Background Concerns have been raised about the possibility that inhibitors of the renin-angiotensin-aldosterone system (RAAS) could predispose individuals to severe COVID-19; however, epidemiological evidence is lacking. We report the results of a case-population study done in Madrid, Spain, since the outbreak of COVID-19.Methods In this case-population study, we consecutively selected patients aged 18 years or older with a PCRconfirmed diagnosis of COVID-19 requiring admission to hospital from seven hospitals in Madrid, who had been admitted between March 1 and March 24, 2020. As a reference group, we randomly sampled ten patients per case, individually matched for age, sex, region (ie, Madrid), and date of admission to hospital (month and day; index date), from Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP), a Spanish primary health-care database, in its last available year (2018). We extracted information on comorbidities and prescriptions up to the month before index date (ie, current use) from electronic clinical records of both cases and controls. The outcome of interest was admission to hospital of patients with COVID-19. To minimise confounding by indication, the main analysis focused on assessing the association between COVID-19 requiring admission to hospital and use of RAAS inhibitors compared with use of other antihypertensive drugs. We calculated odds ratios (ORs) and 95% CIs, adjusted for age, sex, and cardiovascular comorbidities and risk factors, using conditional logistic regression. The protocol of the study was registered in the EU electronic Register of Post-Authorisation Studies, EUPAS34437.Findings We collected data for 1139 cases and 11 390 population controls. Among cases, 444 (39•0%) were female and the mean age was 69•1 years (SD 15•4), and despite being matched on sex and age, a significantly higher proportion of cases had pre-existing cardiovascular disease (OR 1•98, 95% CI 1•62-2•41) and risk factors (1•46, 1•23-1•73) than did controls. Compared with users of other antihypertensive drugs, users of RAAS inhibitors had an adjusted OR for COVID-19 requiring admission to hospital of 0•94 (95% CI 0•77-1•15). No increased risk was observed with either angiotensin-converting enzyme inhibitors (adjusted OR 0•80, 0•64-1•00) or angiotensin-receptor blockers (1•10, 0•88-1•37). Sex, age, and background cardiovascular risk did not modify the adjusted OR between use of RAAS inhibitors and COVID-19 requiring admission to hospital, whereas a decreased risk of COVID-19 requiring admission to hospital was found among patients with diabetes who were users of RAAS inhibitors (adjusted OR 0•53, 95% CI 0•34-0•80). The adjusted ORs were similar across severity degrees of COVID-19.Interpretation RAAS inhibitors do not increase the risk of COVID-19 requiring admission to hospital, including fatal cases and those admitted to intensive care units, and should not be discontinued to prevent a severe case of COVID-19.Funding Instituto de Salud Carlos III.

Several immunomodulatory agents are used in the treatment of epidermal necrolysis, but evidence of their efficacy is limited. The Autonomous Community of Madrid has two reference burn units to which all patients with epidermal necrolysis are referred. One burn unit has mostly used cyclosporine (CsA), and the other has used non-CsA therapies (mainly high-dose intravenous immunoglobulin). The allocation of patients to one or the other burn unit was mainly based on proximity, resembling a random assignment. Thus, we took advantage of this "natural experiment" to estimate the mortality risk ratio (MRR) of CsA (n = 26) compared with non-CsA (n = 16) treatment using hospital as an instrumental variable over the period from 2001 to 2015. We also computed the observed versus expected (O/E) MRR in a case series of 49 CsA-treated patients (including 23 patients from other regions treated in Madrid), and using the Score for Toxic Epidermal Necrolysis (i.e., SCORTEN) scale to estimate the expected values. The instrumental variable-based MRR of CsA versus non-CsA was 0.09 (95% confidence interval = 0.00-0.49). The O/E analysis also showed a reduction in mortality risk (MRR = 0.42; 95% confidence interval = 0.14-0.99). We identified five other case series of CsA-treated patients providing MRR and meta-analyzed their results. The pooled MRR (including from this study) was 0.41 (95% confidence interval = 0.21-0.80). All three approaches consistently show that CsA reduces the mortality in epidermal necrolysis patients.

BACKGROUND & AIMS:The antiplatelet effect of low-dose aspirin, via inhibition of cyclooxygenase-1, might contribute to its ability to reduce the risk of colorectal cancer (CRC). Antiplatelet agents with a different mechanism, such as clopidogrel, might have the same effects. We aimed to quantify the effects of low-dose aspirin and clopidogrel on the risk of CRC in a Mediterranean population. METHODS:We performed a nested case-control study using a primary care database (Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria) in Spain. We collected data, from 2001 through 2014, on 15,491 incident cases of CRC and 60,000 randomly selected individuals (controls), frequency-matched to cases by age, sex, and year. To estimate the association between exposure to different antiplatelet agents and the risk of colorectal cancer, we built multiple logistic regression models and computed the adjusted-odds ratios (AORs) and their respective 95% CIs. RESULTS:Use of low-dose aspirin was associated with a reduced risk of CRC overall (AOR, 0.83; 95% CI, 0.78-0.89) and in patients receiving treatment for more than 1 year (AOR, 0.79; 95% CI, 0.73-0.85). Use of clopidogrel was associated with a decreased risk of CRC overall (AOR, 0.8; 95% CI, 0.69-0.93) and in patients receiving treatment for more than 1 year (AOR, 0.65; 95% CI, 0.55-0.78). Dual antiplatelet therapy had the same effect as either drug taken as monotherapy. No modification by sex or age was observed. CONCLUSIONS:In a nested case-control study of a primary care database in Spain, we found clopidogrel use, alone or in combination with low-dose aspirin, to reduce the risk of CRC by 20% to 30%, a magnitude similar to that of low-dose aspirin alone. These data support the concept that inhibiting platelets is an effective strategy for prevention of CRC.