Short-term associations between air pollution and respiratory drug sales

Association between air pollution levels and drug sales for asthma and allergy in 63 million people in metropolitan France

INTRODUCTION

Air pollution is known to have an impact on respiratory health. However, the assessment of this relationship is far from complete and is rarely extended to the country level. We used drug sales data, both Over-The-Counter (OTC) and prescription drugs, to assess exhaustively the impact of air pollution on asthma and allergy at the national level in France.

METHODS

The WHO Anatomical Therapeutic Chemical (ATC) classification system was used to describe the distribution of sales of drugs of class R03 (Drugs for obstructive airways diseases, overall for asthma) and R06 (Antihistamines for systemic use). We performed a Quasi-Poisson regression model with a generalized additive model (GAM) to estimate the relationship (Relative Risks and 95% Confidence Interval) between drug sales and air pollutants, that is Particulate Matter with a diameter less than 2.5 micrometers (PM2.5) and less than 10 micrometers (PM10) and Nitrogen dioxide (NO2), as assessed using the high-resolution CHIMERE dispersion model. We designed unadjusted and adjusted single-pollutant models as well as two-pollutant models.

RESULTS

PM2.5, PM10, and NO2 were significantly and positively associated with sales of R03 and R06 class drugs, after adjustment for potential confounders. Results were confirmed in the two-pollutant model for PM10 and NO2 but not for PM2.5.

CONCLUSIONS

Our study confirms the presence of an association between major air pollutants and the sales of drugs against asthma and allergies. Further studies on larger databases and over several years are necessary to confirm and better understand these results.

Regional inequalities in benzene exposures across the European petrochemical industry: A Bayesian multilevel modelling approach

BACKGROUND

Pollutants released from the petrochemical industry are thought to increase the risk of mortality in fence-line communities, yet the results from previous studies are often inconsistent and lack a global perspective, hampered by the absence of cohesive cross-country research.

OBJECTIVES

To provide the first Pan-European analysis of benzene exposures from the petrochemical industry, connecting polluting practices to pollution episodes and disparities in regional mortality rates, identifying the measures of best environmental practice to mitigate adverse outcomes.

METHODS

The activity, classification and location of onshore petrochemical facilities within EU-28 Member States were extracted from the 'European Pollutant Release and Transfer Register' (E-PRTR), which holds records on 31,753 industrial operations for the reporting period of 2007-15. Parent company records were collected from the Moody's Analytics Amadeus database of 487,338 active companies across Europe. The EUROSTAT census provided records of income, life expectancy, and the underlying demographics used to calculate standardised health outcomes based on 9,936 sub-populations within the NUTS2 regions. The European Environment Agency provided ambient concentrations of benzene from 579 air quality stations. Bayesian multilevel models were constructed to account for variability caused by spatial hierarchical structures, uncertainty in the estimates, and to incorporate both individual and group-level influences.

RESULTS

Higher levels of benzene emissions from petrochemical operations, both overall and in terms of specific pollution events, were associated with increased mortality rates for nearby residential populations, particularly in areas with socioeconomic deprivation. We identify uneven patterns of polluting practices within the industry, and locations that require epidemiological studies.

CONCLUSIONS

While petrochemical facilities in all European Union regions are regulated to be compliant with the annual average benzene limit of 5 μg/m3, uneven exposures still present regional health inequalities. We recommend extending benzene regulations to an hourly or daily limit, alongside the strengthening of regulation for other toxic petrochemical releases.

A Review of Medication Use as an Indicator of Human Health Impact in Environmentally Stressed Areas

We reviewed from literature the feasibility of medication use as an indicator of health outcomes in environmentally stressed areas, especially where a paucity of typical epidemiological and other risk-based data are encountered. The majority of studies reported were about medication use as an indicator of adverse respiratory effects from air pollution in developed countries. Studies to a lesser extent pointed to medication use as indicator of health outcomes associated with other environmental health stressors such as water, noise pollution, and habitat conditions. The relationship between environmental stressors and medication use strongly suggests that medication use could be used to measure the impact of environmental stressors that otherwise could not be measured by epidemiological or other impact assessment studies, typically in settings where morbidity and mortality data might not be not accessible.

