Decline and uneven recovery from 7 common long-term conditions managed in the Catalan primary care after two pandemic years: an observational retrospective population-based study using primary care electronic health records (preprint)

Background: The incidence of chronic diseases during the COVID-19 pandemic has drastically been reduced worldwide due to disruptions in healthcare systems. The aim of our study is to analyse the trends in the incidence of 7 commonly managed primary care chronic diseases during the last 2 years of the COVID-19 pandemic in Catalonia. Methods We performed an observational retrospective population-based study using data from primary care electronic health records from January 2018 to August 2022 (5.1 million people over 14 years). We divided the study period into two: a pre-pandemic period (before 14 March 2020) and a pandemic period. We performed a segmented regression analysis of daily incidence rates per 100,000 inhabitants of 7 chronic diseases: type 2 diabetes mellitus (T2DM), asthma, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), heart failure (HF), hypertension and hypercholesterolemia. In addition, we compared annual incidence between pandemic years (2020, 2021 and 2022) and 2019. Associated incidence rate ratios (IRR) were also calculated. Finally, we estimated the number of expected diagnoses during the pandemic period using data from 2019 and we compared it with the observed data. Results We analysed 740,820 new chronic diseases’ diagnoses. Daily incidence rates of all 7 chronic diseases were drastically interrupted on 14 March 2020, and a general upward trend was observed during the following months. Reductions in 2020 were around 30% for all conditions except COPD which had greater reductions (IRR: 0.58 [95% CI: 0.57 to 0.6]) and HF with lesser drops (IRR: 0.86 [95% CI: 0.84 to 0.88]). Some of the chronic conditions have returned to pre-pandemic diagnosis levels, except asthma, COPD and IHD. The return to pre-pandemic diagnosis levels compensated for the drops in 2020 for T2DM and HF, but not for hypertension which presented an incomplete recovery. We also observed an excess of hypercholesterolemia diagnoses of 8.5% (95%CI: 1.81–16.15%). Conclusions Although primary care has recovered the pre-pandemic diagnosis levels for some chronic diseases, there are still missing diagnoses of asthma, COPD and IHD that should be addressed.

Increase of scabies infestations during the COVID-19 pandemic in Catalonia (preprint)

During the COVID-19 pandemic, several clinicians in Spain reported an increase in scabies diagnoses. We performed a time-series analysis with data from 2014 to 2022 to quantify this increase. We found an increasing trend during late 2020 and 2021, peaking in March 2022 with an almost 4.5-fold incidence than expected, especially in those aged between 16 and 30 years. Although scabies is more frequent in most socioeconomic deprived areas, the observed rise occurs in all the areas. We recommend increasing surveillance among other countries to detect unexpected increases in scabies outbreaks.

Cancer diagnosis in primary care after second pandemic year in Catalonia: a time-series analysis of primary care electronic health records covering about five million people (preprint)

Background During COVID-19 pandemic, incidence of chronic disease had drastically been reduced due to health care interruptions. The aim of this study is to analyze cancer diagnosis during the two years of the COVID-19 pandemic. Methods Time-series study of malignant neoplasms, using data from the primary care electronic health records from January 2014 to December 2021. We obtained the expected monthly incidence using a temporary regression adjusted by trend and seasonality. We additionally compared cancer incidence in 2019 with those of 2020 and 2021 using the T-Test. We performed analysis globally, by sex and by type of cancer. Results During 2020, the incidence of cancer had reduced by -21% compared to 2019 (p-value <0.05). Greater reductions were observed during lockdown in early 2020 (>40%) and with some types of cancers, especially prostate and skin cancers (−29.6% and -26.9% respectively, p-value<0.05). Lung cancers presented statistically non-significant reductions in both years. Cancer diagnosis returned to expected around March 2021, and incidence in 2021 was similar to that of 2019 (overall difference of 0.21%, p=0.967). However, -11% reduction still was found when comparing pandemic months of 2020-2021 with pre-pandemic months (2019-2020) Conclusions Although primary care cancer diagnostic capacity in 2021 has returned to pre-pandemic levels, missing diagnoses during the last two years have not been fully recovered. Key messages Cancer diagnoses have dramatically dropped during 2020 worldwide. We observe a -21% decline in 2020, but a return to pre-pandemic diagnosis capacity in 2021. A -11% outstanding drop was still found comparing pre-pandemic to pandemic months. Reductions were greater during the lockdown (>40%). Lung and breast cancers presented fewer reductions while prostate and skin cancers had greater drops. Missing diagnoses during the last two years have not been fully recovered

Comparative effectiveness and safety of homologous two-dose ChAdOx1 versus heterologous vaccination with ChAdOx1 and BNT162b2: a cohort analysis (preprint)

