Systematic literature review and meta-analysis on use of Thrombopoietic agents for chemotherapy-induced thrombocytopenia.

BACKGROUND: Currently, there are no approved options to prevent or treat chemotherapy-induced thrombocytopenia (CIT). We performed a systematic literature review and meta-analysis on use of thrombopoietic agents for CIT. PATIENTS AND METHODS: We searched Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed, EMBASE, ClinicalTrials.gov, and health technology assessments from January 1995 to March 2021 for studies evaluating thrombopoietic agents for CIT, including recombinant human thrombopoietin (rhTPO), megakaryocyte growth and development factor (MGDF), romiplostim, and eltrombopag. Random effects meta-analyses were conducted for efficacy and safety endpoints. RESULTS: We screened 1503 titles/abstracts, assessed 138 articles, and abstracted data from 39 publications (14 recombinant human thrombopoietin, 7 megakaryocyte growth and development factor, 9 romiplostim, 8 eltrombopag, and 1 romiplostim/eltrombopag). Random effects meta-analyses of data from multiple studies comparing thrombopoietic agents versus control (comparator, placebo, or no treatment) showed that thrombopoietic agents did not significantly improve chemotherapy dose delays and/or reductions (21.1% vs 40.4%, P = 0.364), grade 3/4 thrombocytopenia (39.3% vs 34.8%; P = 0.789), platelet transfusions (16.7% vs 31.7%, P = 0.111), grade ≥ 2 bleeding (6.7% vs 16.5%; P = 0.250), or thrombosis (7.6% vs 12.5%; P = 0.131). However, among individual studies comparing thrombopoietic agents with placebo or no treatment, thrombopoietic agents positively improved outcomes in some studies, including significantly increasing mean peak platelet counts (186 x 109/L with rhTPO vs 122 x 109/L with no treatment; P < 0.05) in one study and significantly increasing platelet count at nadir (56 x 109/L with rhTPO vs 28 x 109/L with not treatment; P < 0.05) in another study. Safety findings included thrombosis (n = 23 studies) and bleeding (n = 11), with no evidence of increased thrombosis risk with thrombopoietic agents. CONCLUSION: Our analyses generate the hypothesis that thrombopoietic agents may benefit patients with CIT. Further studies with well-characterized bleeding and platelet thresholds are warranted to explore the possible benefits of thrombopoietic agents for CIT.

Healthcare resource utilization among patients with cold agglutinin disease in Denmark.

OBJECTIVES: Cold agglutinin disease (CAD) is a rare form of autoimmune hemolytic anemia that may manifest in complement-mediated chronic hemolytic anemia, profound fatigue, and transient agglutination-mediated circulatory symptoms. This study compared the healthcare resource utilization (HRU) of patients with CAD with a matched non-CAD comparison cohort using national Danish health registry data. METHODS: All cases of CAD were identified from 1 January 1999 to 30 June 2016, in the Danish National Patient Registry using the International Classification of Diseases, Tenth Revision, discharge diagnosis codes. A subcohort of patients with primary CAD was identified based on the absence of secondary predisposing concomitant diseases. CAD cases were matched to individuals without CAD from the general population based on birth year, sex, and 19 disease categories of the Charlson Comorbidity Index. Comparative analyses assessed inpatient hospitalizations, outpatient clinic visits, emergency room visits, transfusion use, and expensive drug use between cohorts 6 months before and 12 months after the admission date of the first hospital visit with CAD diagnosis (index date). RESULTS: A total of 104 patients with CAD were matched to 1003 comparison cohort members. Throughout the 12 months after the index date, patients with CAD were more likely to have at least one inpatient hospitalization (odds ratio [OR], 3.9; 95% confidence interval [CI], 2.5-6.0), outpatient clinic visit (OR, 17.2; 95% CI, 6.8-43.1), and blood transfusion (OR, 93.0; 95% CI, 33.3-259.8) than matched comparisons. HRU was similarly higher among patients with CAD than matched comparisons during the 6 months before the index date. Findings were similar among patients with primary CAD. CONCLUSIONS: Characterization of HRU among European patients with CAD has not previously been conducted. This study shows that patients with CAD utilize significant resources in Denmark. Increased HRU uses among patients with CAD before diagnosis presents opportunities for earlier diagnosis and management.

