Impact of antibiotic prophylaxis in second-stage surgery in joint prosthesis infection treated with two-stage exchange. A multicenter case-control study.

INTRODUCTION: After two-stage exchange due to prosthetic joint infection (PJI), the new prosthesis carries a high risk of reinfection (RePJI). There isn`t solid evidence regarding the antibiotic prophylaxis in 2nd-stage surgery. The objective of this study is to describe what antibiotic prophylaxis is used in this surgery and evaluate its impact on the risk of developing RePJI. METHODS: Retrospective multicenter case-control study in Spanish hospitals. The study included cases of PJI treated with two-stage exchange and subsequently developed a new infection. For each case, two controls were included, matched by prosthesis location, center, and year of surgery. The prophylaxis regimens were grouped based on their antibacterial spectrum, and we calculated the association between the type of regimen and the development of RePJI using conditional logistic regression, adjusted for possible confounding factors. RESULTS: We included 90 cases from 12 centers, which were compared with 172 controls. The most frequent causative microorganism was Staphylococcus epidermidis with 34 cases (37.8%). Staphylococci were responsible for 50 cases (55.6%), 32 of them (64%) methicillin-resistant. Gram-negative bacilli were involved in 30 cases (33.3%), the most common Pseudomonas aeruginosa. In total, 83 different antibiotic prophylaxis regimens were used in 2nd-stage surgery, the most frequent a single preoperative dose of cefazolin (48 occasions; 18.3%); however, it was most common a combination of a glycopeptide and a beta-lactam with activity against Pseudomonas spp (99 cases, 25.2%). In the adjusted analysis, regimens that included antibiotics with activity against methicillin-resistant staphylococci AND Pseudomonas spp were associated with a significantly lower risk of RePJI (adjusted OR = 0.24; 95% IC: 0.09-0.65). CONCLUSIONS: The lack of standardization in 2nd-satge surgery prophylaxis explains the wide diversity of regimens used in this procedure. The results suggest that antibiotic prophylaxis in this surgery should include an antibiotic with activity against methicillin-resistant staphylococci and Pseudomonas.

Development and Validation of Case-Finding Algorithms for Digestive Cancer in the Spanish Healthcare Database BIFAP.

BACKGROUND: electronic health records (EHRs) are helpful tools in epidemiology despite not being primarily collected for research. In Spain, primary care physicians play a central role and manage patients even in specialized care. All of this introduces variability that may lead to diagnostic inconsistencies. Therefore, data validation studies are crucial, so we aimed to develop and validate case-finding algorithms for digestive cancer in the primary care database BIFAP. METHODS: from 2001 to 2019, subjects aged 40-89 without a cancer history were included. Case-finding algorithms using diagnostic codes and text-mining were built. We randomly sampled, clustered, and manually reviewed 816 EHRs. Then, positive predictive values (PPVs) and 95% confidence intervals (95% CIs) for each cancer were computed. Age and sex standardized incidence rates (SIRs) were compared with those reported by the National Cancer Registry (REDECAN). RESULTS: we identified 95,672 potential cases. After validation, the PPV (95% CI) for hepato-biliary cancer was 87.6% (81.8-93.4), for esophageal cancer, it was 96.2% (93.1-99.2), for pancreatic cancer, it was 89.4% (84.5-94.3), for gastric cancer, it was 92.5% (88.3-96.6), and for colorectal cancer, it was 95.2% (92.1-98.4). The SIRs were comparable to those reported by the REDECAN. CONCLUSIONS: the case-finding algorithms demonstrated high performance, supporting BIFAP as a suitable source of information to conduct epidemiologic studies of digestive cancer.

Risk of ischaemic stroke among new users of glucosamine and chondroitin sulphate: a nested case-control study.

Background: Several studies have reported that the use of chondroitin sulphate (CS) and glucosamine may reduce the risk of acute myocardial infarction. Although it is thought that this potential benefit could be extended to ischaemic stroke (IS), the evidence is scarce. Objective: To test the hypothesis that the use of prescription glucosamine or CS reduces the risk of IS. Design: Case-control study nested in an open cohort. Methods: Patients aged 40-99 years registered in a Spanish primary healthcare database (BIFAP) during the 2002-2015 study period. From this cohort, we identified incident cases of IS, applying a case-finding algorithm and specific validation procedures, and randomly sampled five controls per case, individually matched with cases by exact age, gender and index date. Adjusted odds ratios (AORs) and 95% confidence interval (CI) were computed through a conditional logistic regression. Only new users of glucosamine or CS were considered. Results: A total of 13,952 incident cases of IS and 69,199 controls were included. Of them, 106 cases (0.76%) and 803 controls (1.16%) were current users of glucosamine or CS at index date, yielding an AOR of 0.66 (95% CI: 0.54-0.82) (for glucosamine, AOR: 0.55; 95% CI: 0.39-0.77; and for CS, AOR: 0.77; 95% CI: 0.60-0.99). The reduced risk among current users was observed in both sexes (men, AOR: 0.69; 95% CI: 0.49-0.98; women, AOR: 0.65; 95% CI: 0.50-0.85), in individuals above and below 70 years of age (AOR: 0.69; 95% CI: 0.53-0.89 and AOR: 0.59; 95% CI: 0.41-0.85, respectively), in individuals with vascular risk factors (AOR: 0.53; 95% CI: 0.39-0.74) and among current/recent users of nonsteroidal anti-inflammatory drugs (NSAIDs) (AOR: 0.71; 95% CI: 0.55-0.92). Regarding duration, the reduced risk was observed in short-term users (<365 days, AOR: 0.61; 95% CI: 0.48-0.78) while faded and became nonsignificant in long-term users (>364 days AOR: 0.86; 95% CI: 0.57-1.31). Conclusions: Our results support a protective effect of prescription CS and glucosamine in IS, which was observed even in patients at vascular risk. Mini abstract: Our aim was to analyse whether the use of glucosamine or chondroitin sulphate (CS) reduces the risk of ischaemic stroke (IS). We detected a significant decrease.

