Laboratory-based surveillance of chronic kidney disease in people with private health coverage in Brazil.

BACKGROUND: Although approximately 25% of Brazilians have private health coverage (PHC), studies on the surveillance of chronic kidney disease (CKD) in this population are scarce. The objective of this study was to estimate the prevalence of CKD in individuals under two PHC regimes in Brazil, who total 8,335,724 beneficiaries. METHODS: Outpatient serum creatinine and proteinuria results of individuals from all five regions of Brazil, ≥ 18 years of age, and performed between 10/01/2021 and 10/31/2022, were analyzed through the own laboratory network database. People with serum creatinine measurements were evaluated for the prevalence and staging of CKD, and those with simultaneous measurements of serum creatinine and proteinuria were evaluated for the risk category of the disease. CKD was classified according to current guidelines and was defined as a glomerular filtration rate (GFR) < 60 ml/min/1.73 m² estimated by the 2021 CKD-EPI equation. RESULTS: The number of adults with serum creatinine results was 1,508,766 (age 44.0 [IQR, 33.9-56.8] years, 62.3% female). The estimated prevalence of CKD was 3.8% (2.6%, 0.8%, 0.2% and 0.2% in CKD stages 3a, 3b, 4 and 5, respectively), and it was higher in males than females (4.0% vs. 3.7%, p < 0.001, respectively) and in older age groups (0.2% among 18-29-year-olds, 0.5% among 30-44-year-olds, 2.0% among 45-59-year-olds, 9.4% among 60-74-year-olds, and 32.4% among ≥ 75-year-olds, p < 0.001) Adults with simultaneous results of creatinine and proteinuria were 64,178 (age 57.0 [IQR, 44.8-67.3] years, 58.1% female). After adjusting for age and gender, 70.1% were in the low-risk category of CKD, 20.0% were in the moderate-risk category, 5.8% were in the high-risk category, and 4.1% were in the very high-risk category. CONCLUSION: The estimated prevalence of CKD was 3.8%, and approximately 10% of the participants were in the categories of high or very high-risk of the disease. While almost 20% of beneficiaries with PHC had serum creatinine data, fewer than 1% underwent tests for proteinuria. This study was one of the largest ever conducted in Brazil and the first one to use the 2021 CKD-EPI equation to estimate the prevalence of CKD.

Development of an instrument to predict proliferative histological class in lupus nephritis based on clinical and laboratory data.

OBJECTIVES: To compare the correlations of histological class inferences based on clinical manifestations and laboratory tests between rheumatologists and nephrologists, to determine the associations of clinical and laboratory data with histological classes and to develop an instrument that can assist histological class identification in lupus nephritis (LN). METHODS: Retrospective study based on medical records of 80 systemic lupus erythematosus patients (SLICC criteria classification, 2012) who underwent kidney biopsy between 2010 and 2017. Two rheumatologists and two nephrologists received clinical and laboratory data and answered questions regarding which histological class was expected on kidney biopsy. Kappa (K) coefficient was used to assess agreement between evaluators. A decision tree was constructed using the chi-square interaction detector and logistic regression was performed for the development of the proliferative histological class predictor instrument. RESULTS: The mean age and disease duration were 33 ± 10.3 years and 11.5 ± 6.7 years, respectively. The level of agreement between the evaluators and kidney biopsy was poor (global K 0.364 ± 0.029; p < .001). Analyzing clinical and laboratory variables as predictors of proliferative histological class, patients with abnormal urinary sediment and positive anti-dsDNA antibodies presented 13.96 and 4.96 times higher risks of presenting class III or IV, respectively (p < 0.001). Our instrument has a sensitivity of 87.8% and specificity of 80%, using abnormal urinary sediment, anti-dsDNA antibodies, and serum creatinine as variables. CONCLUSIONS: Rheumatologists and nephrologists with experience in treating LN generated evaluations that correlated weakly with kidney biopsy. When kidney biopsy is unavailable or is contraindicated for medical reasons, instruments based on clinical and laboratory predictors may be helpful.

Symptoms for early diagnosis of chronic kidney disease in children - a machine learning-based score.

The objective of this study was to reveal the signs and symptoms for the classification of pediatric patients at risk of CKD using decision trees and extreme gradient boost models for predicting outcomes. A case-control study was carried out involving children with 376 chronic kidney disease (cases) and a control group of healthy children (n = 376). A family member responsible for the children answered a questionnaire with variables potentially associated with the disease. Decision tree and extreme gradient boost models were developed to test signs and symptoms for the classification of children. As a result, the decision tree model revealed 6 variables associated with CKD, whereas twelve variables that distinguish CKD from healthy children were found in the "XGBoost". The accuracy of the "XGBoost" model (ROC AUC = 0.939, 95%CI: 0.911 to 0.977) was the highest, while the decision tree model was a little lower (ROC AUC = 0.896, 95%CI: 0.850 to 0.942). The cross-validation of results showed that the accuracy of the evaluation database model was like that of the training. CONCLUSION: In conclusion, a dozen symptoms that are easy to be clinically verified emerged as risk indicators for chronic kidney disease. This information can contribute to increasing awareness of the diagnosis, mainly in primary care settings. Therefore, healthcare professionals can select patients for more detailed investigation, which will reduce the chance of wasting time and improve early disease detection. WHAT IS KNOWN: • Late diagnosis of chronic kidney disease in children is common, increasing morbidity. • Mass screening of the whole population is not cost-effective. WHAT IS NEW: • With two machine-learning methods, this study revealed 12 symptoms to aid early CKD diagnosis. • These symptoms are easily obtainable and can be useful mainly in primary care settings.

