Estimating the economic burden of osteoporotic fractures in a multinational study: a real-world data perspective.

Fracture-related costs vary by country. A standardized methodology and presentations were proposed to fairly assess the economic burden of osteoporotic fracture. Results indicated substantial costs of osteoporotic fractures for pharmacy, hospitalization, emergency care, and outpatient visits in women aged ≥ 50 years in Australia, Germany, South Korea, Spain, and the USA. PURPOSE: The objective of this multinational, retrospective matched cohort study was to use a standardized methodology across different healthcare systems to estimate the burden of osteoporotic fracture (OF) in women aged ≥ 50 years in Australia, Germany, South Korea, Spain, and the USA. METHODS: Within each country, healthcare resource utilization and direct costs of care were compared between patients with newly identified OF and a propensity score-matched cohort without OF during follow-up periods of up to 5 years. RESULTS: Across all five countries, the OF cohort had significantly higher rates and length of inpatient admissions compared with the non-OF cohort. In each country, the adjusted total costs of care ratio between OF and non-OF cohorts were significant. The adjusted cost ratios for pharmacy, inpatient care, emergency care, and outpatient visits were similarly higher in the OF cohort across countries. CONCLUSION: The current study demonstrates the substantial economic burden of OF across different countries when compared with matched non-OF patients. The findings would assist stakeholders and policymakers in developing appropriate health policies.

The Capture the Fracture® Partnership: an overview of a global initiative to increase the secondary fracture prevention care for patient benefit.

The Capture the Fracture® Partnership (CTF-P) is a unique collaboration between the International Osteoporosis Foundation, academic units and industry partners to enhance the implementation of effective, efficient fracture liaison services (FLSs) with a good patient experience. CTF-P has generated valuable resources for the specific countries as well as the broader FLS community to improve the initiation, effectiveness and sustainability of FLS in a wide range of healthcare settings.

Infection control in long term care institutions for the elderly: A reflection document on the situation in Spain.

A progressively increasing percentage of the elderly live during the last years of their lives in nursing homes. Although these institutions are intended to mimic life at home as much as possible, they have characteristics that make them quite similar to a "nosocomiun", i.e. an establishment for the treatment of the sick. The very coexistence among the elderly, the fact of sharing caregivers and the very significant exposure to third parties, together with the frequent predisposing diseases to infection in this population, make infection frequent among residents and also easily transmissible. This leads us to ask what can be done to prevent infection in this environment and more specifically what is the state of the art of the matter in a Western European nation such as ours. The Board of Trustees of the Health Sciences Foundation has asked itself a series of questions on the subject of infection prevention in Nursing Homes, the structure of procedures, the legislation available, compliance with the measures indicated, the best indicators of the processes and therefore, the need to promote in Spain a document of recommendations to avoid infections in this poplation whose morbidity and mortality need not be highlighted. To this end, a multidisciplinary group of experts in different aspects of this problem has been convened and asked the proposed questions. The questions were discussed by the group as a whole and led to a series of conclusions agreed upon by the participants. The results of the meeting are reported below.

Genome skimming elucidates the evolutionary history of Octopoda.

Phylogenies for Octopoda have, until now, been based on morphological characters or a few genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata, representing 13 genera and all five putative families of Cirrata (Cirroctopodidae, Cirroteuthidae, Grimpoteuthidae, Opisthoteuthidae and Stauroteuthidae) and six families of Incirrata (Amphitretidae, Argonautidae, Bathypolypodidae, Eledonidae, Enteroctopodidae, and Megaleledonidae) which were assembled using genome skimming. Phylogenetic trees were built using Maximum Likelihood and Bayesian Inference with several alignment matrices. All mitochondrial genomes had the 'typical' genome composition and gene order previously reported for octopodiforms, except Bathypolypus ergasticus, which appears to lack ND5, two tRNA genes that flank ND5 and two other tRNA genes. Argonautoidea was revealed as sister to Octopodidae by the mitochondrial protein-coding gene dataset, however, it was recovered as sister to all other incirrate octopods with strong support in an analysis using nuclear rRNA genes. Within Cirrata, our study supports two existing classifications suggesting neither is likely in conflict with the true evolutionary history of the suborder. Genome skimming is useful in the analysis of phylogenetic relationships within Octopoda; inclusion of both mitochondrial and nuclear data may be key.

