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Pietro Ravani

Publications and source records attributed to Pietro Ravani.

14 recordsLinked to original sources
PubMed2026

Methods for defining equity-stratifying variables: a systematic review of validation studies.

BACKGROUND AND OBJECTIVE: Disease burden is often disproportionally higher among those who are socially disadvantaged by factors defined in the PROGRESS-Plus framework (ie, Place of residence, Race/ethnicity/culture/language, Occupation, Gender/sex, Religion, Education, Socioeconomic status, and Social capital, with "Plus" covering features like age and disability). The accuracy and applicability of case definitions to identify these variables from administrative and clinical health data are unknown. We conducted a systematic review to explore how equity-stratifying variables, as categorized by the PROGRESS-Plus framework, have been defined and validated in epidemiologic studies using administrative health, population-level, or electronic health record (EHR) data. METHODS: Medline, EMBASE, CINAHL, Web of Science, and Google Scholar were searched from the inception of the databases to 2024 for validation studies of equity-stratifying variables in adults using administrative health datasets, health registries, or EHR data. Titles and abstracts, followed by relevant full-text articles, were screened in duplicate by two reviewers for eligibility. The data sources utilized, algorithms employed, and their associated performance measures were extracted and synthesized from included studies. Given substantial heterogeneity in study design, equity-stratifying variable definition, and performance metrics, meta-analysis was not possible. RESULTS: Of the 9099 unique citations screened, 188 full texts were reviewed and 116 were included in this review. Most studies were published between 2019 and 2024 (n = 64, 55%) and were validation studies of race/ethnicity definitions that used race/ethnicity codes or surname list algorithms (n = 66, 57%). No studies examined religion. Regarding the reported performance measure estimates, the race/ethnicity/culture/language equity-stratifying variables category had the largest variability across sensitivity, positive predictive value (PPV), and Cohen's Kappa. Occupation validation studies had the lowest variation in sensitivity and PPV. CONCLUSION: Despite an increasing number of publications reporting on the validation of equity-stratifying variables relevant to the PROGRESS-Plus framework, performance measures varied widely across studies. The significant heterogeneity in equity-stratifying variable definitions and methods used to validate them support the need for further rigorous validation of equity-stratifying variables in administrative and clinical health data. PLAIN LANGUAGE SUMMARY: Disease burden is often higher in people who experience financial hardships, lower level of education, discrimination due to race/ethnicity, and unstable housing. These social factors can be considered health equity factors and are important for understanding health inequalities. Health researchers often use large datasets, such as hospital or electronic health records (EHRs), to study these health equity factors. However, it is not clear how accurately these data sources capture information about people's social circumstances and how these factors are defined. In this study, we reviewed existing research to understand how health equity factors have been defined across health data sources and how accurate they are at measuring aspects of health equity and social disadvantage. Of the more than 9000 studies we identified, we included 116 that met our criteria for this systematic review. Most included studies focused on identifying race and ethnicity, often using codes or surname-based methods. We found that the accuracy of these methods varied widely across studies, meaning results may not always be reliable or comparable. Overall, our findings show that there are inconsistencies in how social factors are defined and measured in health data. This makes it difficult to fully understand and address health inequalities using routinely collected health data. More work is needed to develop and validate better quality and more consistent methods for capturing these important social factors.

Humans↗
PubMed2006

IgA nephropathy: the presence of familial disease does not confer an increased risk for progression.

BACKGROUND: Immunoglobulin A (IgA) nephropathy is the most common form of glomerulonephritis worldwide. Familial and sporadic cases are recognized, and a locus associated with the familial form of the disease was mapped to chromosome 6. Recent data suggest the familial IgA nephropathy form may have a poorer outcome than the sporadic form. METHODS: We tested the hypothesis of unequal survival rates between the 2 forms of disease by analyzing time from biopsy to end-stage renal disease in patients of Italian ancestry; 589 patients with sporadic and 96 patients with familial IgA nephropathy. RESULTS: Overall 10- and 20-year renal survival probabilities of the cohort as a whole were 71% and 50%, respectively. Macroscopic hematuria was the modality of clinical presentation in 51% of patients with familial IgA nephropathy and 39% of patients with sporadic IgA nephropathy. At univariable analysis, the sporadic form of IgA nephropathy was associated significantly with increased risk for renal death. However, patients with the sporadic form tended to be more hypertensive and diagnosed later, with signs of more advanced renal disease than those with familial disease at baseline. In the regression model, form of disease lost any independent effect. Only male sex, lower baseline glomerular filtration rate, greater proteinuria, and histopathologic score proved to be independent predictors of disease progression. Treatment with steroids or angiotensin-converting enzyme inhibitors was associated with improved outcomes. CONCLUSION: Our study does not confirm that familial IgA nephropathy has a worse prognosis than the sporadic form. The similar renal phenotype may support a common pathogenic mechanism underlying familial and sporadic IgA nephropathy.

