Analysis of the direct economic impact of smoking-related hospitalizations in Italy.

INTRODUCTION: Tobacco-related diseases have a substantial economic impact in terms of medical expenses, loss of productivity, and premature death. Tobacco use is estimated to be responsible for more than 90000 deaths each year in Italy. We aimed to evaluate the annual direct economic impact on the National Health System of hospitalizations attributable to tobacco smoking in Italy. METHODS: We analyzed data from all the hospitalizations of patients aged ≥30 years that occurred in Italy for 12 selected tobacco-related diseases, during 2018. These diseases included oropharyngeal cancer, esophageal cancer, gastric cancer, lung cancer, pancreatic cancer, bladder cancer, laryngeal cancer, ischemic heart disease, stroke, diseases of arteries, arterioles, and capillaries, pneumonia and influenza, and chronic obstructive pulmonary disease. We obtained information on 984322 hospital discharge records, including each hospitalization's direct costs. Using relative risk estimates from the scientific literature, we computed the population attributable fraction for various tobacco-related diseases to estimate the economic impact attributable to tobacco smoking. RESULTS: One-third of all hospitalizations occurred in 2018 in Italy among people aged ≥30 years for 12 tobacco-related diseases were found to be attributable to smoking, accounting for a total cost of €1.64 billion. Among the diseases considered, those with the highest expenditures attributable to tobacco smoking were ischemic heart disease, cerebrovascular disease, and lung cancer, accounting for €556 million, €290 million, and €229 million, respectively. CONCLUSIONS: Tobacco has a substantial economic impact in Italy, accounting for around 6% of the total cost of hospitalizations in 2018. This figure is expected to be largely underestimated due to several conservative assumptions adopted in the statistical analyses. It is imperative to prioritize comprehensive tobacco control measures to counteract the huge healthcare costs due to tobacco smoking.

Trends in Net Survival from Vulvar Squamous Cell Carcinoma in Italy (1990-2015).

(1) Objective: In many Western countries, survival from vulvar squamous cell carcinoma (VSCC) has been stagnating for decades or has increased insufficiently from a clinical perspective. In Italy, previous studies on cancer survival have not taken vulvar cancer into consideration or have pooled patients with vulvar and vaginal cancer. To bridge this knowledge gap, we report the trend in survival from vulvar cancer between 1990 and 2015. (2) Methods: Thirty-eight local cancer registries covering 49% of the national female population contributed the records of 6274 patients. Study endpoints included 1- and 2-year net survival (NS) calculated using the Pohar-Perme estimator and 5-year NS conditional on having survived two years (5|2-year CNS). The significance of survival trends was assessed with the Wald test on the coefficient of the period of diagnosis, entered as a continuous regressor in a Poisson regression model. (3) Results: The median patient age was stable at 76 years. One-year NS decreased from 83.9% in 1990-2001 to 81.9% in 2009-2015 and 2-year NS from 72.2% to 70.5%. Five|2-year CNS increased from 85.7% to 86.7%. These trends were not significant. In the age stratum 70-79 years, a weakly significant decrease in 2-year NS from 71.4% to 65.7% occurred. Multivariate analysis adjusting for age group at diagnosis and geographic area showed an excess risk of death at 5|2-years, of borderline significance, in 2003-2015 versus 1990-2002. (4) Conclusions: One- and 2-year NS and 5|2-year CNS showed no improvements. Current strategies for VSCC control need to be revised both in Italy and at the global level.

Immunogenicity and effectiveness of BNT162b2 COVID-19 vaccine in a cohort of healthcare workers in Milan (Lombardy Region, Northern Italy).