A Novel Approach to Tally Aculops cannabicola (Acari: Eriophyidae) for Field and Laboratory Studies.

The hemp russet mite, Aculops cannabicola (Farkas) is a key pest of hemp (Cannabis sativa L.). Given its microscopic size, estimating the size of its populations can be a major limitation to control this pest. Here, we describe a method to count A. cannabicola using photographs taken with a handheld digital microscope. We compared the consistency and strength of the relationship between photographic- and microscope-based counts of mites from infested plants. Among the three sections of the leaflet, the maximum consistency levels were observed in the proximal (50%) and middle photographs (50%). However, it reached from 64% to 100% when the three sections were considered. Photographic and a microscope-based counts were positively correlated (>0.7). A single photograph can be a good predictor of the total mites per leaflet, however, using two pictures (proximal and middle sections) will increase the consistency of the abundance of A. cannabicola per leaflet. A minimum of 22 leaflets per sampling event can support a strong correlation between the microscope and photographic counts. Our method requires low budget and training and takes short time (0.4 to 1.3 min per leaflet) to count mites per sample. Additionally, photographs can be stored on a smartphone, computer, or tablet, allowing users to share, store and process the photos. This method simplifies counts of A. cannabicola on hemp for research purposes and provides a practical tool for growers to assess mite populations for management decisions. In addition, it may be useful for monitoring eriophyid mites on cultivated plants.

The soft X-ray monochromator at the SASE3 beamline of the European XFEL: from design to operation.

The SASE3 soft X-ray beamline at the European XFEL has been designed and built to provide experiments with a pink or monochromatic beam in the photon energy range 250-3000 eV. Here, the focus is monochromatic operation of the SASE3 beamline, and the design and performance of the SASE3 grating monochromator are reported. The unique capability of a free-electron laser source to produce short femtosecond pulses of a high degree of coherence challenges the monochromator design by demanding control of both photon energy and temporal resolution. The aim to transport close to transform-limited pulses poses very high demands on the optics quality, in particular on the grating. The current realization of the SASE3 monochromator is discussed in comparison with optimal design performance. At present, the monochromator operates with two gratings: the low-resolution grating is optimized for time-resolved experiments and allows for moderate resolving power of about 2000-5000 along with pulse stretching of a few to a few tens of femtoseconds RMS, and the high-resolution grating reaches a resolving power of 10 000 at the cost of larger pulse stretching.

Modelo matemático optimizado para la predicción y planificación de la asistencia sanitaria por la COVID-19 / Mathematical model optimized for prediction and health care planning for COVID-19

Objetivo: La pandemia de la COVID-19 ha supuesto una amenaza de colapso de los servicios hospitalarios y de unidades de cuidado intensivo (UCI), así como una reducción de la dinámica asistencial de pacientes afectados por otras patologías. El objetivo fue desarrollar un modelo matemático diseñado para optimizar las predicciones relacionadas con las necesidades de hospitalización e ingresos en UCI por la COVID-19. Diseño: Estudio prospectivo. Ámbito: Provincia de Granada (España). Pacientes: Pacientes de COVID-19 hospitalizados, ingresados en UCI, recuperados y fallecidos desde el 15 de marzo hasta el 22 de septiembre del 2020. Intervenciones: Desarrollo de un modelo matemático tipo susceptible, expuesto, infectado y recuperado (SEIR) capaz de predecir la evolución de la pandemia, considerando las medidas de salud pública establecidas. Variables de interés: Número de pacientes infectados por SARS-CoV-2, hospitalizados e ingresados en UCI por la COVID-19.Resultados: A partir de los datos registrados, hemos podido desarrollar un modelo matemático que refleja el flujo de la población entre los diferentes grupos de interés en relación con la COVID-19. Esta herramienta permite analizar diferentes escenarios basados en medidas de restricción socio-sanitarias y pronosticar el número de infectados, hospitalizados e ingresados en UCI. Conclusiones: El modelo matemático es capaz de proporcionar predicciones sobre la evolución de la COVID-19 con suficiente antelación como para poder conjugar los picos de prevalencia y de necesidades de asistencia hospitalaria y de UCI, con la aparición de ventanas temporales que posibiliten la atención de enfermos no-COVID (AU)