Costs Attributable to Arteriovenous Fistula and Arteriovenous Graft Placements in Hemodialysis Patients with Medicare coverage.

INTRODUCTION: Hemodialysis (HD) in end-stage renal disease (ESRD) patients requires vascular access (VA) through an arteriovenous fistula (AVF), a prosthetic arteriovenous graft (AVG), or a central venous catheter. While AVF or AVG is commonly used for HD, the economic implications of AVF versus AVG use have not been fully established. We describe the healthcare resource utilization and costs of AVF and AVG use for incident ESRD patients in the United States. METHODS: This observational cohort study of AVF and AVG placements used data from the United States Renal Data System to identify and follow access placements. AVF and AVG placements after ESRD onset for incident patients from 2012 to 2014 with continuous Medicare primary coverage were included. All-cause and access-related Medicare costs were averaged over the placement lifetime and expressed as per dialysis-month costs. RESULTS: The analysis included 38,035 AVF placements and 12,789 AVG placements. Total all-cause monthly costs for AVF averaged USD 8,508; mean monthly costs were USD 3,027 for inpatient (IP), USD 3,139 for outpatient (OP), USD 1,572 for physician services, and USD 770 for other care settings. Access-related monthly costs averaged USD 1,699 and represented 20% of all-cause charges for AVFs. Mean all-cause monthly costs for AVG were USD 9,605; by setting monthly costs were USD 3,811 for IP, USD 3,034 for OP, USD 1,881 for physician services and USD 879 for other care settings. Access-related monthly costs averaged USD 2,656 and represented 28% of all-cause charges for AVGs. DISCUSSION/CONCLUSIONS: This study indicates that costs due to VA are a significant burden on Medicare budgets and on patients. The factors driving access-related utilization and costs merit attention in future research. Both optimizing process of care and discovery innovation may significantly accelerate better stewardship of available healthcare resources.

Clinical Outcomes of Arteriovenous Access in Incident Hemodialysis Patients with Medicare Coverage, 2012-2014.

BACKGROUND: Chronic hemodialysis requires a mode of vascular access through an arteriovenous fistula (AVF), a prosthetic arteriovenous graft (AVG), or a central venous catheter (CVC). AVF is recommended over AVG or CVC due to increased patency and decreased intervention rates for those that mature. AVG are preferred over CVC due to decreased infection and mortality risk. The aims of this study were to evaluate the lifespan of AVF and AVG in maturation, sustained access use, and abandonment. METHODS: The United States Renal Data System (USRDS), Medicare claims, and CROWNWeb were used to identify access placements. Patients with a first end-stage renal disease (ESRD) service from January 1, 2012 to June 30, 2014 with continuous coverage with Medicare as primary payer and ≥1 AVF or AVG placed after ESRD onset were included. Maturation was defined as the first use of the access for hemodialysis recorded in CROWNWeb. Sustained access use was defined as 3 consecutive months of use without catheter placement or replacement. Accesses that were never used at any time post-placement were considered abandoned. RESULTS: The cohort included 38,035 AVF placements and 12,789 AVG placements. Sixty-nine percent of AVF and 72% of AVG matured. Fifty-two percent of AVF and 51% of AVG achieved sustained access use. One quarter of AVF and 14% of AVG were abandoned without use as recorded in CROWNWeb. CONCLUSION: Although considered the gold standard for vascular access, only half of AVF and AVG placements achieved sustained access use. The USRDS database has inherent limitations but provides useful clinical insight into maturation, sustained use, and abandonment.

Patterns of Bicalutamide Use in Prostate Cancer Treatment: A U.S. Real-World Analysis Using the SEER-Medicare Database.