Prevalence and Determinants of Predialysis Dietitian Follow-Up: Results From the Brazilian Dialysis Registry.

OBJECTIVE: We aimed to evaluate the prevalence and sociodemographic determinants of predialysis dietitian follow-up in a large cohort of Brazilian dialysis patients. METHODS: We retrospectively evaluated data from all incident adult dialysis patients included in the Brazilian Dialysis Registry from January 2011 to September 2021. Predialysis dietitian follow-up was classified as present when a period more than 6 months of dietitian care was reported. Gender, age, skin color, education, body mass index, chronic kidney disease etiology, first chronic dialysis program, healthcare provider, and geographic regions were tested in logistic regression models. RESULTS: Ten thousand three hundred and eighty two patients met the inclusion criteria and 1,254 (12.1%) reported predialysis dietitian follow-up, most of them referred by a nephrologist (94.2%). The independent determinants of dietitian follow-up were older age, white skin color, higher education level, not having diabetes, living in North/Northeast and South (compared to Southeast), and having a nonpublic healthcare provider. When considered only patients under a predialysis care of a nephrologist, higher education, hemodialysis as the first dialysis modality, and living in the North/Northeast and South regions (compared with Southeast) were associated with dietitian follow-up. CONCLUSION: Predialysis dietitian follow-up for more than 6 months in a country where the public health system is the main dialysis provider is still very low. The nephrologist is pivotal for referral to dietitians but socioeconomic factors also seem to play a role in this regard.

Duplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments.