OBJECTIVES: to evaluate immunogenicity and effectiveness of BNT162b2 COVID-19 vaccine in a cohort of healthcare workers (HCWs). DESIGN: cohort study. SETTING AND PARTICIPANTS: in a hospital in Milan (Lombardy Region, Northern Italy) HCWs without ("negative cohort") and with ("positive cohort") history of SARS-CoV-2 infection or elevated serum antibody before the vaccination campaign (27.12.2020) were included. Data collection and follow-up covered the period 27.12.2020-13.05.2022. MAIN OUTCOMES MEASURES: 1. serum anti-spike-1 (anti-S1) antibody levels after vaccination; 2. vaccine effectiveness (VE) against SARS-CoV-2 infections (either symptomatic or not) in the negative cohort. Data on infections were extracted from multiple sources (laboratory, accident reports, questionnaires). Vaccination was treated as a time-dependent variable. Using unvaccinated person-time as reference, hazard ratios (HR) of infections and 95% confidence intervals (95%CI) were calculated with a Cox regression model adjusted for gender, age, and occupation. VE was calculated as (1 - HR)×100. RESULTS: 5,596 HCWs were included, 4,771 in the negative and 825 in the positive cohort. In both cohorts, serum anti-S1 antibodies were high one months after the second dose, halved after six months, and returned to high levels after the third dose. In the negative cohort, 1,401 SARS-CoV-2 infections were identified. VE was 70% (95%CI 54-80; 46 infected) in the first four months after the second dose and later declined to 16% (95%CI 0-43; 97 infected). After the third dose, VE increased to 57% (95%CI 35-71; 61 infected) in the first month but rapidly declined over time, particularly after three months (24% in the fourth month and 1% afterwards). The number of infections avoided by vaccination was estimated to be 643 (95%CI 236-1,237). CONCLUSIONS: in spite of rapidly declining effectiveness, vaccination helped to avoid several hundred infections in the considered hospital.

A real world analysis of COVID-19 impact on hospitalizations in older adults with chronic conditions from an Italian region.

Healthcare delivery reorganization during the COVID-19 emergency may have had a significant impact on access to care for older adults with chronic conditions. We investigated such impact among all adults with chronic conditions aged ≥ 65 years, identified through the electronic health databases of two local health agencies-ATS Brianza and ATS Bergamo-from the Lombardy region, Italy. We considered hospitalizations for 2020 compared to the average 2017-2019 and quantified differences using rate ratios (RRs). Overall, in 2017-2019 there were a mean of 374,855 older adults with  ≥ 1 chronic condition per year in the two ATS and 405,371 in 2020. Hospitalizations significantly decreased from 84,624 (225.8/1000) in 2017-2019 to 78,345 (193.3/1000) in 2020 (RR 0.86). Declines were reported in individuals with many chronic conditions and for most Major Diagnostic Categories, except for diseases of the respiratory system. The strongest reductions were observed in hospitalizations for individuals with active tumours, particularly for surgical ones. Hospitalization rates increased in individuals with diabetes, likely due to COVID-19-related diseases. Although determinants of the decrease in demand and supply for care among chronic older adults are to be further explored, this raises awareness on their impacts on chronic patients' health in the medium and long run.

[Effects on mortality and morbidity among the population living close to the Valmadrera (Lombardy Region, Northern Italy) incinerator]. / Effetti sulla mortalità e morbilità nella popolazione residente nei pressi dell'inceneritore di Valmadrera (LC).