INTRODUCTION: Bicalutamide (BIC), a non-steroidal anti-androgen, is FDA-indicated for use in combination with a luteinizing hormone-releasing hormone (LHRH) analog for treatment of Stage D2 metastatic carcinoma of the prostate. Lack of consensus exists regarding the clinical benefit of BIC use, either alone or combined use of BIC with an LHRH analog or antagonist (combined androgen blockade or CAB), versus treatment with androgen deprivation therapy (ADT) alone. METHODS: The SEER-Medicare database was used to identify prostate cancer patients aged ≥ 66 years diagnosed between 2007 and 2011 and who filled at least one prescription for BIC. Duration of BIC treatment was assessed in relation to ADT use; either alone (monotherapy), as part of CAB only, and as part of CAB followed by monotherapy. Additionally, we assessed use of BIC during or outside a potential testosterone flare prevention period (initiation within 2 months of an LHRH agonist). RESULTS: A total of 7521 prostate cancer patients who filled a prescription for BIC were identified. Eighteen percent of the cohort used BIC alone, over half the patients (54%) used BIC as part of CAB and 27% used BIC as part of CAB followed by monotherapy. Among men treated with BIC as part of CAB, 58% received BIC only within the potential flare period. CONCLUSIONS: Although there is no FDA indication for BIC use as monotherapy, > 44% of patients in this study used BIC alone or as part of CAB followed by monotherapy. Further research is necessary to understand the outcomes of BIC utilization in these settings, particularly compared with newer second-generation anti-androgens. FUNDING: Medivation LLC, a Pfizer company, and Astellas, Pharma, Inc.

Clinical and economic burden associated with stage III to IV triple-negative breast cancer: A SEER-Medicare historical cohort study in elderly women in the United States.

BACKGROUND: The current study was performed to describe patient characteristics, treatment patterns, survival, health care resource use (HRU), and costs among older women in the United States with advanced (American Joint Committee on Cancer stage III/IV) triple-negative breast cancer (TNBC) in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. METHODS: Women who were aged ≥66 years at the time of diagnosis and diagnosed with advanced TNBC between January 1, 2007, and January 1, 2011, in the SEER-Medicare database and who were followed for survival through December 31, 2013, were eligible. Patient demographic and clinical characteristics at the time of diagnosis, subsequent treatment patterns, and survival outcomes were analyzed. HRU and costs for the first 3 months after diagnosis, the last 3 months of life, and the time in between are summarized. All analyses were stratified by American Joint Committee on Cancer stage of disease. RESULTS: There were 1244 patients newly diagnosed with advanced TNBC; the majority were aged ≥75 years (61% with stage III disease and 57.4% with stage IV disease) and white (>70% of patients in both disease stage groups). The most common treatment approaches were surgery combined with chemotherapy for patients for stage III disease (50.6%) and chemotherapy alone or with radiotherapy for patients with stage IV disease (31.3%). Diverse chemotherapy regimens were administered for each line of therapy; nevertheless, the medications used were consistent with national guidelines. Patients with stage III and stage IV disease were found to have a similar mean number of hospitalizations and outpatient visits, but mean monthly costs were greater for patients with stage IV disease at all 3 time points. The mean cost per patient-month (in 2013 US dollars) was $4810 for patients with stage III disease and $9159 for patients with stage IV disease. CONCLUSIONS: Among older women with advanced TNBC, significant treatment variations and considerable HRU and costs exist. Further research is needed to find effective treatments with which to reduce the clinical and economic burden of this disease. Cancer 2018;124:2104-14. © 2018 American Cancer Society.

Historical cancer incidence and mortality assessment in an Illinois community proximal to a former manufactured gas plant.

OBJECTIVES: Concern has been raised that the occurrence of cancer may be increased in neighbourhoods around a former manufactured gas plant in Champaign, Illinois, USA. Thus, we compared historical rates of cancer in this area to comparison communities as well as with nationally standardised rates. DESIGN: Retrospective population-based community cancer assessment during 1990-2010. SETTING: Champaign County, Illinois, USA, and zip codes encompassing the location of the former manufactured gas plant to counties that were similar demographically. PARTICIPANTS: Residents of the counties and zip codes studied between 1990 and 2010. MAIN OUTCOME MEASURES: The relative risk (RR) and 95% CI were used to compare cancer incidence and mortality in the areas near the gas compression site to the comparison counties. Standardised incidence ratios (SIRs) were calculated to compare rates in the areas near the gas compression site to expected rates based on overall US cancer rates. RESULTS: Total cancer mortality (RR=0.91, 95% CI 0.88 to 0.94) and incidence (RR=0.95, 95% CI 0.94 to 0.97) were reduced significantly in Champaign County versus the comparison counties. Similarly, a reduced rate of total cancer was observed in analyses by zip code (proximal to the former gas plant) when compared with either similar counties (RR=0.89, 95% CI 0.86 to 0.93) or national standardised rates of cancer (SIR=0.88, 95% CI 0.85 to 0.91). CONCLUSIONS: This historical cancer assessment did not find an increased risk of total cancer or specific cancer types in communities near a former manufactured gas plant site.

