Social disparities in unplanned 30-day readmission rates after hospital discharge in patients with chronic health conditions: A retrospective cohort study using patient level hospital administrative data linked to the population census in Switzerland.

Unplanned readmissions shortly after discharge from hospital are common in chronic diseases. The risk of readmission has been shown to be related both to hospital care, e.g., medical complications, and to patients' resources and abilities to manage the chronic disease at home and to make appropriate use of outpatient medical care. Despite a growing body of evidence on social determinants of health and health behaviour, little is known about the impact of social and contextual factors on readmission rates. The objective of this study was to analyse possible effects of educational, financial and social resources of patients with different chronic health conditions on unplanned 30 day-readmission risks. The study made use of nationwide inpatient hospital data that was linked with Swiss census data. The sample included n = 62,109 patients aged 25 and older, hospitalized between 2012 and 2016 for one of 12 selected chronic conditions. Multivariate logistic regressions analysis was performed. Our results point to a significant association between social factors and readmission rates for patients with chronic conditions. Patients with upper secondary education (OR = 1.26, 95% CI: 1.11, 1.44) and compulsory education (OR = 1.51, 95% CI: 1.31, 1.74) had higher readmission rates than those with tertiary education when taking into account demographic, social and health status factors. Having private or semi-private hospital insurance was associated with a lower risk for 30-day readmission compared to patients with mandatory insurance (OR = 0.81, 95% CI: 0.73, 0.90). We did not find a general effect of social resources, measured by living with others in a household, on readmission rates. The risk of readmission for patients with chronic conditions was also strongly predicted by type of chronic condition and by factors related to health status, such as previous hospitalizations before the index hospitalization (+77%), number of comorbidities (+15% higher probability per additional comorbidity) as well as particularly long hospitalizations (+64%). Stratified analysis by type of chronic condition revealed differential effects of social factors on readmissions risks. Compulsory education was most strongly associated with higher odds for readmission among patients with lung cancer (+142%), congestive heart failure (+63%) and back problems (+53%). We assume that low socioeconomic status among patients with chronic conditions increases the risk of unplanned 30-day readmission after hospitalisation due to factors related to their social situation (e.g., low health literacy, material deprivation, high social burden), which may negatively affect cooperation with care providers and adherence to recommended therapies as well as hamper active participation in the medical process and the development of a shared understanding of the disease and its cure. Higher levels of comorbidity in socially disadvantaged patients can also make appropriate self-management and use of outpatient care more difficult. Our findings suggest a need for increased preventive measures for disadvantaged populations groups to promote early detection of diseases and to remove financial or knowledge-based barriers to medical care. Socially disadvantaged patients should also be strengthened more in their individual and social resources for coping with illness.

Social inequalities, length of hospital stay for chronic conditions and the mediating role of comorbidity and discharge destination: A multilevel analysis of hospital administrative data linked to the population census in Switzerland.

Social factors are recognized determinants of morbidity and mortality and also have an impact on use of medical services. The objective of this study was to assess the associations of educational attainment, social and financial resources, and migration factors with length of hospital stays for chronic conditions. In addition, the study investigated the role of comorbidity and discharge destination in mediating these associations. The study made use of nationwide inpatient data that was linked with Swiss census data. The study sample included n = 141,307 records of n = 92,623 inpatients aged 25 to 84 years, hospitalized between 2010 and 2016 for a chronic condition. Cross-classified multilevel models and mediation analysis were performed. Patients with upper secondary and compulsory education stayed longer in hospital compared to those with tertiary education (ß 0.24 days, 95% CI 0.14-0.33; ß 0.37, 95% CI 0.27-0.47, respectively) when taking into account demographic factors, main diagnosis and clustering on patient and hospital level. However, these effects were almost fully mediated by burden of comorbidity. The effect of living alone on length of stay (ß 0.60 days, 95% CI 0.50-0.70) was partially mediated by both burden of comorbidities (33%) and discharge destination (30.4%). (Semi-) private insurance was associated with prolonged stays, but an inverse effect was observed for colon and breast cancer. Allophone patients had also prolonged hospital stays (ß 0.34, 95% CI 0.13-0.55). Hospital stays could be a window of opportunity to discern patients who need additional time and support to better cope with everyday life after discharge, reducing the risks of future hospital stays. However, inpatient care in Switzerland seems to take into account rather obvious individual needs due to lack of immediate support at home, but not necessarily more hidden needs of patients with low health literacy and less resources to assert their interests within the health system.

Social and Regional Factors Predict the Likelihood of Admission to a Nursing Home After Acute Hospital Stay in Older People With Chronic Health Conditions: A Multilevel Analysis Using Routinely Collected Hospital and Census Data in Switzerland.