BACKGROUND: Carotid artery stenosis is an important cause of stroke and transient ischemic attack. Correctly and rapidly identifying patients with symptomatic carotid artery stenosis is essential for adequate treatment with early cerebral revascularization. Doubts about the diagnostic value regarding the accuracy of duplex ultrasound (DUS) and the possibility of using DUS as the single diagnostic test before carotid revascularization are still debated. OBJECTIVES: To estimate the accuracy of DUS in individuals with symptomatic carotid stenosis verified by either digital subtraction angiography (DSA), computed tomography angiography (CTA), or magnetic resonance angiography (MRA). SEARCH METHODS: We searched CRDTAS, CENTRAL, MEDLINE (Ovid), Embase (Ovid), ISI Web of Science, HTA, DARE, and LILACS up to 15 February 2021. We handsearched the reference lists of all included studies and other relevant publications and contacted experts in the field to identify additional studies or unpublished data. SELECTION CRITERIA: We included studies assessing DUS accuracy against an acceptable reference standard (DSA, MRA, or CTA) in symptomatic patients. We considered the classification of carotid stenosis with DUS defined with validated duplex velocity criteria, and the NASCET criteria for carotid stenosis measures on DSA, MRA, and CTA. We excluded studies that included < 70% of symptomatic patients; the time between the index test and the reference standard was longer than four weeks or not described, or that presented no objective criteria to estimate carotid stenosis. DATA COLLECTION AND ANALYSIS: The review authors independently screened articles, extracted data, and assessed the risk of bias and applicability concerns using the QUADAS-2 domain list. We extracted data with an effort to complete a 2 × 2 table (true positives, true negatives, false positives, and false negatives) for each of the different categories of carotid stenosis and reference standards. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where meta-analysis was possible, we used a bivariate meta-analysis model. MAIN RESULTS: We identified 25,087 unique studies, of which 22 were deemed eligible for inclusion (4957 carotid arteries). The risk of bias varied considerably across the studies, and studies were generally of moderate to low quality. We narratively described the results without meta-analysis in seven studies in which the criteria used to determine stenosis were too different from the duplex velocity criteria proposed in our protocol or studies that provided insufficient data to complete a 2 × 2 table for at least in one category of stenosis. Nine studies (2770 carotid arteries) presented DUS versus DSA results for 70% to 99% carotid artery stenosis, and two (685 carotid arteries) presented results from DUS versus CTA in this category. Seven studies presented results for occlusion with DSA as the reference standard and three with CTA as the reference standard. Five studies compared DUS versus DSA for 50% to 99% carotid artery stenosis. Only one study presented results from 50% to 69% carotid artery stenosis. For DUS versus DSA, for < 50% carotid artery stenosis, the summary sensitivity was 0.63 (95% confidence interval [CI] 0.48 to 0.76) and the summary specificity was 0.99 (95% CI 0.96 to 0.99); for the 50% to 69% range, only one study was included and meta-analysis not performed; for the 50% to 99% range, the summary sensitivity was 0.97 (95% CI 0.95 to 0.98) and the summary specificity was 0.70 (95% CI 0.67 to 0.73); for the 70% to 99% range, the summary sensitivity was 0.85 (95% CI 0.77 to 0.91) and the summary specificity was 0.98 (95% CI 0.74 to 0.90); for occlusion, the summary sensitivity was 0.91 (95% CI 0.81 to 0.97) and the summary specificity was 0.95 (95% CI 0.76 to 0.99). For sensitivity analyses, excluding studies in which participants were selected based on the presence of occlusion on DUS had an impact on specificity: 0.98 (95% CI 0.97 to 0.99). For DUS versus CTA, we found two studies in the range of 70% to 99%; the sensitivity varied from 0.57 to 0.94 and the specificity varied from 0.87 to 0.98. For occlusion, the summary sensitivity was 0.95 (95% CI 0.80 to 0.99) and the summary specificity was 0.91 (95% CI 0.09 to 0.99). For DUS versus MRA, there was one study with results for 50% to 99% carotid artery stenosis, with a sensitivity of 0.88 (95% CI 0.70 to 0.98) and specificity of 0.60 (95% CI 0.15 to 0.95); in the 70% to 99% range, two studies were included, with sensitivity that varied from 0.54 to 0.99 and specificity that varied from 0.78 to 0.89. We could perform only a few of the proposed sensitivity analyses because of the small number of studies included. AUTHORS' CONCLUSIONS: This review provides evidence that the diagnostic accuracy of DUS is high, especially at discriminating between the presence or absence of significant carotid artery stenosis (< 50% or 50% to 99%). This evidence, plus its less invasive nature, supports the early use of DUS for the detection of carotid artery stenosis. The accuracy for 70% to 99% carotid artery stenosis and occlusion is high. Clinicians should exercise caution when using DUS as the single preoperative diagnostic method, and the limitations should be considered. There was little evidence of the accuracy of DUS when compared with CTA or MRA. The results of this review should be interpreted with caution because they are based on studies of low methodological quality, mainly due to the patient selection method. Methodological problems in participant inclusion criteria from the studies discussed above apparently influenced an overestimated estimate of prevalence values. Most of the studies included failed to precisely describe inclusion criteria and previous testing. Future diagnostic accuracy studies should include direct comparisons of the various modalities of diagnostic tests (mainly DUS, CTA, and MRA) for carotid artery stenosis since DSA is no longer considered to be the best method for diagnosing carotid stenosis and less invasive tests are now used as reference standards in clinical practice. Also, for future studies, the participant inclusion criteria require careful attention.

Serum biomarkers of iron stores are associated with worse physical health-related quality of life in nondialysis-dependent chronic kidney disease patients with or without anemia.

BACKGROUND: Iron deficiency (ID) is a common condition in nondialysis-dependent chronic kidney disease (NDD-CKD) patients that is associated with poorer clinical outcomes. However, the effect of ID on health-related quality of life (HRQoL) in this population is unknown. We analyzed data from a multinational cohort of NDD-CKD Stages 3-5 patients to test the association between transferrin saturation (TSAT) index and ferritin with HRQoL. METHODS: Patients from Brazil (n = 205), France (n = 2015) and the USA (n = 293) in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps, 2013-2019) were included. We evaluated the association of TSAT and ferritin (and functional and absolute ID, defined as TSAT ≤20% and ferritin ≥300 or <50 ng/mL) on pre-specified HRQoL measures, including the 36-item Kidney Disease Quality of Life physical component summary (PCS) and mental component summary (MCS) as the primary outcomes. Models were adjusted for confounders including hemoglobin (Hb). RESULTS: TSAT ≤15% and ferritin <50 ng/mL and ≥300 ng/mL were associated with worse PCS scores, but not with MCS. Patients with composite TSAT ≤20% and ferritin <50 or ≥300 ng/mL had lower functional status and worse PCS scores than those with a TSAT of 20-30% and ferritin 50-299 ng/mL. Patients with a lower TSAT were less likely to perform intense physical activity. Adjustment for Hb only slightly attenuated the observed effects. CONCLUSIONS: Low TSAT levels, as well as both low TSAT with low ferritin and low TSAT with high ferritin, are associated with worse physical HRQoL in NDD-CKD patients, even after accounting for Hb level. Interventional studies of iron therapy on HRQoL among NDD-CKD individuals are needed to confirm these findings.

The impact of food addiction behaviours on the treatment of overweight students.