Health resource utilization and cost associated with myeloproliferative neoplasms in a large United States health plan.

Myelofibrosis (MF), polycythemia vera (PV) and essential thrombocythemia (ET) may lead to bone marrow fibrosis. Because the disease course of ET and PV are long and the disease course of MF may be fatal, healthcare resource utilization (HRU) associated costs of these neoplasms are especially important to understand. We used a large US health insurance claim database to describe the costs of these diseases. Compared to age-gender matched comparisons without myeloproliferative neoplasms (MPN), all aspects of HRU that we examined, including inpatient, outpatient and emergency room visits and pharmacy, as well as overall healthcare expenditures, were significantly higher in patients with MF, PV and ET (e.g. MF total costs = $54 168 vs. $10 203; PV = $14 903 vs. $7913; ET = $29 553 vs. $8026) than in matched comparisons. In order to reduce the burden of illness associated with these diseases, continued efforts in the development of more efficacious treatments for these disorders are needed.

Hospitalization with acute exacerbation of chronic obstructive pulmonary disease and associated health resource utilization: a population-based Danish cohort study.

OBJECTIVE: Health resource utilization (HRU) and outcomes associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are not well described. Therefore, a population-based cohort study was conducted to characterize patients hospitalized with AECOPD with regard to HRU, mortality, recurrence, and predictors of readmission with AECOPD. METHODS: Using Danish healthcare databases, this study identified COPD patients with at least one AECOPD hospitalization between 2005-2009 in Northern Denmark. Hospitalized AECOPD patients' HRU, in-hospital mortality, 30-day, 60-day, 90-day, and 180-day post-discharge mortality and recurrence risk, and predictors of readmission with AECOPD in the year following study inclusion were characterized. RESULTS: This study observed 6612 AECOPD hospitalizations among 3176 prevalent COPD patients. Among all AECOPD hospitalizations, median length of stay was 6 days (interquartile range [IQR] 3-9 days); 5 days (IQR 3-9) among those without ICU stay and 11 days (IQR 7-20) among the 8.6% admitted to the ICU. Mechanical ventilation was provided to 193 (2.9%) and non-invasive ventilation to 479 (7.2%) admitted patients. In-hospital mortality was 5.6%. Post-discharge mortality was 4.2%, 7.8%, 10.5%, and 17.4% at 30, 60, 90, and 180 days, respectively. Mortality and readmission risk increased with each AECOPD hospitalization experienced in the first year of follow-up. Readmission at least twice in the first year of follow-up was observed among 286 (9.0%) COPD patients and was related to increasing age, male gender, obesity, asthma, osteoporosis, depression, myocardial infarction, diabetes I and II, any malignancy, and hospitalization with AECOPD or COPD in the prior year. LIMITATIONS: The study included only hospitalized AECOPD patients among prevalent COPD patients. Furthermore, information was lacking on clinical variables. CONCLUSION: These findings indicate that AECOPD hospitalizations are associated with substantial mortality and risk of recurrence.

The burden of immune thrombocytopenia in adults: evaluation of the thrombopoietin receptor agonist romiplostim.

BACKGROUND: Immune thrombocytopenia (ITP) is a chronic, immune-mediated disease characterized by a transient or long-lasting decrease in platelet counts. ITP is associated with numerous serious clinical consequences. Discussed here are clinical aspects of ITP, the humanistic and economic burden of ITP, and current treatment options with a focus on romiplostim, a thrombopoietin (TPO) receptor agonist. The aim of this review is to provide decision-makers with the background information necessary to evaluate the value of romiplostim. SCOPE: PubMed was searched for relevant, English-language papers published from January 2006 through November 2011 relating to the epidemiology and treatment options of chronic ITP, and, focusing on the TPO mimetic romiplostim, patient-reported outcomes (PRO) and economic burden. Recent select conference abstracts were also reviewed. FINDINGS: The initial clinical management of ITP (e.g., corticosteroids, immunoglobulins) is often associated with adverse events and recommended for short-term use only. Splenectomy, a potentially curative second-line treatment, is associated with increased risks of bleeding and infection, and patients often require additional long-term drug intervention. ITP and its sequelae are associated with a substantial burden on patients' health-related quality-of-life (HRQoL) and increased medical costs. Use of TPO receptor agonists in ITP patients may represent a more efficient use of healthcare resources than existing therapies. CONCLUSION: While this literature review is not a systematic review, e.g., it considers only approved therapies and published literature written in English, it provides a comprehensive overview of the clinical, humanistic, and economic factors that should be considered in treating ITP, particularly with new agents such as romiplostim. Among the limited number of safe and effective therapies currently available for chronic ITP, highly effective and well-tolerated medications such as romiplostim may reduce the healthcare resource utilization associated with ITP while improving patients' HRQoL.

