a health behavior framework. However, these programs have not resulted in consistent sustained improvements in targeted populations. The continued funding and implementation of programs based on the health behavior framework leads us to question if traditional behavioral models are sufficient to understand and promote adaptation of positive health management behaviors. We introduce the application of the microeconomic framework to investigate potential mechanisms that can lead to positive management behaviors to improve asthma-related morbidity. We provide examples from the literature on health production, preferences, trade-offs and time horizons to illustrate how economic constructs can potentially add to understanding of disease management. The economic framework, which can be empirically observed, tested, and quantified, can explicate the engagement in household-level activities that would affect health and well-being. The inclusion of a microeconomic perspective in intervention research may lead to identification of mechanisms that lead to household decisions with regard to asthma management strategies and behavior. The inclusion of the microeconomic framework to understand the production of health may provide a novel theoretical framework to investigate the underlying causal behavioral mechanisms related to asthma management and control. Adaptation of an economic perspective may provide new insight into the design and implementation of interventions to improve asthma-related morbidity in susceptible populations.

Time and risk preferences and the use of asthma controller medication.

OBJECTIVES: We investigated the role of risk tolerance, time preference, and asthma-specific attitudes in adherence to asthma control medications. METHODS: Students with persistent asthma completed an online survey on asthma beliefs, risk tolerance, and time preference (n = 47). The time preference questions measure the degree to which the individual discounts future outcomes and essentially prefers immediate gratification to delayed gratification. The risk tolerance questions indicate the individual's dislike of uncertainty about outcomes. We analyzed the relationship between the independent and dependent variables. RESULTS: Feelings of embarrassment and concern about medication, as well as risk tolerance and time preference, were found to be significant predictors of adherence to control medication in the logistic regression. Analysis of probabilities associated with different profiles shows that at high rates of risk tolerance and discounting of future outcomes, the probability of adherence is near 0 regardless of asthma-specific attitudes. Asthma attitudes have a statistically significant effect for individuals with low rates of risk tolerance and time preference. CONCLUSIONS: The risk tolerance and time preferences of the target group should be considered when designing an asthma-intervention program. Individuals who strongly prefer immediate gratification over future benefits and are willing to tolerate uncertain outcomes are unlikely to adhere to controller medication, regardless of their asthma attitudes. In contrast, efforts to affect relevant attitudes will be most fruitful for individuals with low rates of risk tolerance and time preference. However, as we cannot extrapolate these results to a larger population, we must view them with caution.

Contingent valuation scenarios for chronic illnesses: the case of childhood asthma.

OBJECTIVES: We use a contingent valuation (CV) study of childhood asthma to discuss a central issue in designing CV studies of chronic illness-the need for a detailed, realistic scenario that minimizes confounding factors-and show how to address this issue. We apply our methodology to estimate households' willingness to pay (WTP) for reductions in asthma morbidity. METHODS: By using a combination of focus groups, revealed preference surveys, and epidemiological surveys, we gathered information on health status, attitudes, and beliefs regarding asthma, risk-averting behaviors, perceptions of these behaviors, and household socioeconomic characteristics. We used this information to design a CV survey that we extensively tested for validity. In the survey, we elicited participants' WTP for a hypothetical device that would reduce symptom-days by improving asthma management; these data enabled us to estimate household WTP by using a variety of econometric models. RESULTS: Our analysis of households with children with asthma yielded the following conclusions: the scenario should address both physical asthma symptoms and the psychosocial stress of managing a chronic illness; the survey should measure household perceptions of the burden of asthma in addition to objective measures such as symptom-days; and the scenario should not involve substantial behavioral changes or a new medication, to avoid confounding household preferences with unrelated attributes of the scenario. Our primary models estimated mean household WTP for a 50% reduction in symptom-days (and accompanying reductions in psychosocial stress) at $56.48 to $64.84 per month. CONCLUSIONS: Our methodology can be used to inform CV studies of chronic illness. Our WTP estimates can help regulatory agencies assess a wide range of policies that affect the incidence or severity of asthma.

Near-roadway pollution and childhood asthma: implications for developing "win-win" compact urban development and clean vehicle strategies.

BACKGROUND: The emerging consensus that exposure to near-roadway traffic-related pollution causes asthma has implications for compact urban development policies designed to reduce driving and greenhouse gases. OBJECTIVES: We estimated the current burden of childhood asthma-related disease attributable to near-roadway and regional air pollution in Los Angeles County (LAC) and the potential health impact of regional pollution reduction associated with changes in population along major traffic corridors. METHODS: The burden of asthma attributable to the dual effects of near-roadway and regional air pollution was estimated, using nitrogen dioxide and ozone as markers of urban combustion-related and secondary oxidant pollution, respectively. We also estimated the impact of alternative scenarios that assumed a 20% reduction in regional pollution in combination with a 3.6% reduction or 3.6% increase in the proportion of the total population living near major roads, a proxy for near-roadway exposure. RESULTS: We estimated that 27,100 cases of childhood asthma (8% of total) in LAC were at least partly attributable to pollution associated with residential location within 75 m of a major road. As a result, a substantial proportion of asthma-related morbidity is a consequence of near-roadway pollution, even if symptoms are triggered by other factors. Benefits resulting from a 20% regional pollution reduction varied markedly depending on the associated change in near-roadway proximity. CONCLUSIONS: Our findings suggest that there are large and previously unappreciated public health consequences of air pollution in LAC and probably in other metropolitan areas with dense traffic corridors. To maximize health benefits, compact urban development strategies should be coupled with policies to reduce near-roadway pollution exposure.