Wastewater-based epidemiological evaluation of the effect of air pollution on short-acting beta-agonist consumption for acute asthma treatment

Asthma, one of the most common chronic diseases in the world and a leading cause of hospitalization among children, has been associated with outdoor air pollution. We applied the wastewater-based epidemiology (WBE) approach to study the association between the use of salbutamol, a short-acting beta-agonist used to treat acute bronchospasm, and air pollution in the population of Milan, Italy. Composite 24-h samples of untreated wastewater were collected daily and analyzed for human metabolic residues of salbutamol by liquid chromatography tandem mass spectrometry. Corresponding daily outdoor concentrations of particular matter up to 10µm (PM10) and 2.5µm (PM2.5) in aerodynamic diameter, nitrogen dioxide, ozone, sulfur dioxide, and benzene were collected from the public air monitoring network. Associations at different lag times (0-10 days) were assessed by a log-linear Poisson regression model. We found significant direct associations between defined daily doses (DDD) of salbutamol and mean daily concentrations of PM10 and PM2.5 up to nine days of lag time. The highest rate ratio, and 95% confidence interval (CI), of DDD of salbutamol was 1.06 (95% CI: 1.02-1.10) and 1.07 (95% CI: 1.02-1.12) at seven days of lag time and for an increase of 10 μg/m(3) of PM10 and PM2.5, respectively. Reducing the mean daily PM10 concentration in Milan from 50 to 30μg/m(3) means that 852 (95% CI: 483-1504) daily doses of salbutamol per day would not be used. These results confirm the association between asthma and outdoor PM10 and PM2.5 and prove the potential of the WBE approach to quantitatively estimate the relation between environmental exposures and diseases.

Respiratory medication sales and urban air pollution in Brussels (2005 to 2011)

BACKGROUND

We investigated the associations between daily sales of respiratory medication and air pollutants in the Brussels-Capital Region between 2005 and 2011.

METHODS

We used over-dispersed Poisson Generalized Linear Models to regress daily individual reimbursement data of prescribed asthma and COPD medication from the social security database against each subject's residential exposure to outdoor particulate matter (PM10) or NO2 estimated, by interpolation from monitoring stations. We calculated cumulative risk ratios (RR) and their 95% confidence intervals (CI) for interquartile ranges (IQR) of exposure for different windows of past exposure for the entire population and for seven age groups.

RESULTS

Median daily concentrations of PM10 and NO2 were 25μg/m(3) (IQR=17.1) and 38μg/m(3) (IQR=20.5), respectively. PM10 was associated with daily medication sales among individuals aged 13 to 64y. For NO2, significant associations were observed among all age groups except >84y. The highest RR were observed for NO2, among adolescents, including three weeks lags (RR=1.187 95%CI: 1.097-1.285).

CONCLUSION

The associations found between temporal changes in exposure to air pollutants and daily sales of respiratory medication in Brussels indicate that urban air pollution contributes to asthma and COPD morbidity in the general population.

Direct cost saving potential in medication costs due to a reduction in outdoor air pollution for the Brussels Capital Region

INTRODUCTION

The adverse health effects of exposure to air pollution have been well-established and include mortality, hospital admissions, emergency department visits, etc, but also less severe outcomes such as medication use and purchase. The economic impact, an additional motivator for policy, has been studied primarily for the more severe outcomes.

METHODS

Purchase data of reimbursed medications typically prescribed for asthma and chronic obstructive pulmonary disease, were obtained through the mandatory Belgian health insurance system. A time series analyses approach was used to model daily sales on daily air pollution concentrations (NO2, PM10 and PM2.5) for residents of the Brussels Capital Region as a whole. In addition, a higher geographical resolution of both sales and pollutant concentrations allowed for a multi-sector approach. Annual savings were estimated for the scenario of a 10% reduction in each of the pollutants.

RESULTS

Medication purchase was significantly associated with NO2 concentrations, leading to an annual cost saving potential of € 107,845 [95%CI: € 71,483-€ 143,823] in R03 sales (WHO classification for drugs of obstructive airway diseases). Saving potentials of PM10 and PM2.5 were not significant. Estimates were not sensitive to the geographical resolution, however, higher precision can be obtained with higher resolution data, subject to the condition that the number of sales is sufficiently large.