OBJECTIVES: assessment of the health effects on the resident population around the incinerator for municipal solid waste in Valmadrera (Lombardy Region, Northern Italy) in relation to the exposure level to the pollutants produced by the plant. DESIGN: historical cohort study, based on the resident population from 2003 to 2016 in the study area. With a dispersion model, based on PM10 emitted by the plant, three areas of exposure (high, medium, low) were defined and, on the basis of the residence of the cohort, different exposure levels were attributed to the subjects. The association between level of exposure and health effects were estimated by comparing the high and medium exposure levels with the low exposure level, using a Cox model, adjusted for age and socioeconomic deprivation index. MAIN OUTCOME MEASURES: mortality rates, hospitalization rates, cancer incidence rates, and perinatal outcomes were analysed for the main causes potentially associated with exposure to incineration plants. RESULTS: the subjects enrolled in the cohort were 106,056 (1,000,242 person-years). There were no statistically significant excesses of risk for almost all the outcomes investigated. Excessive mortality and hospitalization were found for liver/biliary cancers (HR women: 2.57; 95%CI 1.15-2.79; HR men: 2.22; 95%CI 1.10-4, 84). In the municipality where the plant is located, an excess prevalence (OR 1.78; 95%CI 1.43-2.21) of hepatitis C was found. CONCLUSIONS: the results suggest the absence of a relationship between residence in areas with different levels of pollutants emitted by the plant and the onset of almost all diseases. The associated causes do not have aetiological plausibility with exposure to pollutants from waste incineration. In particular, for liver/liver and biliary cancer, the association with infectious causes rather than exposure to environmental pollutants is more plausible.

Side effects among healthcare workers from a large Milan university hospital after second dose of BNT162b2 mRNA COVID-19 vaccine.

BACKGROUND: In Italy, healthcare workers (HCWs) were among the first to receive COVID-19 vaccination. Aim of the present study is to evaluate frequency and severity of adverse events (AEs) following the second dose of BNT162b2 vaccine among HCWs of a large university hospital in Milan, Italy. METHODS: One month after having received the second dose of vaccine, HCWs filled-in a form about type, severity, and duration of post-vaccination local and systemic symptoms. We calculated the overall frequency of AEs and used multivariable Poisson regression models (adjusted for sex, age, BMI, smoking, allergy history, previous SARS-CoV-2 infection, anti-hypertensive therapy, and occupation) to calculate risk ratios (RR) and 95% confidence intervals (CI) of AEs according to selected variables. RESULTS: We included 3659 HCWs. Overall, 2801 (76.6%) experienced at least one local event, with pain at injection site being the most frequent (2788, 76.2%). Systemic events were reported by 2080 (56.8%) HCWs, with fatigue (52.3%), muscle pain (42.2%), headache (37.7%), joint pain (31.9%), and fever (26.2%) being the most frequent. Risks of systemic events were associated with female gender (RR=1.14, CI: 1.06-1.23), age (strong decrease with increasing age, p-trend<0.001), allergy history (RR=1.13, CI: 1.05-1.20), and current smoking (RR=0.90, CI: 0.84-0.97). HCWs with previous SARS-CoV-2 infection (even if symptomatic) were not at increased risk. CONCLUSIONS: Both local and systemic acute effects after second dose of BNT162b2 vaccine were frequently reported. However, symptoms were mostly light/mild and of short duration. Thus, our findings support the safety of COVID-19 vaccination in adults in relatively good health.

Incidence trends of vulvar squamous cell carcinoma in Italy from 1990 to 2015.

OBJECTIVE: The incidence of vulvar squamous cell carcinoma has increased for decades in most Western countries - a trend virtually restricted to women aged <50 or 60 years. In southern Europe, conversely, the trends have been insufficiently studied. This article reports a study from Italy. METHOD: Thirty-eight local cancer registries, currently covering 15,274,070 women, equivalent to 49.2% of the Italian national female population, participated. Invasive cancers registered between 1990 and 2015 with an International Classification of Diseases for Oncology, 3rd revision, topography code C51 and morphology codes compatible with vulvar squamous cell carcinoma (n = 6294) were eligible. Incidence trends were analysed using joinpoint regression models, with calculation of the estimated annual percent change (EAPC), and age-period-cohort models. RESULTS: Total incidence showed a regular and significant decreasing trend (EAPC, -0.96; 95% confidence interval (CI), -1.43 to -0.48). This was entirely accounted for by women aged ≥60 years (EAPC, -1.34; 95% CI, -1.86 to -0.81). For younger women, the EAPC between 1990 and 2012 was 1.20 (95% CI, 0.34 to 2.06) with a non-significant acceleration thereafter. This pattern did not vary substantially in a sensitivity analysis for the effect of geographic area and duration of the registry. The age-period-cohort analysis revealed a risk decrease in cohorts born between 1905 and 1940 and a new increase in cohorts born since 1945. CONCLUSIONS: The decreasing trend observed among older women and the resulting decrease in total rate are at variance with reports from most Western countries. Age-period-cohort analysis confirmed a decreasing trend for earliest birth cohorts and an opposite one for recent ones.