Adult↗
PubMed2005

Asymmetrical dimethylarginine predicts progression to dialysis and death in patients with chronic kidney disease: a competing risks modeling approach.

High plasma asymmetrical dimethylarginine (ADMA) signals endothelial dysfunction and atherosclerosis in the general population and predicts mortality in ESRD. The relationship among plasma levels of ADMA, renal function, and the risk for progression to ESRD (halving GFR or dialysis start) and death in an incident cohort of 131 patients with chronic kidney disease was investigated. Cox's competing risk regression was used to model double-failure times (progression to ESRD and death) as a function of ADMA. Covariates that were considered for adjustment included clinical characteristics, baseline GFR (Modification of Diet in Renal Disease equation 7 formula), proteinuria, traditional cardiovascular risk factors, serum C-reactive protein, homocysteine, and concomitant therapies. Mean age at enrollment was 71 +/- 11 yr, and 24% of patients had diabetes. Baseline GFR ranged from 8 to 77 ml/min per 1.73 m2 (average 31 +/- 15 ml/min per 1.73 m2). ADMA was inversely related to GFR, ranking as the third predicting factor (partial r = -0.22, P = 0.01), after hemoglobin and urinary protein, in a general linear model that included multiple correlates of GFR. After a mean follow-up of 27 mo (range 3.4 to 36), 29 patients progressed to ESRD and 31 died. ADMA (hazard ratio per 0.1 muM/L 1.203; 95% confidence interval 1.071 to 1.350) predicted event occurrence independent of other potential confounders, including GFR, proteinuria, hemoglobin, and homocysteine. In patients with mild to advanced chronic kidney disease, plasma ADMA is inversely related to GFR and represents a strong and independent risk marker for progression to ESRD and mortality. These novel findings further expand the implications of previous observations in ESRD patients and generate hypotheses on the role of ADMA in progressive chronic nephropathies.

Aged↗
PubMed2004

The short- and long-term impact of multi-disciplinary clinics in addition to standard nephrology care on patient outcomes.

BACKGROUND: This two country case control study of incident dialysis patients evaluates the outcomes of patients exposed to formalized multi-disciplinary clinic (MDC) programmes vs standard nephrologist care. METHODS: Patients commencing dialysis in two centres (Vancouver, Canada and Cremona, Italy) were evaluated at and after dialysis start, as a function of MDC exposure vs nephrologist care alone. Only chronic kidney disease patients, with longer than 3 months of exposure to nephrology care, who had not previously received kidney replacement therapy were included. Study outcomes included laboratory parameters and survival. The MDC was similar in both countries and average exposure was 6-8 h per patient-year, as compared to 2-4 h for standard care. All patients had equal access to resources prior to dialysis and with respect to dialysis start, as all had been referred to the same local nephrology practices. RESULTS: During the evaluation period 288 patients commenced dialysis after receiving more than 3 months nephrology care prior to dialysis. There were no major demographic differences between the cohorts. Mean duration of nephrology care prior to dialysis was 42 months, and dialysis was initiated at similar low glomerular filtration rate (GFR), though statistically significantly different (7.0 and 8.4 ml/min/m2, P = 0.001). The MDC patients had higher haemoglobin (102 vs 90 g/l, P<0.0001), albumin (37.0 vs 34.8 g/l, P = 0.002) and calcium levels (2.29 vs 2.16 mmol/l, P<0.0001) at dialysis start. Survival was significantly better in the MDC group demonstrated by Kaplan-Meier analysis (P = 0.01). Cox proportional hazards analysis demonstrated standard nephrology clinic vs MDC attendance was a statistically significant independent predictor of death (hazards ratio = 2.17, 95% confidence interval 1.11-4.28) after adjusting for other variables known to impact outcomes. CONCLUSIONS: This analysis of outcomes in two different countries suggests that despite equal and long exposure to nephrology care prior to dialysis, there appears to be an association of survival advantage for those patients exposed to formalized clinic care in addition to standard nephrologist follow-up. While other known predictors of survival such as adequacy of dialysis and severity of illness measures were not included in the model, those parameters require time on dialysis to be accumulated. Thus, the data do suggest that knowledge of patient status at the time of dialysis start is important. Further research is needed to determine which specific components of care both prior to dialysis and after its commencement are most important with respect to outcomes.