Exploring the modeling of spatiotemporal variations in ambient air pollution within the land use regression framework: Estimation of PM10 concentrations on a daily basis

Estimation of daily average exposure to PM10 (particulate matter with an aerodynamic diameter<10 μm) using the available fixed-site monitoring stations (FSMs) in a city poses a great challenge. This is because typically FSMs are limited in number when considering the spatial representativeness of their measurements and also because statistical models of citywide exposure have yet to be explored in this context. This paper deals with the later aspect of this challenge and extends the widely used land use regression (LUR) approach to deal with temporal changes in air pollution and the influence of transboundary air pollution on short-term variations in PM10. Using the concept of multiple linear regression (MLR) modeling, the average daily concentrations of PM10 in two European cities, Vienna and Dublin, were modeled. Models were initially developed using the standard MLR approach in Vienna using the most recently available data. Efforts were subsequently made to (i) assess the stability of model predictions over time; (ii) explores the applicability of nonparametric regression (NPR) and artificial neural networks (ANNs) to deal with the nonlinearity of input variables. The predictive performance of the MLR models of the both cities was demonstrated to be stable over time and to produce similar results. However, NPR and ANN were found to have more improvement in the predictive performance in both cities. Using ANN produced the highest result, with daily PM10 exposure predicted at R2=66% for Vienna and 51% for Dublin. In addition, two new predictor variables were also assessed for the Dublin model. The variables representing transboundary air pollution and peak traffic count were found to account for 6.5% and 12.7% of the variation in average daily PM10 concentration. The variable representing transboundary air pollution that was derived from air mass history (from back-trajectory analysis) and population density has demonstrated a positive impact on model performance.

IMPLICATIONS

The implications of this research would suggest that it is possible to produce a model of ambient air quality on a citywide scale using the readily available data. Most European cities typically have a limited FSM network with average daily concentrations of air pollutants as well as available meteorological, traffic, and land-use data. This research highlights that using these data in combination with advanced statistical techniques such as NPR or ANNs will produce reasonably accurate predictions of ambient air quality across a city, including temporal variations. Therefore, this approach reduces the need for additional measurement data to supplement existing historical records and enables a lower-cost method of air pollution model development for practitioners and policy makers.

Association between respiratory prescribing, air pollution and deprivation, in primary health care

BACKGROUND

We investigated the association between respiratory prescribing, air quality and deprivation in primary health care. Most previous studies have used data from secondary and tertiary care to quantify air pollution effects on exacerbations of asthma and chronic obstructive pulmonary disease (COPD). However, these outcomes capture patients who suffer from relatively severe symptoms.

METHODS

This is a population-based ecological study. We analysed respiratory medication (salbutamol) prescribed monthly by 63 primary care practices, UK. Firstly, we captured the area-wide seasonal variation in prescribing. Then, using the area-wide variation in prescribing as an offset, we built a mixed-effects model to assess the remaining variation in relation to air quality and demographic variables.

RESULTS

An increase of 10 μg/m(3) in ambient PM10 was associated with an increase of 1% (95% CI: 0.1-2%) in salbutamol prescribing. An increase of 1 SD in income and employment deprivation was associated with an increase of 20.5% (95% CI: 8.8-33.4%) and 14.7% (95% CI: 4.3-26.2%) in salbutamol prescribing rate, respectively.

CONCLUSIONS

The study provides evidence that monthly respiratory prescribing in primary care is a useful indicator of the extent to which air pollution exacerbates asthma and COPD symptoms. Respiratory prescribing was higher on deprived populations.

Association of air pollution and use of glyceryl trinitrate against angina pectoris: a population-based case-crossover study

BACKGROUND

Ambient air pollution has been associated with increased cardiovascular morbidity and mortality. In Reykjavik, Iceland, air pollutant concentrations exceed official health limits several times every year. The aim was to study the association of concentrations of NO2, O3, PM10, and H2S in the Reykjavik capital area with the dispensing of anti-angina pectoris medication, glyceryl trinitrate to the inhabitants.

METHODS

Data on daily dispensing of glyceryl trinitrate, were retrieved from the Icelandic Medicines Registry. Data on hourly concentrations of NO2, O3, PM10, and H2S were obtained from the Environment Agency of Iceland. A case-crossover design was used, based on the dispensing of glyceryl trinitrate to 5,246 individuals (≥18 years) between 2005 and 2009.

