Development and validation of an electronic database-based frailty index to predict mortality and hospitalization in a population-based study of adults with SARS-CoV-2.

Background: Electronic health databases are used to identify people at risk of poor outcomes. Using electronic regional health databases (e-RHD), we aimed to develop and validate a frailty index (FI), compare it with a clinically based FI, and assess its association with health outcomes in community-dwellers with SARS-CoV-2. Methods: Data retrieved from the Lombardy e-RHD were used to develop a 40-item FI (e-RHD-FI) in adults (i.e., aged ≥18 years) with a positive nasopharyngeal swab polymerase chain reaction test for SARS-CoV-2 by May 20, 2021. The considered deficits referred to the health status before SARS-CoV-2. The e-RHD-FI was validated against a clinically based FI (c-FI) obtained from a cohort of people hospitalized with COVID-19 and in-hospital mortality was evaluated. e-RHD-FI performance was evaluated to predict 30-day mortality, hospitalization, and 60-day COVID-19 WHO clinical progression scale, in Regional Health System beneficiaries with SARS-CoV-2. Results: We calculated the e-RHD-FI in 689,197 adults (51.9% females, median age 52 years). On the clinical cohort, e-RHD-FI correlated with c-FI and was significantly associated with in-hospital mortality. In a multivariable Cox model, adjusted for confounders, each 0.1-point increment of e-RHD-FI was associated with increased 30-day mortality (Hazard Ratio, HR 1.45, 99% Confidence Intervals, CI: 1.42-1.47), 30-day hospitalization (HR per 0.1-point increment = 1.47, 99%CI: 1.46-1.49), and WHO clinical progression scale (Odds Ratio = 1.84 of deteriorating by one category, 99%CI 1.80-1.87). Conclusion: The e-RHD-FI can predict 30-day mortality, 30-day hospitalization, and WHO clinical progression scale in a large population of community-dwellers with SARS-CoV-2 test positivity. Our findings support the need to assess frailty with e-RHD.

Web-based surveillance of respiratory infection outbreaks: retrospective analysis of Italian COVID-19 epidemic waves using Google Trends.

Introduction: Large-scale diagnostic testing has been proven insufficient to promptly monitor the spread of the Coronavirus disease 2019. Electronic resources may provide better insight into the early detection of epidemics. We aimed to retrospectively explore whether the Google search volume has been useful in detecting Severe Acute Respiratory Syndrome Coronavirus outbreaks early compared to the swab-based surveillance system. Methods: The Google Trends website was used by applying the research to three Italian regions (Lombardy, Marche, and Sicily), covering 16 million Italian citizens. An autoregressive-moving-average model was fitted, and residual charts were plotted to detect outliers in weekly searches of five keywords. Signals that occurred during periods labelled as free from epidemics were used to measure Positive Predictive Values and False Negative Rates in anticipating the epidemic wave occurrence. Results: Signals from "fever," "cough," and "sore throat" showed better performance than those from "loss of smell" and "loss of taste." More than 80% of true epidemic waves were detected early by the occurrence of at least an outlier signal in Lombardy, although this implies a 20% false alarm signals. Performance was poorer for Sicily and Marche. Conclusion: Monitoring the volume of Google searches can be a valuable tool for early detection of respiratory infectious disease outbreaks, particularly in areas with high access to home internet. The inclusion of web-based syndromic keywords is promising as it could facilitate the containment of COVID-19 and perhaps other unknown infectious diseases in the future.

Two years of SARS-CoV-2 pandemic and COVID-19 in Lombardy, Italy.

Lombardy, the largest and most densely populated Italian region, was severely hit in February 2020 by the first pandemic wave of SARS-CoV-2 and associated COVID-19. Since then, additional infection waves spread in the region. The aim of this study was to compare the first with the subsequent waves using the administrative database of the Lombardy Welfare directorate. In the time frames of the four 2020-2022 waves, the absolute number of infected cases, sites of management and crude mortality rate associated with SARS-CoV-2 positivity were extracted from the database. Infected cases progressively increased in the region by approximately 5-fold in the second versus the first wave, 4-fold in the third and 20-fold during the most recent wave mainly associated with the omicron variant. The crude death decreased from 18.7% in the first to 2% in the second and third wave to reach a 0.3% nadir at the time of the fourth wave. This study confirms that in Lombardy outcomes of public health and health-care relevance such as deaths and number of hospitalizations declined dramatically across the four virus waves and reached very low values in 2022 when, at variance with the first three SARS-CoV-2 waves, the majority of infected cases had been previously vaccinated.