Indicators based on registers and administrative data for breast cancer: routine evaluation of oncologic care pathway can be implemented.

RATIONALE, AIMS AND OBJECTIVES: Assuring the best standards of care - in a sustainable way - in chronic diseases as breast cancer is nowadays an important challenge for any health system. The aim of this study was to present the methodology used to define a set of quality indicators, computable from administrative data for the pathway of care of breast cancer, and its application at a population level. METHOD: The cohort of 2007-2009 incident cases of breast cancer was identified through a network of six cancer registers in Northern Italy. Cases of sarcoma and lymphoma, patients with multiple primary cancers and those metastatic at diagnosis were excluded; 9614 women were retained for the analysis. For each indicator, the sub-cohort of women eligible for the diagnostic/therapeutic procedures was identified and calculations were performed through record linkage between the cohort and sources of health information. Data on potential available confounders or prognostic factors were also collected. RESULTS: For a few indicators, such as cyto-histological assessment before surgery (62%) and intensive follow-up (79%), deviation from recommendations was evident. Younger patients (≤50 years) more frequently needed a short term re-intervention, while older patients less frequently underwent reconstructive surgery and received palliative care. Several indicators had a great variability across hospitals. In some cases, this heterogeneity appeared to be related to the hospital size, with high-volume hospitals being more compliant to guidelines. CONCLUSION: It is possible to evaluate the quality of cancer care delivered in clinical practice in recent years, in order to implement interventions aimed to improve adherence to international standards of care.

Mortality at 30 and 90 days in elderly patients with pulmonary embolism: a retrospective cohort study.

Pulmonary Embolism (PE) incidence increases with age. Data on mortality and prognosis in elderly patients with suspected PE are lacking. (1) To assess 30- and 90-day mortality in subjects with PE from an elderly population seen in the emergency department (ED); (2) to test the prognostic accuracy of a simplified Pulmonary Embolism Severity Index (sPESI) coupled to a highly sensitive cardiac Troponin T (hs-cTnT) level. A retrospective cohort study was performed, including patients evaluated in the ED of Vimercate Hospital for clinically suspected PE from 2010 to 2012. Study population: n = 470, 63.4% women, mean age ± SD 73.06 ± 16.0 years, 40% aged ≥80 and 77.7% ≥65 years old, confirmed PE: 22.6% (106 cases). Within 30 and 90 days, mortality among patients with confirmed PE was 14.2% (8.8-22.0) and 20.8% (16.5-41.7). In subjects aged ≥80 years, 30-day mortality was 18.9% among patients with confirmed PE, and 12.6% among those with PE excluded (p = 0.317). Ninety-day mortality rates were 29.7 and 19.9%, respectively (p = 0.193). In patients with confirmed PE, Negative Predictive Value of sPESI was 94.1% (80.3-99.3) for 30 days and 88.2% (72.3-96.7) for 90-day mortality. Adding the hs-cTnT level to sPESI did not improve its performance. (1) In an elderly population referring to the ED with clinically suspected PE, mortality was high both in subjects with and without confirmed PE; (2) the ability of sPESI and hs-cTnT to predict PE mortality seems to be lower than reported in studies based on data from younger populations. Better risk stratification tools will be necessary to improve clinical management in this setting.

[A set of indicators to monitor the adherence to the guidelines for the diagnosis and treatment of breast cancer]. / Indicatori per il monitoraggio dei percorsi diagnostico-terapeutici del tumore della mammella.