Incidence of myelodysplastic syndromes within a nonprofit healthcare system in western Washington state, 2005-2006.

Myelodysplastic syndromes (MDS) incidence is unclear because of historical lack of population-based registration and possibly because of underdiagnosis. We conducted a study to evaluate completeness of MDS registration in the Seattle-Puget Sound region of the Surveillance, Epidemiology, and End Results (SEER) program-which has reported the highest rates among the SEER registries since mandatory reporting of MDS began in 2001. We identified incident MDS cases of any age that occurred within a nonprofit healthcare system in western Washington State in 2005 or 2006 through the local SEER registry or by relevant diagnostic code followed by medical chart review to classify these patients as unlikely, possible, or definite/probable MDS. We calculated age-standardized incidence rates for all identified MDS cases and for case groups based on identification method, and we summarized medical histories of the MDS patients. MDS incidence in our study population was estimated as 7.0 per 100,000 person-years in 2005-2006 when combining MDS cases identified by SEER and definite/probable cases identified by chart review, which was similar to the rate of 6.9 reported by our local SEER registry. The addition of possible MDS cases identified from chart review increased the rate to 10.2 per 100,000. MDS patients frequently had previous cancer diagnoses (25%) and comorbidities such as high blood pressure and diabetes. Our investigation suggests that although reporting of confirmed MDS diagnoses in our region appears complete, MDS incidence is likely underestimated because of omission of cases who are symptomatic but do not receive definitive diagnoses.

Characteristics of US patients with myelodysplastic syndromes: results of six cross-sectional physician surveys.

BACKGROUND: Myelodysplastic syndromes (MDS) comprise a group of pathologically and cytogenetically distinct bone marrow disorders. Little is known about the characteristics of MDS patients, including their pathological and prognostic classifications, cytopenias, transfusion and supportive care needs, and treatment regimens. We describe these characteristics in a large group of recently diagnosed and existing (ie, established) MDS patients. METHODS: We conducted six consecutive cross-sectional surveys among US hematology and medical oncology specialists (identified from an American Medical Association [AMA] database of physicians who administer chemotherapy) between June 2005 and January 2007. A questionnaire collected data on the characteristics and treatment patterns of the 4-10 most recently seen MDS patients for each physician, including demographic data, transfusion needs, treatment approaches, and consideration for clinical trials or bone marrow transplantation. RESULTS: A panel of 101 physicians who were geographically representative of physicians registered with the AMA characterized 614-827 patients per survey, for a total of 4514 responses. Among recently diagnosed patients, 55% were male (95% confidence interval [CI] = 52% to 59%), the median age at diagnosis was 71 years (range = 65-80 years), and 10% (95% CI = 8% to 12%) had MDS secondary to chemotherapy, radiation therapy, or environmental exposure. The median duration of MDS in established patients ranged from 13 to 16 months over the six surveys. Among recently diagnosed MDS patients, fewer patients with lower-risk disease than with higher-risk disease were dependent on either red blood cell transfusions (22% vs 68%) or platelet transfusions (6% vs 33%). More than 50% of all newly diagnosed and established patients used erythropoiesis-stimulating agents. A small percentage of all patients either had had or were being considered for bone marrow transplantation (recently diagnosed: 4%; established: 4% or less) or were being treated on clinical trials (recently diagnosed: 1%; established: 4% or less). CONCLUSIONS: MDS patients in the United States have substantial transfusion needs, and use of erythropoiesis-stimulating agents and are seldom considered for bone marrow transplantation or clinical trials. These data may be useful in characterizing the health care resource use and pharmacoeconomic impact of MDS in the United States.