Natural and vaccine-induced immunity are equivalent for the protection against SARS-CoV-2 infection.

OBJECTIVES: To compare the long-term cumulative risk of SARS-CoV-2 infection associated with natural and vaccine-induced immunity. METHODS: Retrospective population-based cohort study based on registry of COVID-19 vaccinations and SARS-CoV-2 infections among 9.1 million citizens of Lombardy, Italy, eligible for vaccination on 27th December 2020. Those who developed SARS-CoV-2 infection from 24th May to 14th September 2021, provided they did not yet receive the COVID-19 vaccine when infection was confirmed, and those who received the second mRNA vaccine dose, provided they had not yet developed the infection, were selected to be 1:1 matched for sex, age and index date. The latter corresponded to 90 days after confirmed infection or 14 days after vaccine administration. A control cohort including citizens who, on the index date, had neither developed infection nor received vaccination was also selected. Kaplan-Meier curves were used for comparing the cumulative incidence of new SARS-CoV-2 infection from the index date until 22nd June 2022. RESULTS: Overall, 19,418 1:1:1 risk-sets were included. After 9 months of follow-up, the cumulative risk of new SARS-CoV-2 infection was 21.8%, 22.0%, and 25.9%, respectively, among exposed to natural immunity, vaccine-induced immunity and unexposed. CONCLUSIONS: Equivalent potential for protecting against new SARS-CoV-2 infection was observed.

Dipeptidyl Peptidase-4 Inhibitors, Glucagon-like Peptide-1 Receptor Agonists, and Sodium-Glucose Cotransporter-2 Inhibitors and COVID-19 Outcomes.

PURPOSE: It has been reported that dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and sodium-glucose cotransporter-2 inhibitors (SGLT-2i) have a role in modulation of inflammation associated with coronavirus disease 2019 (COVID-19). This study assessed the effect of these drug classes on COVID-19-related outcomes. METHODS: Using a COVID-19 linkable administrative database, we selected patients aged ≥40 years with at least 2 prescriptions of DPP-4i, GLP-1 RA, or SGLT-2i or any other antihyperglycemic drug and a diagnosis of COVID-19 from February 15, 2020, to March 15, 2021. Adjusted odds ratios (ORs) with 95% CIs were used to calculate the association between treatments and all-cause and in-hospital mortality and COVID-19-related hospitalization. A sensitivity analysis was performed by using inverse probability treatment weighting. FINDINGS: Overall, 32,853 subjects were included in the analysis. Multivariable models showed a reduction of the risk for COVID-19 outcomes for users of DPP-4i, GLP-1 RA, and SGLT-2i compared with nonusers, although statistical significance was reached only in DPP-4i users for total mortality (OR, 0.89; 95% CI, 0.82-0.97). The sensitivity analysis confirmed the main results reaching a significant reduction for hospital admission in GLP-1 RA users and in-hospital mortality in SGLT-2i users compared with nonusers. IMPLICATIONS: This study found a beneficial effect in the risk reduction of COVID-19 total mortality in DPP-4i users compared with nonusers. A positive trend was also observed in users of GLP-1 RA and SGLT-2i compared with nonusers. Randomized clinical trials are needed to confirm the effect of these drug classes as potential therapy for the treatment of COVID-19.

Post-COVID condition: dispensation of drugs and diagnostic tests as proxies of healthcare impact.