The present study evaluated the association of food addiction (FA), the change of the BMI/age z-score and the consumption of ultra-processed foods in overweight students undergoing a 16-month, multicomponent intervention in the school environment. FA was investigated using the Yale Food Addiction Scale for Children, and the dietary assessment was estimated using the semi-quantitative FFQ in overweight 9-11-year-old students (BMI/age z-score ≥ 1) of both sexes at their baseline and after the intervention (n 120). Among the schoolchildren, 33·4 % had FA in at least one of the two assessments. The analysis of mixed-effects models to assess the effect of the intervention and the change of the BMI/age z-score between evaluations showed that the occurrence of FA influenced the maintenance of weight (time#FA, ß = 0·30, 95 % CI 0·05, 0·54, P = 0·016). Weight loss was observed only in individuals who did not present FA (BMI/age z-score = -0·3). When evaluating the effect of the intervention and the dietary variables, we verified a reduction in the consumption of sugary milk-based drinks -71·13 kJ (-17 kcal), P = 0·04 only in non-FA students at the end of the study. FA has been identified as an underlying factor with therapeutic relevance, and an enhanced understanding of FA can open new paths for the prevention and management of obesity.

Access to treatment for chronic kidney disease by children and adolescents in Brazil.

BACKGROUND: This study aimed to identify main factors associated with child and adolescent access to chronic kidney disease (CKD) treatment in Brazil. METHODS: Multi-center cross-sectional study conducted in eight pediatric nephrology centers across all Brazilian geographic regions. Information was collected on characteristics associated with referral and treatment of patients with CKD. The following outcomes were analyzed as follows: (1) age at first consultation, and (2) time elapsed between referral and treatment at the specialized service. RESULTS: Three hundred thirty-five children were assessed. Variables associated with age at first consultation were as follows: CAKUT (HR=1.7; 95%CI 1.3-2.2, p<0.01); private health plan (HR=1.54; 95%CI 1.06-2.23, p=0.02); modified Medical Outcomes Study Social Support Survey mMOS-SS score (HR=1.02; 95%CI 1.00-1.03, p=0.024); maternal age (HR=0.96; 95%CI 0.95-0.97, p<0.01); and number of siblings in the household (HR=0.86; 95%CI 0.79-0.83, p<0.01). Significant variables associated with time elapsed between referral and treatment at the specialized service were as follows: each additional occupant sharing the household (HR=0.94; 95%CI:0.89-0.99, p=0.02), residing in the Northeast (HR=0.81; 95%CI:0.67-0.98, p=0.03) and having someone to take them to the physician (HR=1.36; 95%CI 1.07-1.74, p=0.01). The median time interval between patient referral and treatment by the service was 11 days (IQR 10-31). CONCLUSION: There are potentially modifiable factors hampering access of children with CKD to specialized treatment. The importance of the role of social support for the two outcomes should serve as an alert for health managers and professionals to consider this aspect throughout all steps of the care process of children with CKD.

Exploring the consumption of ultra-processed foods and its association with food addiction in overweight children.

The present study explored the consumption of ultra-processed foods and its association with food addiction in overweight children. The prevalence of food addiction was investigated using the Yale Food Addiction Scale for Children in overweight 9-11 year-old children (BMI/age ≥1 Z score) of both sexes from two schools (n = 139). Food intake was estimated by a food frequency questionnaire and the food items were classified into 4 categories: minimally processed, culinary ingredients, processed foods and ultra-processed foods (UPF), based on their degree of processing. Among the children, 95% showed at least one of the seven symptoms of food addiction and 24% presented with a diagnosis of food addiction. In analysis of covariance adjusted for age and sex, a tendency of higher consumption of added sugar (refined sugar, honey, corn syrup) and UPF was found among those diagnosed with food addiction. Multiple logistic regression adjusted for sugar, sodium and fat ingestion showed that consumption of cookies/biscuits (OR = 4.19, p = 0.015) and sausages (OR = 11.77, p = 0.029) were independently associated with food addiction. The identification of foods that may be associated with addictive behavior is very important for correctly treating and preventing childhood obesity, which continues to be one of the greatest health problems in the world.

Prevalence of chronic kidney disease and comorbidities in isolated African descent communities (PREVRENAL): methodological design of a cohort study.