Objective: The COVID-19 pandemic has threatened to collapse hospital and ICU services, and it has affected the care programs for non-COVID patients. The objective was to develop a mathematical model designed to optimize predictions related to the need for hospitalization and ICU admission by COVID-19 patients. Design: Prospective study. Setting: Province of Granada (Spain). Population: COVID-19 patients hospitalized, admitted to ICU, recovered and died from March 15 to September 22, 2020. Study variables: The number of patients infected with SARS-CoV-2 and hospitalized or admitted to ICU for COVID-19. Results: The data reported by hospitals was used to develop a mathematical model that reflects the flow of the population among the different interest groups in relation to COVID-19. This tool allows to analyse different scenarios based on socio-health restriction measures, and to forecast the number of people infected, hospitalized and admitted to the ICU. Conclusions:The mathematical model is capable of providing predictions on the evolution of the COVID-19 sufficiently in advance as to anticipate the peaks of prevalence and hospital and ICU care demands, and also the appearance of periods in which the care for non-COVID patients could be intensified (AU)

Mathematical model optimized for prediction and health care planning for COVID-19.

OBJECTIVE: The COVID-19 pandemic has threatened to collapse hospital and ICU services, and it has affected the care programs for non-COVID patients. The objective was to develop a mathematical model designed to optimize predictions related to the need for hospitalization and ICU admission by COVID-19 patients. DESIGN: Prospective study. SETTING: Province of Granada (Spain). POPULATION: COVID-19 patients hospitalized, admitted to ICU, recovered and died from March 15 to September 22, 2020. STUDY VARIABLES: The number of patients infected with SARS-CoV-2 and hospitalized or admitted to ICU for COVID-19. RESULTS: The data reported by hospitals was used to develop a mathematical model that reflects the flow of the population among the different interest groups in relation to COVID-19. This tool allows to analyse different scenarios based on socio-health restriction measures, and to forecast the number of people infected, hospitalized and admitted to the ICU. CONCLUSIONS: The mathematical model is capable of providing predictions on the evolution of the COVID-19 sufficiently in advance as to anticipate the peaks of prevalence and hospital and ICU care demands, and also the appearance of periods in which the care for non-COVID patients could be intensified.

B-esterases characterisation in the digestive tract of the common octopus and the European cuttlefish and their in vitro responses to contaminants of environmental concern.

Cephalopods are a group of marine invertebrates that have received little attention as sentinel species in comparison to other molluscs, such as bivalves. Consequently, their physiological and biochemical xenobiotic metabolism responses are poorly understood. Here we undertake a comparative analysis of the enzymatic activities involved in detoxification reactions and neural transmission in the digestive tract of two commercial cephalopods: the Common octopus, Octopus vulgaris, and the European cuttlefish, Sepia officinalis. For methodological purposes, several common B-esterases (five carboxylesterase (CE) substrates and three cholinesterase (ChE) determinations) were assayed as a proxy of metabolic and neuronal activities, respectively. Four components of the digestive tract in each species were considered: salivary glands, the stomach, the digestive gland and the caecum. The in vitro responses of digestive gland homogenates to model chemicals and contaminants of environmental concern were contrasted between both cephalopod species. The baseline biochemical activities in the four digestive tract components were also determined. Moreover, in order to validate the protocol, purified proteins, recombinant human CE (CE1 and CE2) and purified eel acetylcholinesterase (AChE) were included in the analysis. Overall, carboxylesterase activities were higher in octopus than in cuttlefish, with the activity quantified in the digestive tract components in the following order: digestive gland ≈ caecum > stomach ≈ salivary glands, with higher hydrolysis rates reached with naphthyl-derived substrates. In contrast, cuttlefish hydrolysis rates with ChE substrates were higher than in octopus. This trend was also reflected in a higher sensitivity to CE inhibitors in octopus and to AChE inhibitors in cuttlefish. Given the detoxification character of CEs and its protective role preventing AChE inhibition, octopus could be regarded as more efficiently protected than cuttlefish from neurotoxic exposures. A full characterisation of B-esterases in the digestive tract of the two common cephalopods is also provided.

Validation and comparison of Breast Graded Prognostic Assessment scores in patients with breast cancer and brain metastases

Validation and comparison of Breast Graded Prognostic Assessment scores in patients with breast cancer and brain metastases (AU)

Mathematical model optimized for prediction and health care planning for COVID-19. / Modelo matemático optimizado para la predicción y planificación de la asistencia sanitaria por la COVID-19.