With the goal to increase knowledge on the healthcare impact of the post-COVID-19 condition we exploited the administrative claims database of Lombardy, the largest Italian region and the first after China to be heavily hit by the SARS-CoV-2 pandemic in February-May 2020. We chose to employ the dispensation of drugs and diagnostic tests as proxies of the impact of the post-COVID condition in 46,574 cases who recovered from COVID-19 and were negative at PCR testing within June 20, 2020. Data were obtained throughout the 18-month post-negativization period until December 2021 and results on the use of drugs and diagnostic tests were compared with those accrued in the same cases during the pre-COVID period in July-December 2019. After an increase in the first semester after SARS-CoV-2 negativization (July-December 2020), trends in the dispensation of drugs according to the broad ATC classes and of diagnostic tests decreased or remained substantially stable. However, dispensation of drugs for acid related disorders (A02), diabetes (A10), heparins (B01AB), direct oral anticoagulants (B01AP), antipsychotics (N05A), antidepressants (N06A) and for obstructive airways diseases (R03) was still higher than in the pre-COVID period. These findings, based upon drug and diagnostic test dispensation as proxies of the healthcare impact of the post-COVID condition, show that in a substantial proportion of recovered cases the post-COVID condition is active and clinically relevant 18 months after the acute disease. The findings also provide indirect evidence of the body organs and systems more compromised in the post-COVID period.

COVID-19-associated Guillain-Barré syndrome in the early pandemic experience in Lombardia (Italy).

OBJECTIVE: To estimate the incidence and describe clinical characteristics and outcome of GBS in COVID-19 patients (COVID19-GBS) in one of the most hit regions during the first pandemic wave, Lombardia. METHODS: Adult patients admitted to 20 Neurological Units between 1/3-30/4/2020 with COVID19-GBS were included as part of a multi-center study organized by the Italian society of Hospital Neuroscience (SNO). RESULTS: Thirty-eight COVID19-GBS patients had a mean age of 60.7 years and male frequency of 86.8%. CSF albuminocytological dissociation was detected in 71.4%, and PCR for SARS-CoV-2 was negative in 19 tested patients. Based on neurophysiology, 81.8% of patients had a diagnosis of AIDP, 12.1% of AMSAN, and 6.1% of AMAN. The course was favorable in 76.3% of patients, stable in 10.5%, while 13.2% worsened, of which 3 died. The estimated occurrence rate in Lombardia ranges from 0.5 to 0.05 GBS cases per 1000 COVID-19 infections depending on whether you consider positive cases or estimated seropositive cases. When we compared GBS cases with the pre-pandemic period, we found a reduction of cases from 165 to 135 cases in the 2-month study period in Lombardia. CONCLUSIONS: We detected an increased incidence of GBS in COVID-19 patients which can reflect a higher risk of GBS in COVID-19 patients and a reduction of GBS events during the pandemic period possibly due to a lower spread of more common respiratory infectious diseases determined by an increased use of preventive measures.

Detecting early signals of COVID-19 outbreaks in 2020 in small areas by monitoring healthcare utilisation databases: first lessons learned from the Italian Alert_CoV project.

BackgroundDuring the COVID-19 pandemic, large-scale diagnostic testing and contact tracing have proven insufficient to promptly monitor the spread of infections.AimTo develop and retrospectively evaluate a system identifying aberrations in the use of selected healthcare services to timely detect COVID-19 outbreaks in small areas.MethodsData were retrieved from the healthcare utilisation (HCU) databases of the Lombardy Region, Italy. We identified eight services suggesting a respiratory infection (syndromic proxies). Count time series reporting the weekly occurrence of each proxy from 2015 to 2020 were generated considering small administrative areas (i.e. census units of Cremona and Mantua provinces). The ability to uncover aberrations during 2020 was tested for two algorithms: the improved Farrington algorithm and the generalised likelihood ratio-based procedure for negative binomial counts. To evaluate these algorithms' performance in detecting outbreaks earlier than the standard surveillance, confirmed outbreaks, defined according to the weekly number of confirmed COVID-19 cases, were used as reference. Performances were assessed separately for the first and second semester of the year. Proxies positively impacting performance were identified.ResultsWe estimated that 70% of outbreaks could be detected early using the proposed approach, with a corresponding false positive rate of ca 20%. Performance did not substantially differ either between algorithms or semesters. The best proxies included emergency calls for respiratory or infectious disease causes and emergency room visits.ConclusionImplementing HCU-based monitoring systems in small areas deserves further investigations as it could facilitate the containment of COVID-19 and other unknown infectious diseases in the future.

Increased risk of myocarditis and pericarditis and reduced likelihood of severe clinical outcomes associated with COVID-19 vaccination: a cohort study in Lombardy, Italy.