BACKGROUND: Chronic kidney disease (CKD) is considered a serious public health problem, both in Brazil and worldwide, with an increasing number of cases observed inrecent years. Especially, CKD has been reported to be highly prevalent in those of African descent. However, Brazil lacks data from early-stage CKD population studies, and the prevalence of CKD is unknown for both the overall and African descent populations. Hence, the present study aimsto estimate the prevalence of early-stage CKD and its associated risk factors in African-Brazilians from isolated African-descent communities. Herein, the detailed methodology design of the study is described. METHODS: This population-based, prospective, longitudinal, cohort study (PREVRENAL) is performed in three stages: first, clinical, nutritional, and anthropometric evaluations; measurements of serum and urinary markers; and examinations of comorbiditieswere performed. Second, repeated examinations of individuals with CKD, systemic arterial hypertension, and/or diabetes mellitus; image screening; and cardiac risk assessment were performed. Third, long-term monitoring of all selected individuals will be conducted (ongoing). Using probability sampling, 1539 individuals from 32 communities were selected. CKD was defined asaglomerular filtration rate (GFR) ≤60 mL/min/1.73m2 and albuminuria > 30 mg/day. DISCUSSION: This study proposes to identify and monitor individuals with and without reduced GFR and high albuminuria in isolated populations of African descendants in Brazil. As there are currently no specific recommendations for detecting CKD in African descendants, four equations for estimating the GFR based on serum creatinine and cystatin C were used and will be retrospectively compared. The present report describes the characteristics of the target population, selection of individuals, and detection of a population at risk, along with the imaging, clinical, and laboratory methodologies used. The first and second stages have been concluded and the results will be published in the near future. The subsequent (third) stage is the long-term, continuous monitoring of individuals diagnosed with renal abnormalities or with CKD risk factors. The entire study population will be re-evaluated five years after the study initiation. The expectation is to obtain information about CKD evolution among this population, including the progression rate, complication development, and cardiovascular events.

Albuminuria, renal function and blood pressure in undernourished children and recovered from undernutrition.

BACKGROUND: The objective of this study was to investigate some biomarkers of renal function and blood pressure in children who had recovered from undernutrition. METHODS: This was cross-sectional, comparative study in which a convenience sample of children of both genders (n = 126; age range 6-16 years) treated at the Centre for Nutritional Recovery and Education (São Paulo, Brazil) was used. These children were classified into four groups for analysis: (1) children who were well nourished (control group; n = 50), (2) those showing stunted growth (stunted group; n = 22), (3) those who were underweight (underweight group; n = 23) and (4) those who had recovered from undernutrition (recovered group; n = 31). RESULTS: No between-group differences were found for mean levels of albuminuria, serum creatinine and cystatin C, and similar mean estimates of glomerular filtration rate (eGFR; using either creatinine, cystatin C or both). Almost 14% of the stunted group, 4% of the underweight group and 3% of the recovered group had albuminuria of >30 mg/g creatinine (chi-square p = 0.034); none of the control children showed albuminuria of >30 mg/g creatinine. Mean systolic (SBP) and diastolic blood pressure (DBP) adjusted for age and gender of the children in the stunted [SBP (95% confidence interval): 92 (88-96) mmHg; DBP: 47 (44-49) mmHg] and recovered [SBP: 93 (90-96) mmHg; DBP: 49 (47-51) mmHg] groups were significantly lower than those of the controls [SBP: 98 (95-100) mmHg, P = 0.027; DBP: 53 (52-55) mmHg, P = 0.001]. After additional adjustment for height, mean DBP remained significantly lower in the recovered group compared with the control group [49 (46-51) vs. 53 (51-55) mmHg, respectively; P = 0.018). Logistic regression analysis showed that the stunted group had a 8.4-fold higher chance of developing albuminuria (>10 mg/g creatinine) than the control children (P = 0.006). CONCLUSIONS: No alterations in renal function were found in underweight children and those who had recovered from undernutrition, whereas children with stunted growth presented with a greater risk for albuminuria. A lower DBP was found in children with stunted growth and those who had recovered from undernutrition.

Effectiveness of a 16-month multi-component and environmental school-based intervention for recovery of poor income overweight/obese children and adolescents: study protocol of the health multipliers program.

BACKGROUND: Excess of weight is a serious public health concern in almost all countries, afflicting people of different ages and socioeconomic backgrounds. Studies have indicated the need for developing treatment strategies that intervene directly in the obesogenic environment. This study aims to evaluate the effectiveness of a multi-component and environmental school-based intervention, lasting 16 months, on the recovery of the nutritional status of low-income children and adolescents with overweight/ obesity. METHODS/STUDY DESIGN: The study was conducted by the Center for Recovery and Nutritional Education (CREN) in São Paulo, Brazil. Two schools located in poor neighborhoods were selected for the intervention, between March 2016 and June 2017. The participants were all students aged 8 to 12 years from the two participating schools. At the beginning of the intervention, anthropometric measurements were carried out to assess the nutritional status of the students. For convenience, students from one of the schools were considered as the control group, while those from the other school formed the experimental group. The intervention in the experimental group (n = 438) consists of the following weekly activities at school: psychological counseling in groups, theoretical/practical nutrition workshops, and supervised physical education classes. In addition, theoretical and practical educational activities are held regularly for parents, teachers, and cooks. Students with excess of weight (≥1 body mass index [BMI] -for-age Z score, n = 138) received clinical and nutritional care periodically at the outpatient care at CREN. Students enrolled in the control group (n = 353) participated in psychological counseling groups and theoretical/practical nutrition workshops for 6 months held in the school environment to provide motivation to entire classrooms. In the following 10 months, students with excess of weight from the control group (n = 125) were invited to attend the routine outpatient care at CREN. DISCUSSION: This study is the first to assess the effectiveness of a multi-component and environmental school-based intervention for the recovery of low-income, overweight/obese children and adolescents. If positive, the results demonstrate the feasibility for the recovery of excess of weight in populations of similar conditions and age. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials - ReBEC Primary Id Number RBR-9t2jr8 . Registration Date: Nov. 30, 2016. Retrospectively registered. Protocol version: 3.