OBJECTIVE: The COVID-19 pandemic has threatened to collapse hospital and ICU services, and it has affected the care programs for non-COVID patients. The objective was to develop a mathematical model designed to optimize predictions related to the need for hospitalization and ICU admission by COVID-19 patients. DESIGN: Prospective study. SETTING: Province of Granada (Spain). POPULATION: COVID-19 patients hospitalized, admitted to ICU, recovered and died from March 15 to September 22, 2020. STUDY VARIABLES: The number of patients infected with SARS-CoV-2 and hospitalized or admitted to ICU for COVID-19. RESULTS: The data reported by hospitals was used to develop a mathematical model that reflects the flow of the population among the different interest groups in relation to COVID-19. This tool allows to analyse different scenarios based on socio-health restriction measures, and to forecast the number of people infected, hospitalized and admitted to the ICU. CONCLUSIONS: The mathematical model is capable of providing predictions on the evolution of the COVID-19 sufficiently in advance as to anticipate the peaks of prevalence and hospital and ICU care demands, and also the appearance of periods in which the care for non-COVID patients could be intensified.

Validation and comparison of Breast Graded Prognostic Assessment scores in patients with breast cancer and brain metastases.

PURPOSE: Brain metastases (BM) occur in 15-35% of patients with metastatic breast cancer, conferring poor prognosis and impairing quality of life. Clinical scores have been developed to classify patients according to their prognosis. We aimed to check the utility of the Breast Graded Prognostic Assessment (B-GPA) and its modified version (mB-GPA) and compare them in routine clinical practice. METHODS: This is an ambispective study including all patients with breast cancer BM treated in a single cancer comprehensive center. We analyzed the overall survival (OS) from BM diagnosis until death. The Kaplan-Meier method and Cox proportional hazard regression model were used in the analyses. ROC curves were performed to compare both scores. RESULTS: We included 169 patients; median age was 50 years. HER2-positive and triple negative patients were 33.7% and 20.7%, respectively. At the last follow-up, 90% of the patients had died. Median OS was 12 months (95% confidence interval 8.0-16.0 months). OS was worse in patients with > 3 BM and in patients with triple negative subtype. CONCLUSIONS: In our series, we confirm that B-GPA and mB-GPA scores correlated with prognosis. ROC curves showed that B-GPA and mB-GPA have similar prognostic capabilities, slightly in favor of mB-GPA.

Hospital admissions of patients with osteogenesis imperfecta in the English NHS.

Hospital use by patients with osteogenesis imperfecta was largely unknown. This study found that the English NHS provides a significant number of hospital admissions to these patients, translating into large costs to the NHS. Admissions and costs both increased over time. Children under 14 years old accounted for more of the admissions and costs than any other age group. INTRODUCTION: The aim of this study was to characterise hospital use by patients with osteogenesis imperfecta (OI) in the English National Health Service (NHS). METHODS: Routinely collected aggregate data about all inpatient hospital records from patients with OI were used for the period 1 April 2014 to 31 March 2018. Information was extracted on number of admissions, number of patients, length of stay, and costs. Hospital use was summarised using descriptive statistics, categorising patients into 5-year age groups. RESULTS: There were 16,245 hospital admissions for OI patients during the analysis period, with a total cost to the NHS of £24,052,451. Of the 4370 patients involved, 2700 (62%) were female. Female patients averaged 3.3 admissions per year and male patients 4.4 admissions per year. Patients aged 0 to 14 years old accounted for 54% of all admissions. Those aged 90 to 94 years had the longest average length of stay per admission (10.5 days) of any age group. Elective admissions cost on average £1260 and non-elective admissions £2529. Over the 4-year study period, number of admissions increased on average by 2.1% per year and number of patients by 6.4% per year. CONCLUSION: The treatment of patients with OI is associated with a significant number of hospital admissions at an important cost for the NHS, with both number of admissions and costs increasing over time. Children below the age of 14 years had more admissions at a greater total cost than other ages, while the oldest adults had longer average stays and higher costs per admission.

Physical function in UK adults with osteogenesis imperfecta: a cross-sectional analysis of the RUDY study.