INTRODUCTION: We aimed to assess harms (post-vaccine myocarditis and pericarditis) and benefits (preventing severe disease) of COVID-19 vaccination. METHODS: We conducted a population-based retrospective cohort study. Using the integrated platform of the vaccination campaign of Lombardy Region (Italy), after the exclusion of 24,188 individuals not beneficiaries of the Regional Health Service, 9,184,146 citizens candidates to vaccine at December 27, 2020 were followed until November 30, 2021 (the loss to follow-up rate was 0.5%). From the date of administration of each vaccine dose to day 28 post-administration, three periods that covered exposure to the first, second, and third dose were defined. The benefit-risk profile of vaccines was performed by comparing the number needed to harm (NNH) and number needed to treat (NNT) by sex, age, and vaccine type. RESULTS: Incidence rates of myocarditis were 9.9 and 5.2 per million person-months during the exposure and no-exposure periods, respectively, and the incidence rates of pericarditis were 19.5 and 15.9 per million person-months, respectively. The risk of myocarditis was highest following exposure to the second dose of the Moderna vaccine (adjusted HR: 5.5, 95% CI: 3.7 to 8.1). Exposure to the Moderna vaccine was also associated with an increased risk of pericarditis (adjusted HR 2.2, 1.5 to 3.1). NNT was higher than NNH (9471 vs. 7213) for 16 to 19-year-old men who received the Moderna vaccine, while all other sex, age, and vaccine subgroups had a favourable harm-benefit profile. CONCLUSIONS: Men 16 to 19 years of age has the highest rates of myocarditis within a few days after receiving the Moderna vaccines. The balance between harms and benefits was almost always in favour of vaccination.

Early Detection of SARS-CoV-2 Epidemic Waves: Lessons from the Syndromic Surveillance in Lombardy, Italy.

We evaluated the performance of the exponentially weighted moving average (EWMA) model for comparing two families of predictors (i.e., structured and unstructured data from visits to the emergency department (ED)) for the early detection of SARS-CoV-2 epidemic waves. The study included data from 1,282,100 ED visits between 1 January 2011 and 9 December 2021 to a local health unit in Lombardy, Italy. A regression model with an autoregressive integrated moving average (ARIMA) error term was fitted. EWMA residual charts were then plotted to detect outliers in the frequency of the daily ED visits made due to the presence of a respiratory syndrome (based on coded diagnoses) or respiratory symptoms (based on free text data). Alarm signals were compared with the number of confirmed SARS-CoV-2 infections. Overall, 150,300 ED visits were encoded as relating to respiratory syndromes and 87,696 to respiratory symptoms. Four strong alarm signals were detected in March and November 2020 and 2021, coinciding with the onset of the pandemic waves. Alarm signals generated for the respiratory symptoms preceded the occurrence of the first and last pandemic waves. We concluded that the EWMA model is a promising tool for predicting pandemic wave onset.

Factors associated with severe or fatal clinical manifestations of SARS-CoV-2 infection after receiving the third dose of vaccine.

BACKGROUND: Little is known about vulnerability to severe COVID-19 illness after vaccination completion with three doses of vaccine against COVID-19. OBJECTIVES: To identify individual features associated with increased risk of severe clinical manifestation of SARS-CoV-2 infections after receiving the third dose of vaccine against COVID-19. METHODS: We performed a nested case-control study based on 3,360,116 citizens from Lombardy, Italy, aged 12 years or older who received the third dose of vaccine against COVID-19 from 20 September through 31 December 2021. Individuals were followed from 14 days after vaccination completion until the occurrence of severe COVID-19 illness, death unrelated to COVID-19, emigration or 15 March 2022. For each case, controls were randomly selected to be 1:10 matched for the date of vaccination completion and municipality of residence. The association between candidate predictors and outcome was assessed through multivariable conditional logistic regression models. RESULTS: During 12,538,330 person-months of follow-up, 5171 cases of severe illness occurred. As age increased, a trend towards increasing odds of severe illness was observed. Male gender was a significant risk factor. As the number of contacts with the Regional Health Service increased, a trend towards increasing odds of severe illness was observed. Having had a previous SARS-CoV-2 infection was a significant protective factor. Having received the Moderna vaccine significantly decreased the odds of severe illness. Significant higher odds were associated with 42 diseases/conditions. Odds ratios ranged from 1.23 (diseases of the musculoskeletal system) to 5.00 (autoimmune disease). CONCLUSIONS: This study provides useful insights for establishing priority in fourth-dose vaccination programs.