Statins and Colorectal Cancer Risk: A Population-Based Case-Control Study and Synthesis of the Epidemiological Evidence.

(1) Background: The pleiotropic effects of statins may explain a chemoprotective action against colorectal cancer (CRC). Many studies have tested this hypothesis, but results have been inconsistent so far. Moreover, few have examined statins individually which is important for determining whether there is a class effect and if lipophilicity and intensity may play a role. (2) Methods: From 2001-2014, we carried out a study comprised of 15,491 incident CRC cases and 60,000 matched controls extracted from the primary healthcare database BIFAP. We fit a logistic regression model to compute the adjusted-odds ratios (AOR) with their 95% confidence intervals (CIs). Additionally, we carried out a systematic review and meta-analysis. (3) Results: Current use of statins showed a reduced risk of CRC (AOR = 0.87; 95% CI: 0.83-0.91) not sustained after discontinuation. The association was time-dependent, starting early (AOR6months-1year = 0.85; 95% CI: 0.76-0.96) but weakened beyond 3-years. A class effect was suggested, although only significant for simvastatin and rosuvastatin. The risk reduction was more marked among individuals aged 70 or younger, and among moderate-high intensity users. Forty-eight studies were included in the meta-analysis (pooled-effect-size = 0.90; 95% CI: 0.86-0.93). (4) Conclusions: Results from the case-control study and the pooled evidence support a moderate chemoprotective effect of statins on CRC risk, modified by duration, intensity, and age.

Selective Serotonin Reuptake Inhibitors and Risk of Noncardioembolic Ischemic Stroke: A Nested Case-Control Study.

BACKGROUND: Multiple studies have reported that the use of selective serotonin reuptake inhibitors (SSRIs) is associated with an increased risk of ischemic stroke; however, this finding may be the result of a confounding by indication. We examined the association using different approaches to minimize such potential bias. METHODS: A nested case-control study was carried out in a Spanish primary health-care database over the study period 2001 to 2015. Cases were patients sustaining an ischemic stroke with no sign of cardioembolic or unusual cause. For each case, up to 5 matched controls (for exact age, sex, and index date) were randomly selected. Antidepressants were divided in 6 pharmacological subgroups according to their mechanism of action. The current use of SSRIs (use within a 30-day window before index date) was compared with nonuse, past use (beyond 365 days) and current use of other antidepressants through a conditional logistic regression model to obtain adjusted odds ratios and 95% CI. Only initiators of SSRIs and other antidepressants were considered. RESULTS: A total of 8296 cases and 37 272 matched controls were included. Of them, 255 (3.07%) were current users of SSRIs among cases and 834 (2.24%) among controls, yielding an adjusted odds ratio of 1.14 (95% CI, 0.97-1.34) as compared with nonusers, 0.94 (95% CI, 0.77-1.13) as compared with past-users and 0.74 (95% CI, 0.58-0.93) as compared with current users of other antidepressants. No relevant differences were found by duration (≤1, >1 year), sex, age (<70, ≥70 years old) and background vascular risk. CONCLUSIONS: The use of SSRIs was not associated with an increased risk of noncardioembolic ischemic stroke. On the contrary, as compared with other antidepressants, SSRIs appeared to be protective.

Influenza vaccine and risk of acute myocardial infarction in a population-based case-control study.

OBJECTIVE: To assess the relationship between influenza vaccination and risk of a first acute myocardial infarction (AMI) in the general population by different epidemic periods. METHODS: This is a population-based case-control study carried out in BIFAP (Base de datos para la investigación farmacoepidemiológica en atención primaria), over 2001-2015, in patients aged 40-99 years. Per each incident AMI case, five controls were randomly selected, individually matched for exact age, sex and index date (AMI diagnosis). A patient was considered vaccinated when he/she had a recorded influenza vaccination at least 14 days before the index date within the same season. The association between influenza vaccination and AMI risk was assessed through a conditional logistic regression, computing adjusted ORs (AOR) and their respective 95% CIs. The analysis was performed overall and by each of the three time epidemic periods per study year (pre-epidemic, epidemic and postepidemic). RESULTS: We identified 24 155 AMI cases and 120 775 matched controls. Of them, 31.4% and 31.2%, respectively, were vaccinated, yielding an AOR of 0.85 (95% CI 0.82 to 0.88). No effect modification by sex, age and background cardiovascular risk was observed. The reduced risk of AMI was observed shortly after vaccination and persisted over time. Similar results were obtained during the pre-epidemic (AOR=0.87; 95% CI 0.79 to 0.95), epidemic (AOR=0.89; 95% CI 0.82 to 0.96) and postepidemic (AOR=0.83; 95% CI 0.79 to 0.87) periods. No association was found with pneumococcal vaccine (AOR=1.10; 95% CI 1.06 to 1.15). CONCLUSIONS: Results are compatible with a moderate protective effect of influenza vaccine on AMI in the general population, mostly in primary prevention, although bias due to unmeasured confounders may partly account for the results.