OBJECTIVES: to present a set of indicators developed from six Local Health Authorities of the Lombardy Region to monitor the diagnostic and therapeutic pathway of breast cancer patients, applied to 2007-2009 incident cases. DESIGN: retrospective cohort study. SETTING AND PARTICIPANTS: all subjects with primary breast cancer, incident in the period 2007-2009, and collected by cancer registries of Milano 1, Bergamo, Cremona, Milano, Milano 2 and Monza-Brianza (5,320,272 inhabitants) were included. MAIN OUTCOME MEASURES: through the use of combined current health databases (health registry, hospitalizations, outpatient, pharmaceutical prescription and specific database for anticancer drugs), for each incident case 34 different indicators have been developed to measure the appropriateness of the procedures provided for diagnosis, treatment (surgical and medical) and follow-up. For each indicator, we analyzed the relationship with age, stage, deprivation index, type of treatment, volume of the specific procedure of the hospital where primary surgery was performed. Estimates were adjusted using multilevel regression models. RESULTS: 12,988 incident cases, without metastatic diseases and other cancers, were included in the cohort: 62% were localized to the breast, 33% to the axillary lymph-nodes, 3% metastatic ab initio, and 2% with unknown stage. Deviations from the expected value of different magnitude depending on the type of indicator were observed: the most important differences were detected for the follow-up indicators. There was, in fact, an excess of several procedures in the first year of follow-up: 75% of the cases performed a dosage of a tumor marker, 67% an ecography or a CT scan or an MR, and 37% a bone scan. On the other hand, the access to neoadjuvant and adjuvant treatments in older women was far below the expected values. CONCLUSIONS: the study presents data derived from a large cohort of population cases; the set of indicators was validated by a board of oncologists. The use of indicators calculated by linking the cancer registries (that provide staging) and administrative databases allows the assessment of compliance to the guidelines for diagnosis and treatment of tumours. This experience shows that it is possible to develop a methodology, shared with clinicians, to define indicators that measure the distance between guidelines and current clinical practice in order to decrease variability, to limit inappropriateness, and to reduce unnecessary diagnostic tests for patients (and, consequently, hospitals organizational overload). In order to be sustainable and equitable, a health care system must be able to ensure implementation of protocols/procedures based exclusively on the best available scientific evidences.

[Environmental indicators in ten Italian cities (2001-2005): the air quality data for epidemiological surveillance]. / Indicatori ambientali in dieci città italiane (2001-2005): i dati di qualità dell'aria per la sorveglianza epidemiologica.

OBJECTIVE: to produce environmental indicators suitable for an epidemiological surveillance in 10 Italian cities part of the EpiAir Project (2001-2005). METHODS: the environmental parameters that correlate to relevant health effects are the particles with diameters less than or equal to 10 micrometers (PM10), the nitrogen dioxide (NO2) and the ozone (O3). The necessary meteorological data are: temperature, relative humidity, barometric pressure and apparent temperature.We have identified some criteria to select monitoring stations and have taken standard methods of calculation to produce environmental indicators starting from the daily data available after closely evaluating the completeness of the existing data. Furthermore, we have checked the homogeneity of the selected data to ensure that it represents the population's exposure. RESULTS: close examination of descriptive statistics shows a critical situation of the considered pollutants. The analysis of the yearly state underlines for PM10 values higher than 40 microg/m3 in the area of Mestre-Venice and in Milan, Turin, Bologna e Taranto. For NO2, values are consistently above 40 microg/m3 in Milan, Turin, Bologna, Florence, Rome and Palermo. For ozone, the concentrations were stable, with the exception of Summer 2003 when we recorded, on average, an increase of 13% compared to the mean value estimated for the ten cities during the study period, especially in Mestre-Venice, Turin and Palermo. CONCLUSIONS: it is important to ensure the consistency of the methods and instruments in environmental monitoring. To evaluate health effects and perform interventions over the longterm, it is therefore fundamental that the data be homogenous, especially during the periodic reorganizations and rationalizations of air quality management. It is also necessary to include daily meteorological data that influence pollutant dispersion and population health status.