Small trials have suggested that heterologous vaccination with first-dose ChAdOx1 and second-dose BNT162b2 may generate a better immune response than homologous vaccination with two doses of ChAdOx1. We used linked data from Catalonia (Spain), where those aged <60 who received a first dose of ChAdOx1 could choose between ChAdOx1 and BNT162b2 for their second dose. Comparable cohorts were obtained after exact-matching 14,325/17,849 (80.3%) people receiving heterologous vaccination to 14,325/149,386 (9.6%) receiving homologous vaccination by age, sex, region, and date of second dose. Of these, 238 (1.7%) in the heterologous and 389 (2.7%) in the homologous groups developed COVID-19 between 1st June 2021 and 11th October 2021. The resulting hazard ratio (95% confidence interval) was 0.61 [ 0.52-0.71 ], favouring heterologous vaccination, with a Number Needed to Treat of 94.9 [ 71.8 - 139.8 ]. The two groups had similar testing rates and safety outcomes. Sensitivity and negative control outcome analyses confirmed these findings. In conclusion, we demonstrate that a heterologous vaccination schedule with ChAdOx1 followed by BNT162b2 was more efficacious than and similarly safe to homologous vaccination with two doses of ChAdOx1. Most of the infections in our study occurred when Delta was the predominant SARS-CoV-2 variant in Spain. These data agree with previous phase 2 randomised trials.

Non-differential risk of SARS-CoV-2 infection for members of polling stations on Catalan parliament voting day (preprint)

We aimed to assess the risk of SARS-CoV-2 infection for polling station members during the Catalan elections in February 2021. We compared the incidence 14 days after the elections between a cohort of polling station members (N= 18,304) and a control cohort paired by age, sex and place of residence. A total of 37 COVID-19 cases (0.2%) were confirmed in the members of the polling stations and 43 (0.23%) in the control group (p-value 0.576). Our study suggests that there was no greater risk of infection for the members of the polling stations.

Effects of BNT162b2 mRNA Vaccination on COVID-19 Disease, Hospitalisation and Mortality in Nursing Homes and Healthcare Workers: A Prospective Cohort Study Including 28,594 Nursing Home Residents, 26,238 Nursing Home Staff, and 61,951 Healthcare Workers in Catalonia (preprint)

Background: Spain began vaccinating priority groups against COVID-19 with BNT162b2 in late December 2020. We report associations of vaccination with COVID-19 infection, hospitalisation, and mortality among nursing home residents, nursing home staff, and healthcare workers. Methods: We analysed three cohorts of all nursing home residents, nursing home staff, and healthcare workers in Catalonia on 27 December 2020. Data were obtained from linked primary care, RT-PCR and lateral flow test, hospital, and mortality records. Those with a pre-study COVID-19 diagnosis or no linked electronic medical records were excluded. Two doses of BNT162b2 were administered 3 weeks apart. Participants were followed until the earliest of an outcome (confirmed COVID-19 infection, hospitalisation, and mortality) or 5 March 2021. Participants could contribute data to the unvaccinated, one-dose, and two-dose groups. Analyses were conducted using time-varying Cox regression. Multivariable adjustment for imbalances in socio-demographics, comorbidity, and polypharmacy. Findings: We included 28,594 nursing home residents, 26,238 nursing home staff, and 61,951 healthcare workers, of whom 2,405, 1,584, and 2,672 received COVID-19 diagnoses; 383, 35, and 76 were hospitalised; and 409, 0, and 1 died. The adjusted hazard ratio (HR) (95% confidence interval) for COVID-19 infection after two-dose vaccination was 0·08 (0·07-0·09) for nursing home residents, 0·12 (0·10-0·15) for nursing home staff, and 0·05 (0·04-0·07) for healthcare workers. The adjusted HRs for hospitalisation and mortality after two-dose vaccination were 0·03 (0·02-0·05) and 0·02 (0·01-0·03), respectively, for nursing home residents. Nursing home staff and healthcare workers recorded insufficient events for mortality analysis. Interpretation Vaccination was associated with 85%-96% reduction in SARS-CoV-2 infection in all three cohorts, and bigger reductions in hospitalisations and mortality amongst nursing home residents for up to two months. More data are needed on the long-term effects of COVID-19 vaccines. Funding: Partially supported by National Institute of Health Research UK, We do not have any other funding acknowledgements.Declaration of Interest: None to declare. Ethical Approval: The study was approved by the Clinical Research Ethics Committee of the IDIAP Jordi Gol with reference number 21/045-PCV.

Assessing the likelihood of contracting COVID-19 disease based on a predictive tree model: A retrospective cohort study.

BACKGROUND: Primary care is the major point of access in most health systems in developed countries and therefore for the detection of coronavirus disease 2019 (COVID-19) cases. The quality of its IT systems, together with access to the results of mass screening with Polymerase chain reaction (PCR) tests, makes it possible to analyse the impact of various concurrent factors on the likelihood of contracting the disease. METHODS AND FINDINGS: Through data mining techniques with the sociodemographic and clinical variables recorded in patient's medical histories, a decision tree-based logistic regression model has been proposed which analyses the significance of demographic and clinical variables in the probability of having a positive PCR in a sample of 7,314 individuals treated in the Primary Care service of the public health system of Catalonia. The statistical approach to decision tree modelling allows 66.2% of diagnoses of infection by COVID-19 to be classified with a sensitivity of 64.3% and a specificity of 62.5%, with prior contact with a positive case being the primary predictor variable. CONCLUSIONS: The use of a classification tree model may be useful in screening for COVID-19 infection. Contact detection is the most reliable variable for detecting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases. The model would support that, beyond a symptomatic diagnosis, the best way to detect cases would be to engage in contact tracing.