Inequality in pediatric kidney transplantation in Brazil.

BACKGROUND: The aim of this study was to describe the access and factors associated with kidney transplantation for children in different regions of Brazil. METHODS: We analyzed a cohort of 1211 children enrolled on the transplant list from January 2011 to December of 2013. We fitted regression models to investigate factors associated with: (a) undergoing kidney transplantation from a deceased donor, and (b) being removed from the waiting list. RESULTS: The incidence of transplantation was uneven across regions, with the lowest rate at 0.4 per million age-related population (pmarp) in the Midwest and the highest incidence rate of 8.3 cases pmarp in the South. Children from the North and the Midwest regions had a 3-4 times lower probability of undergoing a deceased donor transplant (p < 0.05). Apart from the geographic region, age of recipients and GDP influenced the outcome. The likelihood of undergoing transplantation was very low in the youngest children in the North and Midwest. The number of transplant centers was not associated with either outcome. CONCLUSIONS: Factors of inequality in transplantation in Brazil are of macroeconomic origin, but there is room to reduce inequalities. Training existing transplant center professionals in the care of children could diminish the discrepancies.

Prophylactic treatment of chronic renal disease in patients undergoing peritoneal dialysis and colonized by Staphylococcus aureus: a systematic review and meta-analysis.

BACKGROUND: This study was performed to evaluate the clinical effectiveness of alternative strategies for the prevention and treatment of patients with chronic kidney disease undergoing peritoneal dialysis and colonized by Staphylococcus aureus. METHODS: A systematic review and meta-analysis were performed. The literature search involved the following databases: the Cochrane Controlled Trials Register, Embase, LILACS, CINAHL, SciELO, and PubMed/Medline. The descriptors were "Staphylococcus aureus," "MRSA," "MSSA," "treatment," "decolonization," "nasal carrier," "colonization," "chronic kidney disease," "dialysis," and "peritoneal dialysis." Randomized controlled trials that exhibited agreement among reviewers as shown by a kappa value of >0.80 were included in the study; methodological quality was evaluated using the STROBE statement. Patients who received various antibiotic treatments (antibiotic group) or topical mupirocin (mupirocin group) were compared with those who received either no treatment or placebo (control group). Patients in the antibiotic group were also compared with those in the mupirocin group. RESULTS: In total, nine studies involving 839 patients were included in the analysis, 187 (22.3 %) of whom were nasal carriers of S. aureus. The probability of S. aureus infection at the catheter site for peritoneal dialysis was 74 % lower in the mupirocin than control group (odds ratio [OR], 0.26; 95 % confidence interval [CI], 0.14-0.46; p < 0.001), 56 % lower in the antibiotic than control group (OR, 0.44; 95 % CI, 0.19-0.99; p = 0.048), and 52 % lower in the mupirocin than antibiotic group (OR, 0.48; 95 % CI, 0.21-1.10; p = 0.084). The difference in the probability of S. aureus peritonitis in patients undergoing peritoneal dialysis was not statistically significant among the three groups. CONCLUSIONS: Mupirocin and topical antibiotics were effective for reduction of S. aureus catheter site infection in patients undergoing peritoneal dialysis when compared with no treatment or placebo. However, evidence was insufficient to identify the optimal agent, route, or duration of antibiotics to treat peritonitis.

Risk factors for bloodstream infection in patients at a Brazilian hemodialysis center: a case-control study.

BACKGROUND: Infection is the leading cause of morbidity and the second leading cause of mortality in patients on renal replacement therapy. The rates of bloodstream infection in hemodialysis patients vary according to the type of venous access used. Gram-positive bacteria are most frequently isolated in blood cultures of hemodialysis patients. This study evaluated risk factors for the development of bloodstream infections in patients undergoing hemodialysis. METHODS: Risk factors associated with bloodstream infections in patients on hemodialysis were investigated using a case-control study conducted between January 2010 and June 2013. Chronic renal disease patients on hemodialysis who presented with positive blood cultures during the study were considered as cases. Controls were hemodialysis patients from the same institution who did not present with positive blood cultures during the study period. Data were collected from medical records. Logistic regression was used for statistical analysis. RESULTS: There were 162 patients included in the study (81 cases and 81 controls). Gram-positive bacteria were isolated with the highest frequency (72%). In initial logistic regression analysis, variables were hypertension, peritoneal dialysis with previous treatment, type and time of current venous access, type of previous venous access, previous use of antimicrobials, and previous hospitalization related to bloodstream infections. Multiple regression analysis showed that the patients who had a central venous catheter had an 11.2-fold (CI 95%: 5.17-24.29) increased chance of developing bloodstream infections compared with patients who had an arteriovenous fistula for vascular access. Previous hospitalization increased the chance of developing bloodstream infections 6.6-fold (CI 95%: 1.9-23.09). CONCLUSIONS: Infection prevention measures for bloodstream infections related to central venous catheter use should be intensified, as well as judicious use of this route for vascular access for hemodialysis. Reducing exposure to the hospital environment through admission could contribute to a reduction in bloodstream infections in this population.