[Air pollution and mortality in ten Italian cities. Results of the EpiAir Project]. / Inquinamento atmosferico e mortalità in dieci città italiane. Risultati del Progetto EpiAir.

OBJECTIVE: the relationship between air pollution and mortality has been well established in national and international scientific literature. This study reports the results of the EpiAir Project relative to the effect of air pollution on mortality in 10 Italian cities during 2001-2005. The association between particulate matter (PM10) and gases (nitrogen dioxide, NO2, and ozone, O3), and all natural mortality, as well as cardiac, cerebrovascular and respiratory mortality, is presented. Specific issues have been investigated, such as the latency of the air pollution-mortality effects and the identification of individual demographic characteristics and clinical conditions that result in greater susceptibility to the effects of particulate matter. METHODS: the study population consisted of 276,205 subjects aged 35+ years old, resident in one of the 10 Italian cities studied, which died in the city between 2001-2005. For each subject, information was collected on cause of death, location of death, demographical variables and hospital discharge diagnoses in the previous 2-year period. The statistical analysis was adjusted for the relevant temporal and meteorological factors using the case-crossover approach. The results for ozone are limited to the warm semester (April through September). An analysis of the association between air pollution and mortality was conducted for each city, and the city-specific estimates were meta-analyzed on a second level to obtain a pooled result, and reported inter-city heterogeneity. RESULTS: a short-term effect of PM10 on mortality has been detected for all the groups of causes considered, with latencies ranging from lag 0 for cerebrovascular mortality to lag 0-3 for respiratory mortality. The association between NO2 and mortality displays strong and similar effects for all death causes, with prolonged effects (lag 0-5) for all groups of causes. The results for O3 are similar to those found for NO2, with prolonged latency (lag 0-5) for all causes of death with the exception of cerebrovascular mortality, for which a delayed effect (lag 3-5) was identified. Individual susceptibility factors of the PM10-natural mortality association include age, as elderly subjects are especially vulnerable to the effects of particles. CONCLUSIONS: the main results of the study suggest that the air pollution originated by vehicular traffic is the most relevant environmental problem in Italian cities from a public health viewpoint.

Particulate matter and daily mortality: a case-crossover analysis of individual effect modifiers.

BACKGROUND: Several time-series studies have established the relationship between particulate matter (PM10) and mortality. We adopted a case-crossover design to evaluate whether individual socio-demographic characteristics and chronic or acute medical conditions modify the PM10-mortality association. METHODS: We selected all natural deaths (321,024 subjects) occurring among adult (aged 35+ years) residents of 9 Italian cities between 1997 and 2004. We had access to individual information on socio-demographic variables, location of death, and chronic conditions (hospital admissions in the preceding 2-year period). For in-hospital deaths, we collected information on treatment wards at time of death and acute medical conditions. In a case-crossover analysis we adjusted for time, population changes, and meteorological conditions. RESULTS: PM10 was associated with mortality among subjects age 65 years and older (0.75% increase per 10 microg/m3 [95% confidence interval = 0.42% to 1.09%]), with a more pronounced effect among people age 85 and older. A weaker effect was found among the most affluent people. The effect was present for both out-of-hospital and in-hospital deaths, especially among those treated in general medicine and other less specialized wards. PM10 effects were stronger among people with diabetes (1.03% [0.28% to 1.79%]) and chronic obstructive pulmonary disease (0.84% [0.17% to 1.52%]). The acute conditions with the largest effect estimates were acute impairment of pulmonary circulation (4.56% [0.75% to 8.51%]) and heart failure (1.67% [0.30% to 3.04%]). CONCLUSIONS: Several factors, including advanced age, type of hospital ward, and chronic and acute health conditions, modify the PM10-related risk of death. Altered pulmonary circulation and heart failure are important effect modifiers, suggesting that cardiac decompensation is a possible mechanism of the fatal PM10 effect.