Costs of childhood asthma due to traffic-related pollution in two California communities.

Recent research suggests the burden of childhood asthma that is attributable to air pollution has been underestimated in traditional risk assessments, and there are no estimates of these associated costs. We aimed to estimate the yearly childhood asthma-related costs attributable to air pollution for Riverside and Long Beach, CA, USA, including: 1) the indirect and direct costs of healthcare utilisation due to asthma exacerbations linked with traffic-related pollution (TRP); and 2) the costs of health care for asthma cases attributable to local TRP exposure. We calculated costs using estimates from peer-reviewed literature and the authors' analysis of surveys (Medical Expenditure Panel Survey, California Health Interview Survey, National Household Travel Survey, and Health Care Utilization Project). A lower-bound estimate of the asthma burden attributable to air pollution was US$18 million yearly. Asthma cases attributable to TRP exposure accounted for almost half of this cost. The cost of bronchitic episodes was a major proportion of both the annual cost of asthma cases attributable to TRP and of pollution-linked exacerbations. Traditional risk assessment methods underestimate both the burden of disease and cost of asthma associated with air pollution, and these costs are borne disproportionately by communities with higher than average TRP.

Estimated effect of asthma case management using propensity score methods.

OBJECTIVE: To estimate the treatment effect of participation in an asthma intervention that was part of the National Asthma Control Program. STUDY DESIGN: Cross-sectional; difference in outcomes between participants and comparable nonparticipants matched by using propensity scores. METHODS: Data on children who participated in asthma case management (n = 270) and eligible children who did not participate in case management (n = 2742) were extracted from a Medicaid claims database. We constructed measures of healthcare utilization, sociodemographics, and neighborhood characteristics. After creating a comparison group similar to the participants in terms of all characteristics before participation, we estimated the effect of the program on asthma outcomes. RESULTS: Participants were more likely to have vaccinations for pulmonary illness (95% confidence interval [CI] = 1.82, 4.81), to fill a prescription for controller medications (95% CI = 1.07, 2.19), and to have a refill for rescue medication (95% CI = 1.07, 2.07) after the program than comparable nonparticipants. There was no statistically significant difference in the number of nebulizer treatments or emergency department visits between the 2 groups. CONCLUSIONS: The program did increase the use of preventive healthcare by participants. Over the time period we studied, these behaviors did not decrease healthcare utilization for asthma exacerbations. We were unable to discern whether the lack of effect was because of the nature of the program, heterogeneity of the effects, or barriers outside the program's control.

An analysis of predictors of sustainability efforts at the Inner-City Asthma Intervention sites: after the funding is gone.

BACKGROUND: The Inner-City Asthma Intervention was a national, multicenter implementation of an evidence-based intervention to reduce asthma morbidity in inner-city children that was funded by the Centers for Disease Control and Prevention. Funding was initially planned for 4 years beginning in April 2001, but because of budgetary changes funding ceased in September 2004, 6 months before the original plan. Some sites were able to sustain their asthma program when the funding ended and others were not. OBJECTIVE: To compare characteristics of sites that were able to sustain their asthma program after the original funding ended with those that were not. METHODS: Data were collected from the project manager at each site in an electronic survey and through telephone interview in November 2003 and August 2005. Using contingency tables, we examined the bivariate relationship between each proposed factor and our outcome measure, secured funding. RESULTS: Of the 18 sites that completed the survey, 50% reported continued funding. All sustainable sites received funding from multiple sources, including either the hospital or the community. One site received federal funding and one site received state funding. Of the sites that presented data to multiple funders, 6 of 9 were sustained (P = .05). CONCLUSIONS: Sustainable programs were more likely to be funded locally. Programs that used an evaluative process, including patient outcomes data, to demonstrate the importance of the program to their institution and community were more likely to obtain continued funding compared with those that did not.

Disparities in asthma hospitalization in Massachusetts.

OBJECTIVES: We examined racial disparities in asthma morbidity in Massachusetts. METHODS: We used Massachusetts case-mix data from 1994 to 2002 to screen and track individual asthma morbidity and hospitalizations, which resulted in a sample of 10145 patients who were first hospitalized for asthma between 1997 and 2000. We followed these patients for 2 years after their first hospitalization. Because asthma is widely considered a preventable cause of hospitalization, we interpreted a readmission for asthma as an indication of failed asthma management. RESULTS: We found substantial racial/ethnic disparities in readmission rates that persisted after control for comorbidities, payer type, and income. We estimated that the costs of repeat hospitalizations for asthma are in excess of one quarter of all asthma hospitalization costs. CONCLUSION: Racial/ethnic disparities in asthma readmission rates show that Massachusetts is not on the frontier of asthma treatment.