RESULTS

For every 10 μg/m3 increase of NO2 and O3 3-day mean concentrations, the odds ratio (OR) for daily dispensing of glyceryl trinitrates was 1.136 (95% confidence intervals (CI) 1.069-1.207) and 1.094 (95% CI 1.029-1.163) at lag 0, and OR was 1.096 (95% CI 1.029-1.168) and 1.094 (95% CI 1.028-1.166) at lag 1, respectively.

CONCLUSIONS

These findings suggest that NO2 and O3 ambient air concentrations may adversely affect cardiovascular health, as measured by the dispensing of glyceryl trinitrates for angina pectoris. Further, the findings suggest that data on the dispensing of medication may be a valuable health indicator when studying the effect of air pollution on cardiovascular morbidity.

Measures of forest fire smoke exposure and their associations with respiratory health outcomes

PURPOSE OF REVIEW

Exposure to forest fire smoke is episodic, which makes its health effects challenging to study. We review the newest contributions to a growing literature on acute respiratory outcomes.

RECENT FINDINGS

Smoke exposure was associated with increases in self-reported symptoms, medication use, outpatient physician visits, emergency room visits, hospital admissions, and mortality. The associations were strongest for the outcomes most specific to asthma.

SUMMARY

Studies with varied approaches to exposure assessment and varied measures of respiratory outcomes were consistent among themselves, and consistent with most previous work.

Hydrogen sulfide and particle matter levels associated with increased dispensing of anti-asthma drugs in Iceland's capital

BACKGROUND

Air pollutants in Iceland's capital area include hydrogen sulfide (H2S) emissions from geothermal power plants, particle pollution (PM10) and traffic-related pollutants. Respiratory health effects of exposure to PM and traffic pollutants are well documented, yet this is one of the first studies to investigate short-term health effects of ambient H2S exposure.

OBJECTIVES

The aim of this study was to investigate the associations between daily ambient levels of H2S, PM10, nitrogen dioxide (NO2) and ozone (O3), and the use of drugs for obstructive pulmonary diseases in adults in Iceland's capital area.

METHODS

The study period was 8 March 2006 to 31 December 2009. We used log-linear Poisson generalized additive regression models with cubic splines to estimate relative risks of individually dispensed drugs by air pollution levels. A three-day moving average of the exposure variables gave the best fit to the data. Final models included significant covariates adjusting for climate and influenza epidemics, as well as time-dependent variables.

RESULTS

The three-day moving average of H2S and PM10 levels were positively associated with the number of individuals who were dispensed drugs at lag 3-5, corresponding to a 2.0% (95% confidence interval [CI] 0.4, 3.6) and 0.9% (95% CI 0.1, 1.8) per 10 μg/m3 pollutant concentration increase, respectively.

CONCLUSION

Our findings indicated that intermittent increases in levels of particle matter from traffic and natural sources and ambient H2S levels were weakly associated with increased dispensing of drugs for obstructive pulmonary disease in Iceland's capital area. These weak associations could be confounded by unevaluated variables hence further studies are needed.

Syndromic surveillance of acute gastroenteritis based on drug consumption

Since 1998, the French Health Insurance (NHI) system had established a national database in order to reimburse drug prescriptions. These electronical data are a considerable potential source for syndromic surveillance because of their exhaustive and regular updates. The aim of this study was to develop a method to identify acute gastroenteritis (AG) cases from drug reimbursements of the NHI database. The algorithm aimed at discriminating AG from other pathologies was determined from a sample of 206 AG prescriptions and 351 non-AG prescriptions collected in five pharmacies. The AG case identification was mainly based on the lag time between the prescription and delivery day, the occurrence of non-AG case-specific drugs, AG case-specific drug associations and treatment duration. The discriminant algorithm led to a sensitive and specific indicator of medically treated cases of AG with a time-spatial resolution power which met the need for waterborne AG surveillance.

Drug consumption and air pollution: an overview

PURPOSE

Acute respiratory symptoms are among the health effects of air pollution exposure. Studies over the past decades have linked respiratory drug use (consumption or sales) with changes in air pollution conditions.