If hospitalization becomes inevitable in the course of a chronic disease, discharge from acute hospital care in older persons is often associated with temporary or persistent frailty, functional limitations and the need for help with daily activities. Thus, acute hospitalization represents a particularly vulnerable phase of transient dependency on social support and health care. This study examines how social and regional inequality affect the decision for an institutionalization after acute hospital discharge in Switzerland. The current analysis uses routinely collected inpatient data from all Swiss acute hospitals that was linked on the individual level with Swiss census data. The study sample included 60,209 patients 75 years old and older living still at a private home and being hospitalized due to a chronic health condition in 199 hospitals between 2010 and 2016. Random intercept multilevel logistic regression was used to assess the impact of social and regional factors on the odds of a nursing home admission after hospital discharge. Results show that 7.8% of all patients were admitted directly to a nursing home after hospital discharge. We found significant effects of education level (compulsory vs. tertiary education OR = 1.16 (95% CI: 1.03-1.30), insurance class (compulsory vs. private insurance OR = 1.24 (95% CI: 1.09-1.41), living alone vs. living with others (OR = 1.64; 95% CI: 1.53-1.76) and language regions (French vs. German speaking part: OR = 0.54; 95% CI: 0.37-0.80) on the odds of nursing home admission in a model adjusted for age, gender, nationality, health status, year of hospitalization and hospital-level variance. The language regions moderated the effect of education and insurance class but not of living alone. This study shows that acute hospital discharge in older age is a critical moment of transient dependency especially for socially disadvantaged patients. Social and health care should work coordinated together to avoid unnecessary institutionalizations.

Improvements in PM10 exposure and reduced rates of respiratory symptoms in a cohort of Swiss adults (SAPALDIA).

RATIONALE: Reductions in mortality following improvements in air quality were documented by several studies, and our group found, in an earlier analysis, that decreasing particulate levels attenuate lung function decline in adults. OBJECTIVES: We investigated whether decreases in particulates with an aerodynamic diameter of less than 10 microm (PM10) were associated with lower rates of reporting respiratory symptoms (i.e., decreased morbidity) on follow-up. METHODS: The present analysis includes 7,019 subjects who underwent detailed baseline examinations in 1991 and a follow-up interview in 2002. Each subject was assigned model-based estimates of average PM10 during the 12 months preceding each health assessment and the difference was used as the exposure variable of interest (DeltaPM10). Analyses were stratified by symptom status at baseline and associations between DeltaPM10 and change in symptom status during follow-up were adjusted for important baseline characteristics, smoking status at follow-up, and season. We then estimated adjusted odds ratios for symptoms at follow-up and numbers of symptomatic cases prevented due to the observed reductions in PM10. MEASUREMENTS AND MAIN RESULTS: Residential exposure to PM10 was lower in 2002 than in 1991 (mean decline 6.2 microg/m3; SD = 3.9 microg/m3). Estimated benefits (per 10,000 persons) attributable to the observed changes in PM10-levels were: 259 (95% confidence interval [CI]: 102-416) fewer subjects with regular cough, 179 (95% CI, 30-328) fewer subjects with chronic cough or phlegm and 137 (95% CI, 9-266) fewer subjects with wheezing and breathlessness. CONCLUSIONS: Reductions in particle levels in Switzerland over the 11-year follow-up period had a beneficial effect on respiratory symptoms among adults.

Reduced exposure to PM10 and attenuated age-related decline in lung function.

BACKGROUND: Air pollution has been associated with impaired health, including reduced lung function in adults. Moving to cleaner areas has been shown to attenuate adverse effects of air pollution on lung function in children but not in adults. METHODS: We conducted a prospective study of 9651 adults (18 to 60 years of age) randomly selected from population registries in 1990 and assessed in 1991, with 8047 participants reassessed in 2002. There was complete information on lung volumes and flows (e.g., forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], FEV1 as a percentage of FVC, and forced expiratory flow between 25 and 75% of the FVC [FEF25-75]), smoking habits, and spatially resolved concentrations of particulate matter that was less than 10 microm in aerodynamic diameter (PM10) from a validated dispersion model assigned to residential addresses for 4742 participants at both the 1991 and the 2002 assessments and in the intervening years. RESULTS: Overall exposure to individual home outdoor PM10 declined over the 11-year follow-up period (median, -5.3 mug per cubic meter; interquartile range, -7.5 to -4.2). In mixed-model regression analyses, with adjustment for confounders, PM10 concentrations at baseline, and clustering within areas, there were significant negative associations between the decrease in PM10 and the rate of decline in FEV1 (P=0.045), FEV1 as a percentage of FVC (P=0.02), and FEF25-75 (P=0.001). The net effect of a decline of 10 microg of PM10 per cubic meter over an 11-year period was to reduce the annual rate of decline in FEV1 by 9% and of FEF25-75 by 16%. Cumulative exposure in the interval between the two examinations showed similar associations. CONCLUSIONS: Decreasing exposure to airborne particulates appears to attenuate the decline in lung function related to exposure to PM10. The effects are greater in tests reflecting small-airway function.