Screening and treatment for Staphylococcus aureus in patients undergoing hemodialysis: a systematic review and meta-analysis.

BACKGROUND: This study was performed to evaluate the effectiveness of surveillance for screening and treatment of patients with chronic kidney disease undergoing hemodialysis and colonized by Staphylococcus aureus. METHODS: A systematic review and meta-analysis were performed. The literature search involved the following databases: the Cochrane Controlled Trials Register, Embase, LILACS, CINAHL, SciELO, and PubMed/Medline. The descriptors were "Staphylococcus aureus", "MRSA", "MSSA", "treatment", "decolonization", "nasal carrier", "colonization", "chronic kidney disease", "dialysis", and "haemodialysis" or "hemodialysis". Five randomized controlled trials that exhibited agreement among reviewers as shown by a kappa value of >0.80 were included in the study; methodological quality was evaluated using the STROBE statement. Patients who received various treatments (various treatments group) or topical mupirocin (mupirocin group) were compared with those who received either no treatment or placebo (control group). The outcomes were skin infection at the central venous catheter insertion site and bacteremia. RESULTS: In total, 2374 patients were included in the analysis, 626 (26.4%) of whom were nasal carriers of S. aureus. The probability of S. aureus infection at the catheter site for hemodialysis was 87% lower in the mupirocin group than in the control group (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.05-0.34; p<0.001). The risk of bacteremia was 82% lower in the mupirocin group than in the control group (OR, 0.18; 95% CI, 0.08-0.42; p<0.001). No statistically significant difference in bacteremia was observed between the various treatments group (excluding mupirocin) and the control group (OR, 0.77; 95% CI, 0.51-1.15; p=0.20). CONCLUSIONS: Twenty-six percent of patients undergoing hemodialysis were nasal carriers of S. aureus. Of all treatments evaluated, topical mupirocin was the most effective therapy for the reduction of S. aureus catheter site infection and bacteremia in patients undergoing chronic hemodialysis.

Sex-specific differences in a large cohort of Brazilian incident dialysis patients over 12 years: A retrospective study.

OBJECTIVE: Sex-specific differences in the epidemiology of chronic kidney disease, such as higher prevalence of women on pre-dialysis and men on chronic dialysis treatment, have been reported worldwide. In this regard, data from non-high-income countries are scarce. We aimed to compare the demographic, clinical, and dialysis characteristics of incident dialysis patients, both men and women, in a large cohort of Brazilian patients over a 12-year period. METHODS: This was a multicentric retrospective cohort study coordinated by the Brazilian Society of Nephrology. The study included all adult incident dialysis patients in the Brazilian Dialysis Registry from January 2011 to December 2022. The variables studied encompassed age, skin color, education, CKD etiology, predialysis nephrologist care, dialysis characteristics, and geographic region. Additionally, the sample was analyzed for each of the three 4-year periods over the 12 years of data collection. RESULTS: A total of 24,632 incident dialysis patients were included. Men were 59.1% of the dialysis population, remaining stable over the three 4-year periods. Besides other differences, women started dialysis younger (58.5 ± 16.2 years vs 59.5 ± 14.4 years; p < 0.001), had a lower educational level (less than 8 years at school: 54% vs 44%; p < 0.001), received more predialysis nephrologist care (46.2% vs 44.2%; p = 0.04), and had a higher prevalence of peritoneal dialysis (4.4% vs 3.5%; p = 0.03). CONCLUSION: We consistently observed a higher prevalence of men on dialysis and differences in demographic, clinical, and dialysis characteristics. The underlying reasons for these sex differences still necessitate further clarification.

Brazilian Dialysis Survey 2022.