Access to SARS-CoV-2 diagnostic tests: are there barriers for the immigrants in Italy?

OBJECTIVES: to describe the epidemiology of SARS-CoV-2 infection in relation with the use of nasal swabs in the immigrant population in Italy, using data from the COVID-19 national surveillance system and to verify if a difference is present comparing natives and immigrant. DESIGN: descriptive study based on longitudinal health-administrative data. SETTING AND PARTICIPANTS: general population of six Italian Regions (Piedmont, Lombardy, Veneto, Emilia-Romagna, Tuscany, Lazio) covering about 55% of the resident population and 72% of foreigners' population. MAIN OUTCOME MEASURES: regional rates of access to at least a nasal swab, separately by country of origin. RESULTS: across all the periods, a lower rate in the foreigners' group was observed, with the only exception of the period May-June 2021. Considering separately High Migratory Pressure Countries (HMPCs) and Highly Developed Countries (HDCs), a higher proportion of nasal swabs performed in people coming from HDC with respect to HMPCs and natives was noticed. This observation is consistent in males and females. CONCLUSIONS: during the first wave of the pandemic, Italians have had a higher proportion of nasal swabs compared to migrants across all Regions. This difference disappeared in the following periods, probably due to a major availability of diagnostic tests.

Postmarketing active surveillance of myocarditis and pericarditis following vaccination with COVID-19 mRNA vaccines in persons aged 12 to 39 years in Italy: A multi-database, self-controlled case series study.

BACKGROUND: Myocarditis and pericarditis following the Coronavirus Disease 2019 (COVID-19) mRNA vaccines administration have been reported, but their frequency is still uncertain in the younger population. This study investigated the association between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccines, BNT162b2, and mRNA-1273 and myocarditis/pericarditis in the population of vaccinated persons aged 12 to 39 years in Italy. METHODS AND FINDINGS: We conducted a self-controlled case series study (SCCS) using national data on COVID-19 vaccination linked to emergency care/hospital discharge databases. The outcome was the first diagnosis of myocarditis/pericarditis between 27 December 2020 and 30 September 2021. Exposure risk period (0 to 21 days from the vaccination day, subdivided in 3 equal intervals) for first and second dose was compared with baseline period. The SCCS model, adapted to event-dependent exposures, was fitted using unbiased estimating equations to estimate relative incidences (RIs) and excess of cases (EC) per 100,000 vaccinated by dose, age, sex, and vaccine product. Calendar period was included as time-varying confounder in the model. During the study period 2,861,809 persons aged 12 to 39 years received mRNA vaccines (2,405,759 BNT162b2; 456,050 mRNA-1273); 441 participants developed myocarditis/pericarditis (346 BNT162b2; 95 mRNA-1273). Within the 21-day risk interval, 114 myocarditis/pericarditis events occurred, the RI was 1.99 (1.30 to 3.05) after second dose of BNT162b2 and 2.22 (1.00 to 4.91) and 2.63 (1.21 to 5.71) after first and second dose of mRNA-1273. During the [0 to 7) days risk period, an increased risk of myocarditis/pericarditis was observed after first dose of mRNA-1273, with RI of 6.55 (2.73 to 15.72), and after second dose of BNT162b2 and mRNA-1273, with RIs of 3.39 (2.02 to 5.68) and 7.59 (3.26 to 17.65). The number of EC for second dose of mRNA-1273 was 5.5 per 100,000 vaccinated (3.0 to 7.9). The highest risk was observed in males, at [0 to 7) days after first and second dose of mRNA-1273 with RI of 12.28 (4.09 to 36.83) and RI of 11.91 (3.88 to 36.53); the number of EC after the second dose of mRNA-1273 was 8.8 (4.9 to 12.9). Among those aged 12 to 17 years, the RI was of 5.74 (1.52 to 21.72) after second dose of BNT162b2; for this age group, the number of events was insufficient for estimating RIs after mRNA-1273. Among those aged 18 to 29 years, the RIs were 7.58 (2.62 to 21.94) after first dose of mRNA-1273 and 4.02 (1.81 to 8.91) and 9.58 (3.32 to 27.58) after second dose of BNT162b2 and mRNA-1273; the numbers of EC were 3.4 (1.1 to 6.0) and 8.6 (4.4 to 12.6) after first and second dose of mRNA-1273. The main study limitations were that the outcome was not validated through review of clinical records, and there was an absence of information on the length of hospitalization and, thus, the severity of the outcome. CONCLUSIONS: This population-based study of about 3 millions of residents in Italy suggested that mRNA vaccines were associated with myocarditis/pericarditis in the population younger than 40 years. According to our results, increased risk of myocarditis/pericarditis was associated with the second dose of BNT162b2 and both doses of mRNA-1273. The highest risks were observed in males of 12 to 39 years and in males and females 18 to 29 years vaccinated with mRNA-1273. The public health implication of these findings should be considered in the light of the proven mRNA vaccine effectiveness in preventing serious COVID-19 disease and death.