Adult↗
PubMed2004

Cardiovascular comorbidity and late referral impact arteriovenous fistula survival: a prospective multicenter study.

Autologous arteriovenous fistulas (AVF) have the best 5-yr patency and the lowest complication rate among hemodialysis vascular accesses. However, maturation requirements to optimize survival are unknown. A longitudinal cohort study was conducted to ascertain risk factors for failure, maturation time, and survival of the first AVF. All patients who initiated hemodialysis between January 1, 1997, and December 31, 2002, in three centers were included in this study. Analysis was restricted to patients who received an AVF. Cox regression was used to estimate the association between predictors of interest and primary and secondary AVF survival. Of the 535 patients enrolled (mean age, 66.5 yr; 57.8% male; 26.7% diabetic), 513 (96%) received an AVF. Patients who initiated with catheters (47%) cannulated their AVF earlier (median maturation period, 0.78 versus 1.80 mo; P < 0.001). Median primary and secondary survivals were longer than 50 and 72 mo, respectively. After adjustment for confounding factors, cardiovascular disease (hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.26 to 2.67), utilization earlier than 1 mo after placement (HR, 1.94; 95% CI, 1.34 to 2.82), and referral within 3 mo of dialysis start (HR, 1.55; 95% CI, 1.04 to 2.32) were associated with a reduction in primary AVF survival. Presence of cardiovascular disease (HR, 2.21; 95% CI, 1.38 to 3.55), maturation time <15 d (HR, 2.12; 95% CI, 1.20 to 3.73), and presence of catheters at hemodialysis initiation (HR, 1.79; 95% CI, 1.13 to 2.84) were associated with lower secondary AVF survival. It is concluded that cardiovascular disease, late referral, temporary catheters, and early cannulation are associated with impaired AVF survival. It is recommended that AVF be allowed to mature at least 1 mo before cannulation.

Aged↗
PubMed2003

The choice of the dialysate calcium concentration in the management of patients on haemodialysis and haemodiafiltration.

The choice of an appropriate dialysate calcium (Ca) concentration is crucial in the management of dialysis patients: an excessive Ca load has been associated with vascular calcifications, whereas Ca depletion can worsen secondary hyperparathyroidism (HPT) and decrease bone mass. In haemodialysis (HD), Ca transfer by diffusion depends on the concentration gradient between dialysate and blood, and a gain of Ca is expected when the dialysate Ca is >1.5 mmol/l. However, Ca losses by convective transport (ultrafiltration rate) can even exceed the amount of Ca gained by diffusion. Dialysis Ca balances, in normocalcaemic patients with a mean weight loss of 2-4 kg per session, have been shown to be positive, moderately negative or clearly negative using a dialysate Ca of 1.75, 1.50 or 1.25 mmol/l, respectively. Serum ionized Ca increases during sessions with a dialysate Ca of 1.5 and 1.75mmol/l, and decreases to the lower limits of normal after HD with 1.25 mmol/l. In haemodiafiltration (HDF), Ca mass transfer is strongly affected by the Ca content in the replacement solutions. Bicarbonate-containing bags are Ca free so that dialysate Ca needs to be increased above 1.75 mmol/l to overcome the convective losses and avoid markedly negative balances. Ca mass transfer in HDF is also affected by the infusion mode. Ca balance in post-dilution HDF, for a given concentration gradient between blood and dialysate, does not differ from HD. Conversely, in pre-dilution HDF, dialysate Ca concentration should be increased by approximately 0.25 mmol/l to maintain comparable balances. A given dialysate Ca concentration should be prescribed considering the dialysis Ca mass balance, other concomitant therapies (Ca salts, vitamin D metabolites) and the type of bone disease. The current strategy of maintaining normal Ca levels by ensuring an adequate intestinal Ca absorption with large doses of Ca-containing phosphate binders and concomitantly avoiding positive Ca balances from dialysis by using a low Ca dialysate has been questioned recently because of the risk of either worsening HPT or accelerating the progression of vascular calcifications. A dialysate Ca of 1.5 mmol/l seems to be suitable for the majority of patients on HD or post-dilution on-line HDF because the moderately negative dialysis balances can be easily counterbalanced by the administration of mild doses of Ca-containing phosphate binders in order to ensure a neutral total body Ca balance. If necessary, aluminium-free and Ca-free binders can be added to achieve a satisfactory control of hyperphosphataemia, while avoiding an excessive Ca load.

Calcium↗
PubMed2003

Predictors of renal and patient outcomes in atheroembolic renal disease: a prospective study.