METHODS

Twenty-one studies were analyzed to discuss whether increased levels of air pollution are associated with the use of medications for respiratory diseases.

RESULTS

Epidemiological studies agree that variation in the drug use is related to air pollution exposure. In panel studies, although asthmatics are more sensitive to air pollution effects, the increase in drug use was comparable and similar to non-asthmatics. Ecological studies confirm a significant association in respiratory drug sales depending on the selected lags (that is the time elapsing between air pollution measurement and the resulting drug use). The results of a meta-analysis of two ecological studies showed an increase in risk for increase in daily mean concentration of some pollutant (10 µg m(-3) ). For Black Smoke RR=1.007 (95% CI 1.004-1.011) for lag 1, and RR=1.008 (95% CI 1.005-1.010) for lag 8. For Nitrogen dioxide, RR=1.008 (95% CI 1.005-1.012) for lag 8 and for Sulfur dioxide, RR=1.005 (95% CI 1.001-1.010) for lag 9.

CONCLUSIONS

The analysis of drug use provides useful data for the evaluation of risks which derive from exposure to air pollution. More studies are needed to measure the effects of air pollution on respiratory medication use. Lags of up to 14 days have to be considered and the pollutants to be considered should include particulate matter and ozone.

Pharmacoepidemiological research using French reimbursement databases: yes we can!

PURPOSE

To describe the reimbursement databases available in France for pharmacoepidemiological research and their use.

METHODS

France has a publicly funded health system that systematically covers the population. Within this system, three main insurance schemes provide health services to citizens in France and each have their own reimbursement database. Together these three databases cover almost 97% of the French population (respectively for 54.5, 3.6, and 3.3 million individuals, and a total of 61.4 million individuals). Data in these concern patients, prescribers, all the medical acts reimbursed, prescription and undertaking of laboratory tests (but without results), private hospital data, partial public hospital data and vital status. Their use is regulated but access is free and the data are anonymous. PubMed and Scopus were searched for relevant studies published from January 1988 to June 2009.

RESULTS

110 published studies were included. The topics and the study characteristics were extremely wide-ranging. The studies assessed patterns of drug use, have tested interventions, supported or improved prescribing practices, tested compliance with the French governmental Health guidelines, assessed physicians' prescribing practices and performed economic and cost-effectiveness assessments. The number of articles published increased greatly between 2002 and 2003.

CONCLUSIONS

The French reimbursement databases were greatly used over the last 20 years. They can provide data on exposure to drugs and can be used to study patterns of drug utilization although their limitations must be considered.

Influence of socioeconomic deprivation on the relation between air pollution and beta-agonist sales for asthma

BACKGROUND

Air pollution triggers asthma attacks hours to days after exposure. It remains unclear whether socioeconomic deprivation modulates these effects. Investigation of these interactions requires adequate statistical power, obtainable by using either a sufficient number of observations or very sensitive indicators of asthma attacks. Using a small-area temporal ecologic approach, we studied the short-term relations between ambient air pollution and sales of short-acting beta-agonist (SABA) drugs, a frequent and specific treatment for control of asthma attacks in children and young adults, and then tested the influence of deprivation on these relations.

METHODS

The study took place in Strasbourg, France in 2004. Health insurance funds provided data on 15,121 SABA sales for patients aged 0 to 39 years. Deprivation was estimated by small geographic areas using an index constructed from census data. Daily average ambient concentrations of particulate matter (particles with an aerodynamic diameter < 10 microm [PM(10)]), nitrogen dioxide (NO(2)), and ozone (O(3)) were modeled on a small-area level. Adjusted case-crossover models were used for statistical analysis.

RESULTS

Increased of 10 microg/m(3) in ambient PM(10), NO(2), and O(3) concentrations were associated, respectively, with increases of 7.5% (95% confidence interval [CI], 4 to 11.2%), 8.4% (95% CI, 5 to 11.9%), and 1% (95% CI, - 0.3 to 2.2%) in SABA sales. Deprivation had no influence on these relations.

CONCLUSION

The associations observed are consistent with those reported by studies focusing on SABA use. Similar studies in other settings should confirm whether the lack of interaction with deprivation is due to specific local conditions.