[The impact of the COVID-19 pandemic on the Italian and foreign population in the various phases: the results of an interregional multicentre project]. / L'impatto della pandemia di COVID-19 nella popolazione italiana e straniera residente nelle diverse fasi: i risultati di un progetto multicentrico inter-regionale.

OBJECTIVES: to analyze the difference of the SARS-CoV-2 infection impact between Italian and foreigner subjects, evaluating the trend of infections and access to diagnostic tests (molecular or antigenic swabs for the detection of SARS- CoV-2) in the two different populations, inducing the detection of new positive cases in the population. DESIGN: retrospective population study for the period February 2020-June 2021. SETTING AND PARTICIPANTS: Italian and foreign resident population on 1st January of the years 2020 and 2021 in the Regions participating to the project: Piedmont, Lombardy, Veneto, Emilia-Romagna (Northern Italy), Tuscany, Lazio (Central Italy), and Sicily (Southern Italy). MAIN OUTCOME MEASURES: in the two populations, for every week and aggregated by macropandemic period were calculated: • the test rate (people tested on the population); • the swab positivity rate (positive subjects on those who are tested); • the new positives (positive subjects on study population); • the percentage of foreigners among the new positive cases. The ratio of the value of the indicators in the foreign and Italian populations (with 95% confidence interval) was calculated to evaluate the association between nationality (Italian vs not Italian) and outcome. The analyses were conducted at the regional level and at pool level. RESULTS: the trend of new positives by nationality (Italian vs not Italian) has a similar tendency in the different pandemic waves. However, the incidence of new positives during pandemic waves among foreigners is lower than in Italians, while it tends to increase during intermediate periods. Except for the summer periods, foreigners are less tested than Italians, but the percentage of new positives out of the total of new ones tested is higher among foreigners compared to Italians. The relative weight of new positives among foreigners tends to increase in periods with the greatest risk of inflow of SARS-CoV-2 for foreigners. CONCLUSIONS: the epidemic trends in the two populations are similar, although foreigners tend to show lower incidence values, probably in part because they are tested less frequently. Furthermore, in foreigners compared to Italians, there is a greater risk of contracting SARS-CoV-2 infection, especially in periods of relaxation of containment Coronavirus measures, reopening of national borders, production and commercial activities.

[Mortality and impact of COVID-19 by citizenship in seven Italian Regions from the beginning of the pandemic to mid-July 2021]. / Mortalità per COVID-19 nella popolazione immigrata in sette Regioni italiane da inizio pandemia a metà luglio 2021.