Atheroembolic renal disease (AERD) is part of a multisystemic disease accompanied by high cardiovascular comorbidity and mortality. Interrelationships between traditional risk factors for atherosclerosis, vascular comorbidities, precipitating factors, and markers of clinical severity of the disease in determining outcome remain poorly understood. Patients with AERD presenting to a single center between 1996 and 2002 were followed-up with prospective collection of clinical and biochemical data. The major outcomes included end-stage renal disease (ESRD) and death. Ninety-five patients were identified (81 male). AERD was iatrogenic in 87%. Mean age was 71.4 yr. Twenty-three patients (24%) developed ESRD; 36 patients (37.9%) died. Cox regression analysis showed that significant independent predictors of ESRD were long-standing hypertension (hazard ratio [HR] = 1.1; P < 0.001) and preexisting chronic renal impairment (HR = 2.12; P = 0.02); use of statins was independently associated with decreased risk of ESRD (HR = 0.02; P = 0.003). Age (HR = 1.09; P = 0.009), diabetes (HR = 2.55; P = 0.034), and ESRD (HR = 2.21; P = 0.029) were independent risk factors for patient mortality; male gender was independently associated with decreased risk of death (HR = 0.27; P = 0.007). Cardiovascular comorbidities, precipitating factors, and clinical severity of AERD had no prognostic impact on renal and patient survival. It is concluded that AERD has a strong clinical impact on patient and renal survival. The study clearly shows the importance of preexisting chronic renal impairment in determining both renal and patient outcome, this latter being mediated by the development of ESRD. The protective effect of statins on the development of ESRD should be evaluated in a prospective study.

Aged↗
PubMed2002

Vascular access surgery managed by renal physicians: the choice of native arteriovenous fistulas for hemodialysis.

BACKGROUND: After decades of success in dialysis research and treatment, prompt availability of a well-functioning vascular access for dialysis remains a disturbing problem. On the basis of a single-center experience in which nephrologists are responsible for access surgery, we sought to identify predictors of catheter use at the start of hemodialysis (HD) therapy and risk factors affecting first permanent access survival. METHODS: Demographics, comorbid conditions, predialysis follow-up, and access-related procedures of the 197 consecutive patients beginning extracorporeal treatment between 1995 and 2001 were prospectively entered into our database. RESULTS: Despite the high prevalence of comorbidities (diabetes, 22%; cardiovascular disease, 50%; neoplasm, 15%), all subjects received a native fistula as a first permanent access, but almost 60% initiated HD therapy using a catheter. The latter showed more comorbidities and were referred later. According to the Kaplan-Meier method, median primary and secondary survivals of the first fistula were 38.1 months and more than 70 months, respectively. The Cox model indicated that diabetes and previous catheter use were independently associated with 85% and 63% greater relative risks for first failure, but only diabetes led to a greater risk for final failure (relative risk, 2.38; P = 0.05). CONCLUSION: Both the absence of predialysis care and presence of comorbidity influence access type at HD therapy initiation and fistula survival. Earlier intervention strategies can increase the use and durability of a native fistula for HD. Direct involvement of nephrologists in the management of access surgery can be helpful in this respect.

Aged↗
PubMedDate not supplied

Arteriovenous fistula surgery: an American perspective from Italy.

Hemodialysis depends on durable, long-term vascular access for the patient. In the United States, arteriovenous fistula (AVF) creation rates are lower than they are in Europe. Excess morbidity and mortality has been attributed to reliance on catheters and prosthetic grafts. In Italy, there is a high rate of fistula creation, and they are predominantly created by nephrologists. As American interventional nephrologists become more involved in the procedural aspects of renal care, consideration should be given to replicating the Italian model of dialysis access creation. Specific aspects of the surgical technique, comparison to available literature, and potential reasons for higher fistula creation rates are explored from the vantage point of an American nephrologist visiting Italy. The pertinence to American dialysis access programs is discussed, as is the opportunity for interventional nephrologists in the United States to further expand and improve upon the successes of the Italian experience.

Arteriovenous Shunt, Surgical↗
PubMedDate not supplied

Structured pre-dialysis programs: more than just timely referral?