An ecological time-series study of heat-related mortality in three European cities.

BACKGROUND: Europe has experienced warmer summers in the past two decades and there is a need to describe the determinants of heat-related mortality to better inform public health activities during hot weather. We investigated the effect of high temperatures on daily mortality in three cities in Europe (Budapest, London, and Milan), using a standard approach. METHODS: An ecological time-series study of daily mortality was conducted in three cities using Poisson generalized linear models allowing for over-dispersion. Secular trends in mortality and seasonal confounding factors were controlled for using cubic smoothing splines of time. Heat exposure was modelled using average values of the temperature measure on the same day as death (lag 0) and the day before (lag 1). The heat effect was quantified assuming a linear increase in risk above a cut-point for each city. Socio-economic status indicators and census data were linked with mortality data for stratified analyses. RESULTS: The risk of heat-related death increased with age, and females had a greater risk than males in age groups > or =65 years in London and Milan. The relative risks of mortality (per degrees C) above the heat cut-point by gender and age were: (i) Male 1.10 (95%CI: 1.07-1.12) and Female 1.07 (1.05-1.10) for 75-84 years, (ii) M 1.10 (1.06-1.14) and F 1.08 (1.06-1.11) for > or = or =85 years in Budapest (> or =24 degrees C); (i) M 1.03 (1.01-1.04) and F 1.07 (1.05-1.09), (ii) M 1.05 (1.03-1.07) and F 1.08 (1.07-1.10) in London (> or =20 degrees C); and (i) M 1.08 (1.03-1.14) and F 1.20 (1.15-1.26), (ii) M 1.18 (1.11-1.26) and F 1.19 (1.15-1.24) in Milan (> or =26 degrees C). Mortality from external causes increases at higher temperatures as well as that from respiratory and cardiovascular disease. There was no clear evidence of effect modification by socio-economic status in either Budapest or London, but there was a seemingly higher risk for affluent non-elderly adults in Milan. CONCLUSION: We found broadly consistent determinants (age, gender, and cause of death) of heat related mortality in three European cities using a standard approach. Our results are consistent with previous evidence for individual determinants, and also confirm the lack of a strong socio-economic gradient in heat health effects currently in Europe.

Vulnerability to heat-related mortality: a multicity, population-based, case-crossover analysis.

BACKGROUND: Although studies have documented increased mortality during heat waves, little information is available on the subgroups most susceptible to these effects. We evaluated the effects of summertime high temperature on daily mortality among population subgroups defined by demographic characteristics, socioeconomic status, and episodes of hospitalization for various conditions during the preceding 2 years. METHODS: We studied a total of 205,019 residents of 4 Italian cities (Bologna, Milan, Rome, and Turin) age 35 or older who died during 1997-2003. The case-crossover design was applied to evaluate the association between mean apparent temperature (same and previous day) and all-cause mortality. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) of dying at 30 degrees C (apparent temperature) relative to 20 degrees C were estimated accounting for time, population changes, and air pollution. RESULTS: We found an overall OR of 1.34 (CI = 1.27-1.42) at 30 degrees C relative to 20 degrees C. The odds ratio increased with age and was higher among women (OR = 1.45; 1.37-1.52) and among widows and widowers (1.50; 1.33-1.69). Low area-based income modestly increased the effect. Among the preexisting medical conditions investigated, effect modification was detected for previous psychiatric disorders (1.69; 1.39-2.07), depression (1.72; 1.24-2.39), heart conduction disorders (1.77; 1.38-2.27), and circulatory disorders of the brain (1.47; 1.34-1.62). Temperature-related mortality was higher among people residing in nursing homes, and a large effect was also detected for hospitalized subjects. CONCLUSIONS: Subsets of the population that are particularly vulnerable to high summer temperatures include the elderly, women, widows and widowers, those with selected medical conditions, and those staying in nursing homes and healthcare facilities.