Characterization of source-specific air pollution exposure for a large population-based Swiss cohort (SAPALDIA).

BACKGROUND: Although the dispersion model approach has been used in some epidemiologic studies to examine health effects of traffic-specific air pollution, no study has evaluated the model predictions vigorously. METHODS: We evaluated total and traffic-specific particulate matter < 10 and < 2.5 microm in aero-dynamic diameter (PM(10), PM(2.5)), nitrogren dioxide, and nitrogen oxide concentrations predicted by Gaussian dispersion models against fixed-site measurements at different locations, including traffic-impacted, urban-background, and alpine settings between and across cities. The model predictions were then used to estimate individual subjects' historical and cumulative exposures with a temporal trend model. RESULTS: Modeled PM(10) and NO(2) predicted at least 55% and 72% of the variability of the measured PM(10) and NO(2), respectively. Traffic-specific pollution estimates correlated with the NO(x) measurements (R(2) >or=0.77) for background sites but not for traffic sites. Regional background PM(10) accounted for most PM(10) mass in all cities. Whereas traffic PM(10) accounted for < 20% of the total PM(10), it varied significantly within cities. The modeling error for PM(10) was similar within and between cities. Traffic NO(x) accounted for the majority of NO(x) mass in urban areas, whereas background NO(x) accounted for the majority of NO(x) in rural areas. The within-city NO(2) modeling error was larger than that between cities. CONCLUSIONS: The dispersion model predicted well the total PM(10), NO(x), and NO(2) and traffic-specific pollution at background sites. However, the model underpredicted traffic NO(x) and NO(2) at traffic sites and needs refinement to reflect local conditions. The dispersion model predictions for PM(10) are suitable for examining individual exposures and health effects within and between cities.

Annoyance due to air pollution in Europe.

BACKGROUND: Annoyance due to air pollution is a subjective score of air quality, which has been incorporated into the National Environmental monitoring of some countries. The objectives of this study are to describe the variations in annoyance due to air pollution in Europe and its individual and environmental determinants. METHODS: This study took place in the context of the European Community Respiratory Health Survey II (ECRHS II) that was conducted during 1999-2001. It included 25 centres in 12 countries and 7867 randomly selected adults from the general population. Annoyance due to air pollution was self-reported on an 11-point scale. Annual mean mass concentration of fine particles (PM(2.5)) and its sulphur (S) content were measured in 21 centres as a surrogate of urban air pollution. RESULTS: Forty-three per cent of participants reported moderate annoyance (1-5 on the scale) and 14% high annoyance (> or =6) with large differences across centres (2-40% of high annoyance). Participants in the Northern European countries reported less annoyance. Female gender, nocturnal dyspnoea, phlegm and rhinitis, self-reported car and heavy vehicle traffic in front of the home, high education, non-smoking and exposure to environmental tobacco smoke were associated with higher annoyance levels. At the centre level, adjusted means of annoyance scores were moderately associated with sulphur urban levels (slope 1.43 microg m(-3), standard error 0.40, r = 0.61). CONCLUSIONS: Annoyance due to air pollution is frequent in Europe. Individuals' annoyance may be a useful measure of perceived ambient quality and could be considered a complementary tool for health surveillance.

Indoor time-microenvironment-activity patterns in seven regions of Europe.

Personal exposure to environmental substances is largely determined by time-microenvironment-activity patterns while moving across locations or microenvironments. Therefore, time-microenvironment-activity data are particularly useful in modeling exposure. We investigated determinants of workday time-microenvironment-activity patterns of the adult urban population in seven European cities. The EXPOLIS study assessed workday time-microenvironment-activity patterns among a total of 1427 subjects (age 19-60 years) in Helsinki (Finland), Athens (Greece), Basel (Switzerland), Grenoble (France), Milan (Italy), Prague (Czech Republic), and Oxford (UK). Subjects completed time-microenvironment-activity diaries during two working days. We present time spent indoors--at home, at work, and elsewhere, and time exposed to tobacco smoke indoors for all cities. The contribution of sociodemographic factors has been assessed using regression models. More than 90% of the variance in indoor time-microenvironment-activity patterns originated from differences between and within subjects rather than between cities. The most common factors that were associated with indoor time-microenvironment-activity patterns, with similar contributions in all cities, were the specific work status, employment status, whether the participants were living alone, and whether the participants had children at home. Gender and season were associated with indoor time-microenvironment-activity patterns as well but the effects were rather heterogeneous across the seven cities. Exposure to second-hand tobacco smoke differed substantially across these cities. The heterogeneity of these factors across cities may reflect city-specific characteristics but selection biases in the sampled local populations may also explain part of the findings. Determinants of time-microenvironment-activity patterns need to be taken into account in exposure assessment, epidemiological analyses, exposure simulations, as well as in the development of preventive strategies that focus on time-microenvironment-activity patterns that ultimately determine exposures.