INTRODUCTION: The Brazilian Dialysis Survey (BDS) is an annual national survey about patients on chronic dialysis that contributes to health policies. OBJECTIVE: To report the 2022 epidemiological data from the BDS of the Brazilian Society of Nephrology (BSN). METHODS: A survey was carried out in Brazilian chronic dialysis centers using an online questionnaire that included clinical and epidemiological aspects of patients on chronic dialysis, dialysis therapy data, and dialysis center characteristics. RESULTS: Overall, 28% (n = 243) of the centers answered the questionnaire. In July 2022, the estimated total number of patients on dialysis was 153,831. The estimated prevalence and incidence rates of patients per million population (pmp) were 758 and 214, respectively. Of the prevalent patients, 95.3% were on hemodialysis (HD, 4.6% of these on hemodiafiltration) and 4.7% on peritoneal dialysis (PD). Only 1.3% of patients were not vaccinated against COVID-19. The prevalence of anemia (Hb < 10g/dL) was 27% and hyperphosphatemia (P > 5.5mg/dL) reached 30%. The estimated overall crude annual mortality rate was 17.1%. CONCLUSIONS: The absolute number and prevalence rate of patients on chronic dialysis continue to increase. A growing number of patients were receiving hemodiafiltration. The mortality rate decreased, probably due to the end of COVID-19 pandemic. The conclusions were drawn in the context of relatively low voluntary participation, which imposed methodological limitations on our estimates.

Comparison of 1-year survival between patients initiating chronic hemodialysis under public and private health insurance: register-based data analysis from Brazil.

PURPOSE: Brazil has one of the world's highest numbers of patients on hemodialysis (HD). Most dialysis centers are private and perform HD for patients with private and public health insurance. We compared 1-year survival between patients initiating chronic HD with public and private health insurance. METHODS: This is an HD register-based retrospective cohort. Adult patients starting HD from January 2011 to December 2021 were included. Survival analysis was stratified according to the period entered in the HD register. Multivariate Cox regression focused on 1-year survival differences between private and public patients. RESULTS: In the final sample (n = 5114), 68.5% of participants had public and 31.3% to private health insurance, with overall 1-year survival of 92.8% and 89.9%, respectively (p = 0.002). Crude analysis showed a slightly higher survival rate among patients with public health insurance than those with private health insurance (91 vs. 87%, p = 0.030) in the first period (2019-21). However, the adjusted hazard ratio (HR) did not remain significantly higher for patients with private health insurance compared to those with public health insurance (HR = 1.07; 95% CI 0.80-1.41; p = 0.651), even after propensity score matching of the groups by several baseline features. CONCLUSION: Brazilian chronic HD patients funded by either private health plans or the public system have a similar 1-year mortality risk after controlling for several sociodemographic and clinical parameters.

Estimation of glomerular filtration rate from serum creatinine and cystatin C in octogenarians and nonagenarians.

BACKGROUND: Equations to estimate GFR have not been well validated in the elderly and may misclassify persons with chronic kidney disease (CKD). We measured GFR and compared the performance of the Modification of Diet in Renal Disease (MDRD), the Chronic Kidney Disease-Epidemiology Collaboration (CKD-Epi) and the Berlin Initiative Study (BIS) equations based on creatinine and/or cystatin C in octogenarians and nonagenarians. METHODS: Using cross-sectional analysis we assessed 95 very elderly persons (mean 85 years) living in the community. GFR was measured by iohexol (mGFR) and compared with estimates using six equations: MDRD, CKD-Epi_creatinine, CKD-Epi_cystatin, CKD-Epi_creatinine-cystatin, BIS_creatinine and BIS_creatinine-cystatin. RESULTS: Mean mGFR was 55 (range,19-86) ml/min/1.73 m(2). Bias was smaller with the CKD-Epi_creatinine-cystatin and the CKD-Epi_creatinine equations (-4.0 and 1.7 ml/min/1.73 m(2)). Accuracy (percentage of estimates within 30% of mGFR) was greater with the CKD-Epi_creatinine-cystatin, BIS_creatinine-cystatin and BIS_creatinine equations (85%, 83% and 80%, respectively). Among the creatinine-based equations, the BIS_creatinine had the greatest accuracy at mGFR < 60 ml/min/1.73 m(2) and the CKD-Epi_creatinine was superior at higher GFRs (79% and 90%, respectively). The CKD-Epi_creatinine-cystatin, BIS_creatinine-cystatin and CKD-Epi_cystatin equations yielded the greatest areas under the receiver operating characteristic curve at GFR threshold = 60 ml/min/1.73 m 2 (0.88, 0.88 and 0.87, respectively). In participants classified based on the BIS_creatinine, CKD-Epi_cystatin, or BIS_creatinine-cystatin equations, the CKD-Epi_creatinine-cystatin equation tended to improve CKD classification (net reclassification index: 12.7%, p = 0.18; 6.7%, p = 0.38; and 15.9%; p = 0.08, respectively). CONCLUSIONS: GFR-estimating equations CKD-Epi_creatinine-cystatin and BIS_creatinine-cystatin showed better accuracy than other equations using creatinine or cystatin C alone in very elderly persons. The CKD-Epi_creatinine-cystatin equation appears to be advantageous in CKD classification. If cystatin C is not available, both the BIS_cr equation and the CKD-Epi_cr equation could be used, although at mGFR < 60 ml/min/1.73 m(2), the BIS_cr equation seems to be the best alternative.