OBJECTIVES: to quantify the variability of COVID-19 mortality from the beginning of the pandemic to mid-July 2021, in relation to the immigrant status and by Region and period. DESIGN: observational incidence study. SETTING AND PARTICIPANTS: the study population consists of the residents at the beginning of 2020 in seven Regions (Piedmont, Lombardy, Veneto, Emilia-Romagna, Tuscany, Lazio, Sicily) aged <=74 years. MAIN OUTCOME MEASURES: absolute frequency of deaths occurred in subjects who tested positive for SARS-CoV-2, crude and standardized rates (standard: Italian population at the beginning of 2020), and mortality rates ratios (obtained using Poisson models), by immigrant status and stratified by gender, Region of residence, and period. The study period was divided into 5 subperiods: 22.02.2020-25.05.2020, 26.05.2020-02.10.2020, 03.10.2020-26.02.2021, 27.02.2021-16.07.2021. RESULTS: the study includes more than one half of the Italian population and most of the immigrants residing in the country, who are younger than Italians and experienced fewer COVID-19 deaths. Deaths among those who tested positive varied greatly between Regions and periods; standardized rates showed considerable increases over time among immigrants. In terms of rate ratios, there were excesses among immigrant males in the third period (MRR: 1.46; 95%CI 1.30-1.65) and in the fourth period (MRR: 1.55; 95%CI 1, 34-1.81). Among immigrant females, there is an indication of lower risk in the third period (MRR: 0.79; 95%CI 0.65-0.97) and of greater risk in the fourth period (MRR: 1. 46; 95%CI 1.21-1.77). Finally, the effect is modified by the Region of residence, both in the third and in the fourth period for males and only in the fourth period for females. CONCLUSIONS: the risk of premature mortality due to COVID-19 is linked to immigrant status and with an intensity that varies by gender, Region, and period. More accessible tools for prevention, diagnosis and early healthcare can support immigrant communities in managing the risk factors linked to the spread of infections and, in particular, counteract their evolution into more severe disease outcomes.

[SARS-CoV-2 epidemic among Italians e resident immigrant population: differential incidence from an interregional multicentre study]. / L'epidemia di SARS-CoV-2 nella popolazione italiana e straniera: differenze di incidenza che emergono da uno studio multicentrico interregionale.

OBJECTIVES: to describe differences in the incidence of SARS-CoV-2 infections between Italians and foreigners residing in seven Italian Regions during the different phases of the pandemic and by gender. DESIGN: retrospective observational study. SETTING AND PARTICIPANTS: all confirmed SARS-CoV-2 infections from 02.02. 2020 to 16.07.2021 in the seven Regions under study were included. Italian resident population calculated by the National Institute of Statistics as of 01.01.2020 was used to calculate the rates. The considered period is divided into 5 sub-periods (phases). MAIN OUTCOME MEASURES: number of confirmed SARS-CoV-2 infections in the five phases of the pandemic and crude rates by citizenship (Italian vs foreign). Distribution of infections by age group and by week. Crude and age-adjusted incidence rates ratios (IRR) were calculated, by Region, gender, and phase of the pandemic. RESULTS: an epidemic curve delay was observed in foreigners in the first phase of the epidemic, in particular in the northern Regions, the most affected in that phase. The first phase of the epidemic was characterized by a greater proportion of cases occurred in people aged over 60 years than the other phases, both in Italians and in foreigners. The incidence among foreigners is higher during the summer of 2020 (intermediate period: June-September 2020) and during the last period (May-July 2021) in all Regions. The overall figure shows a lower incidence among foreigners than Italians, except for males in Tuscany. CONCLUSIONS: the lower incidence rates among foreigners should be interpreted with caution as the available data suggest that it is at least partly attributable to less access to diagnostic tests. Regional differences found in the study deserve further research together with the effect of gender and country of origin.

Vulnerability Predictors of Post-Vaccine SARS-CoV-2 Infection and Disease-Empirical Evidence from a Large Population-Based Italian Platform.

We aimed to identify individual features associated with increased risk of post-vaccine SARS-CoV-2 infection and severe COVID-19 illness. We performed a nested case-control study based on 5,350,295 citizens from Lombardy, Italy, aged ≥ 12 years who received a complete anti-COVID-19 vaccination from 17 January 2021 to 31 July 2021, and followed from 14 days after vaccine completion to 11 November 2021. Overall, 17,996 infections and 3023 severe illness cases occurred. For each case, controls were 1:1 (infection cases) or 1:10 (severe illness cases) matched for municipality of residence and date of vaccination completion. The association between selected predictors (sex, age, previous occurrence of SARS-CoV-2 infection, type of vaccine received, number of previous contacts with the Regional Health Service (RHS), and the presence of 59 diseases) and outcomes was assessed by using multivariable conditional logistic regression models. Sex, age, previous SARS-CoV-2 infection, type of vaccine and number of contacts with the RHS were associated with the risk of infection and severe illness. Moreover, higher odds of infection and severe illness were significantly associated with 14 and 34 diseases, respectively, among those investigated. These results can be helpful to clinicians and policy makers for prioritizing interventions.