Living near main streets and respiratory symptoms in adults: the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults.

The Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA), conducted in 1991 (SAPALDIA 1) in eight areas among 9,651 randomly selected adults aged 18-60 years, reported associations among the prevalence of respiratory symptoms, nitrogen dioxide, and particles with an aerodynamic diameter of less than 10 microg/m3. Later, 8,047 subjects reenrolled in 2002 (SAPALDIA 2). The effects of individually assigned traffic exposures on reported respiratory symptoms were estimated, while controlling for socioeconomic and exposure- and health-related factors. The risk of attacks of breathlessness increased for all subjects by 13% (95% confidence interval: 3, 24) per 500-m increment in the length of main street segments within 200 m of the home and decreased in never smokers by 12% (95% confidence interval: 0, 22) per 100-m increment in distance from home to a main street. Living within 20 m of a main street increased the risks of regular phlegm by 15% (95% confidence interval: 0, 31) and wheezing with breathing problems by 34% (95% confidence interval: 0, 79) in never smokers. In 2002, the effects related to road distance were different from those in 1991, which could be due to changes in the traffic pollution mixture. These findings among a general population provide strong confirmation that living near busy streets leads to adverse respiratory health effects.

Decline of ambient air pollution levels and improved respiratory health in Swiss children.

The causality of observed associations between air pollution and respiratory health in children is still subject to debate. If reduced air pollution exposure resulted in improved respiratory health of children, this would argue in favor of a causal relation. We investigated whether a rather moderate decline of air pollution levels in the 1990s in Switzerland was associated with a reduction in respiratory symptoms and diseases in school children. In nine Swiss communities, 9,591 children participated in cross-sectional health assessments between 1992 and 2001. Their parents completed identical questionnaires on health status and covariates. We assigned to each child an estimate of regional particles with an aerodynamic diameter < 10 microg/m3 (PM10) and determined change in PM10 since the first survey. Adjusted for socioeconomic, health-related, and indoor factors, declining PM10 was associated in logistic regression models with declining prevalence of chronic cough [odds ratio (OR) per 10-microg/m3 decline = 0.65, 95% confidence interval (CI), 0.54-0.79], bronchitis (OR = 0.66; 95% CI, 0.55-0.80), common cold (OR = 0.78; 95% CI, 0.68-0.89), nocturnal dry cough (OR = 0.70; 95% CI, 0.60-0.83), and conjunctivitis symptoms (OR = 0.81; 95% CI, 0.70-0.95). Changes in prevalence of sneezing during pollen season, asthma, and hay fever were not associated with the PM10 reduction. Our findings show that the reduction of air pollution exposures contributes to improved respiratory health in children. No threshold of adverse effects of PM10 was apparent because we observed the beneficial effects for relatively small changes of rather moderate air pollution levels. Current air pollution levels in Switzerland still exceed limit values of the Swiss Clean Air Act; thus, children's health can be improved further.

Follow-up of the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA 2) 1991-2003: methods and characterization of participants.

OBJECTIVES: The Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) was designed to investigate the health effects from long-term exposure to air pollution. METHODS: The health assessment at recruitment (1991) and at the first reassessment (2001-3) consisted of an interview about respiratory health, occupational and other exposures, spirometry, a methacholine bronchial challenge test, end-expiratory carbon monoxide (CO) measurement and measurement for atopy. A bio bank for DNA and blood markers was established. Heart rate variability was measured using a 24-hour ECG (Holter) in a random sample of participants aged 50 years and older. Concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3) and particulates in ambient air have been monitored in all study areas since 1991. Residential histories collected over the 11 year follow-up period coupled with GIS modelling will provide individual long-term air pollutant exposure estimates. RESULTS: Of 9651 participants examined in 1991, 8715 could be traced for the cohort study and 283 died. Basic information about health status was obtained for 8047 individuals (86% of alive persons), 6 528 individuals (70%) agreed to the health examination and 5 973 subjects (62%) completed the entire protocol. Non-participants in the reassessment were on average younger than participants and more likely to have been smokers and to have reported respiratory symptoms in the first assessment. Average weight had increased by 5.5 kg in 11 years and 28% of smokers in 1991 had quit by the time of the reassessment.