The Danish Registry for Plastic Surgery of the Breast: establishment of a nationwide registry for prospective follow-up, quality assessment, and investigation of breast surgery.

Although numerous epidemiologic studies have examined the long-term safety of silicone breast implants during the past decade, there is a relative lack of surveillance data on short-term health effects and complications following cosmetic surgery of the breast. The Danish Registry for Plastic Surgery of the Breast, established in May of 1999, provides plastic surgeons with a nationwide system for the collection of preoperative, perioperative, and postoperative data on women undergoing breast implantation, breast reduction, or mastopexy. The purpose of the Registry is to examine short-term and, eventually, long-term local complications and possible health effects, and to contribute to an ongoing evaluation of surgical results and surveillance of the products. Furthermore, the Registry will allow the identification of new areas for research into cosmetic and reconstructive breast surgery. Women accepting registration in the Danish Registry for Plastic Surgery of the Breast complete a self-administered questionnaire focusing on medical history and demographic and behavioral factors. Preoperative blood samples are drawn for storage. Surgical data, postoperative results, and complications are registered following surgery and at postoperative visits. Currently, registration has been initiated at 24 private and public clinics, representing more than 80 percent of the plastic surgery clinics in Denmark. As of November of 2001, a total of 1472 women with breast implants and 560 women with breast reduction were included in the Registry. These figures are expected to increase annually by 1000 women undergoing breast implantation and 500 women undergoing breast reduction or mastopexy. The authors present their experience of establishing the first nationwide comprehensive clinical-epidemiologic database and biological bank for cosmetic and reconstructive surgery procedures.

Characteristics of women with cosmetic breast implants compared with women with other types of cosmetic surgery and population-based controls in Denmark.

Herein the authors describe characteristics of women with breast implants compared with women with other types of cosmetic surgery as well as population controls. All women who acquired breast implants from 1977 to 1997 were identified from the files of two private plastic surgery clinics in Denmark. Patient characteristics were obtained through a self-administered questionnaire. The magnitude of differences between patient and control groups was estimated using odds ratios and 95% confidence intervals. Women with breast implants had a significantly lower body mass index and reported a two-fold greater incidence of current smoking compared with women from the general population and compared with women with other cosmetic surgery. Women with implants reported a greater number of full-term pregnancies and were less likely than controls to have had their first birth at age 30 years or older. Women with implants were not more likely than women in either control group to report a history of diseases, including connective tissue diseases, cancer, or depression before their implant surgery. Women with cosmetic breast implants differ from women with other forms of cosmetic surgery and from general population controls with respect to characteristics that may importantly influence health outcomes and that need to be addressed in future breast implant studies.

Socio-economic status and chronic renal failure: a population-based case-control study in Sweden.

BACKGROUND: Low socio-economic status is associated with the occurrence of several different chronic diseases, but evidence regarding renal disease is scant. To explore whether the risk of chronic renal failure varies by socio-economic status, we performed a population-based case-control study in Sweden. METHODS: All native residents from May 1996 to May 1998, aged 18-74 years, formed the source population. Cases (n = 926) were incident patients with chronic renal failure in a pre-uraemic stage. Control subjects (n = 998) were randomly selected within the source population. Exposures were assessed at personal interviews and relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for age, sex, body mass index (BMI), smoking, alcohol consumption and regular analgesics use. RESULTS: In families with unskilled workers only, the risk of chronic renal failure was increased by 110% [OR = 2.1; 95% confidence interval (CI), 1.1-4.0] and 60% (OR = 1.6; 95% CI, 1.0-2.6) among women and men, respectively, relative to subjects living in families in which at least one member was a professional. Subjects with 9 years or less of schooling had a 30% (OR = 1.3; 95% CI, 1.0-1.7) higher risk compared with those with a university education. The excess risk was of similar magnitude regardless of underlying renal disease. CONCLUSIONS: Low socio-economic status is associated with an increased risk of chronic renal failure. The moderate excess was not explained by age, sex, BMI, smoking, alcohol or analgesic intake. Thus, socio-economic status appears to be an independent risk indicator for chronic renal failure in Sweden.