BACKGROUND: Patients who begin chronic dialysis within 3 months of seeing a nephrologist (late referral)have increased morbidity and mortality. However, it is not known whether formal pre-dialysis education programs (PEPs) are more advantageous, regarding early dialysis outcomes and resource use, than unstructured specialist follow-up. METHODS: We prospectively collected information on specialist care, unstructured or PEP, modality choice and hospitalizations in the 1st 3 months of dialysis for all consecutive patients who started dialysis between 1st January 1999 and 30th June 2002 in two Italian centers. RESULTS: The 229 patients who participated in this study (62% male, median age 70 yrs) had a high prevalence of diabetes (27.5%) and cardiovascular disease (60%). Of these, 22.7% received unstructured follow-up and 40.6% received PEP care. Peritoneal dialysis (PD) was the first choice modality for 41.5% of patients and 55% had a planned start. Excluding late referrals (36.7%), the likelihood of PD selection was similar between PEP and unstructured care (52.7% vs. 40.4%, p = NS), while that of a planned start was greater among PEP patients (91.4% vs. 38.5%, p < 0.001). Multivariate analysis showed that only PEP (but not unstructured care) vs. late referral had a significant association with reduced odds of hemodialysis (HD) selection (OR: 0.301, [95%CI 0.153, 0.594]), emergency start (0.031 [0.013, 0.075]), 1st hospitalization > 5 days (0.165 [0.081, 0.333]), and further hospitalizations (0.346 [0.174, 0.685]). Late referrals independently predicted the lack of modality selection (1.847 [1.007, 3.388]). CONCLUSIONS: A structured PEP seemed to improve early dialysis outcomes and resource usage beyond that gained by a timely referral, except for the opportunity to select modality.

Aged↗
PubMedDate not supplied

Multidisciplinary chronic kidney disease management improves survival on dialysis.

BACKGROUND: Delayed nephrology referral is associated with increased morbidity and mortality after patients begin dialysis. However, whether a pre-dialysis educational program (PEP) confers any survival advantage in comparison to unstructured specialist care is not established. METHODS: Cox's regression analysis was used to estimate the association between the type of pre-dialysis follow-up and mortality in all consecutive end-stage renal disease (ESRD) adults starting dialysis therapy in two centers, between 1 January 1999 and 30 June 2002, and followed until 30 June 2003. RESULTS: 229 patients participated in the study. The patients tended to be male (62%), elderly (median age 70 yrs) and to have cardiovascular diseases (60%). Median follow-up on dialysis was 37.8 months, with 624 patient-yrs at risk and a 0.15 yr(-1) mortality rate. Patients receiving regular unstructured care (22.7%) appeared to have similar risk for death as late referrals (36.7%), while PEP patients (40.6%) showed longer survival (hazard ratio 0.48 (95% CI 0.27, 0.87)), allowing for demographics, comorbidities, duration of the pre-dialysis follow-up and dialysis modality. Planned dialysis commencement, a better metabolic status at dialysis initiation and the previous use of angiotensin converting enzyme inhibitors were the main factors associated with improved outcomes. The survival advantage associated with PEP was still present after late referrals or observation for < or = 1 yr were excluded, as well as when survival analysis was limited to the 1st year after dialysis initiation. CONCLUSION: A multidisciplinary approach to chronic kidney diseases seems more effective than just timely referral to nephrologists in improving patient survival on dialysis.

Aged↗
PubMedDate not supplied

Factors associated with unsuccessful utilization and early failure of the arterio-venous fistula for hemodialysis.

BACKGROUND: Arteriovenous fistulae survive longer than grafts and catheters. However, their short term outcomes may not be as good. We sought to determine whether fistulae created in patients referred to a nephrologist less than 3 months before dialysis start show higher risk of unsuccessful use and early failure. METHODS: All patients receiving a new vascular access over a six-year period at three centres were enrolled. Logistic and Cox's regression techniques were used to model late referral on successful utilization for <6 consecutive HD-sessions and time to failure within the first month from access creation, adjusting for demographics, comorbidities and surgical strategies. RESULTS: Among the 535 subjects enrolled, 513 received a fistula. Without considering revisions, 119 fistulae (23.2%) were not successfully used and 61 (11.9%) failed early. Independent predictors of unsuccessful utilization were late referral (Odds Ratio 2.15 [95% Confidence Interval 1.23, 3.75]), vascular diseases (1.86 [1.16, 2.97]), absence of treated hypertension (2.07 [1.17, 3.68]), and heart failure limited to late referrals (10.74 [4, 28.82]). Late referral (Hazard Ratio 1.72 [1.05, 2.81]), absence of treated hypertension (1.80 [1.02, 3.18]) and heart failure (2.34 [1.34, 4.08]) also predicted primary early failure. CONCLUSIONS: Late patient referral and presence of cardiovascular diseases, particularly heart failure, are potentially modifiable risk factors for short-term outcomes improvement of hemodialysis fistulae.

Aged↗