We describe the physical function in adults with osteogenesis imperfecta (OI) and explored clinical and non-clinical factors related to its impairment. Our data showed that physical dysfunction is a common feature of adults with OI, varying by OI severity, and mediated by the presence and quality of pain and fatigue symptoms. INTRODUCTION: There is a paucity of data describing physical function in adults with osteogenesis imperfecta (OI). We investigated the effects of OI and its severity on physical function and explored the relationship between physical function and number of fractures and symptomatology. METHODS: Adults with OI of different types were recruited from the RUDY study, an ongoing UK-based prospective cohort study. Participants completed demographic and clinical questions and questionnaires. These assessed physical function (SF-36), mobility (EQ-5D-5L and NEADL), fatigue (FACIT-F), and pain (SF-MQ-2). Scores were compared using parametric or non-parametric statistical analyses, whereas correlations between outcomes were examined using univariate and multivariate regression analysis. RESULTS: Seventy-eight adults with OI aged 43.5 ± 14.5 years were enrolled (type I, 32; type III, 11; type IV, 10; unknown type, 26). Physical function (PCS, SF-36) was significantly lower in all participants than normative values (p < 0.001) and in type III than type I (p = 0.008). Mobility was significantly different across the types (EQ-5D-EL, p = 0.007; NEADL, p < 0.001), with type III having more severe problems, followed by types IV, unknown, and I. Physical function was associated with OI type (r = 0.26; p = 0.021), presence and quality of pain (r = - 0.57; p < 0.0001), and fatigue (r = - 0.51; p < 0.0001). Multivariate analysis revealed that physical function correlated independently with age, OI type, fatigue, and non-neuropathic pain. CONCLUSIONS: Individuals with OI display a marked deterioration in physical function during adulthood. This impairment varies in severity according to the OI phenotype and is associated with the presence of non-neuropathic pain and fatigue.

Utilization and costs of formal and informal care, home adaptations, and physiotherapy among older patients with hip fracture.

AIMS: This feasibility study investigates the utilization and cost of health resources related to formal and informal care, home adaptations, and physiotherapy among patients aged 60 years and above after hip fracture from a multicentre cohort study (World Hip Trauma Evaluation (WHiTE)) in the UK. METHODS: A questionnaire containing health resource use was completed at baseline and four months post-injury by patients or their carer. Completion rate and mean cost of each health resource item were assessed and sensitivity analysis was performed to derive a conservative estimate of the informal care cost. All costs are presented in 2017/18 pound sterling. RESULTS: A total of 4,183 patients from the WHiTE cohort completed the baseline questionnaire between May 2017 and April 2018, of whom 3,524 (84.2%) completed the four-month health resource section. Estimated mean costs of formal and informal care, home adaptations, and physiotherapy during the four months following injury were £2,843 (SD 5,467), £6,613 (SD 15,146), £706 (SD 1,706) and £9 (SD 33), respectively. Mean cost of informal care decreased to £660 (SD £1,040) in the sensitivity analysis when informal care was capped at 17.2 hours per day. CONCLUSION: Informal care is a significant source of costs after hip fracture and should therefore be included in future economical analyses of this patient group. Our results show that there is considerable variation in the interpretation of time-use of informal care among patients and further work is needed to improve how data regarding informal care are collected in order to obtain a more accurate cost estimate.Cite this article: Bone Joint Res. 2020;9(5):250-257.

The impact of BMI and smoking on risk of revision following knee and hip replacement surgery: evidence from routinely collected data.

OBJECTIVE: The aim of this study was to assess the association of body mass index (BMI) and smoking with risk of revision following total knee replacement (TKR) and total hip replacement (THR). DESIGN: Primary care data, from the Clinical Practice Research Datalink (CPRD), was linked to inpatient hospital records, from Hospital Episode Statistics Admitted Patient Care (HES APC), and covered 1997 to 2014. Parametric survival models, with BMI and smoking status included as explanatory variables, were estimated for 10-year risk of revision and mortality, and were extrapolated to estimate lifetime risk of revision. FINDINGS: TKR and THR cohorts included 10,260 and 10,961 individuals, respectively. For a change in BMI from 25 to 35, the 10-year risk of revision is expected change from 4.6% (3.3-6.4%) to 3.7% (2.6-5.1%) for TKR and 3.7% (2.8-5.1%) to 4.0% (2.8-5.7%) for THR for an otherwise average patient profile. Meanwhile, changing from a non-smoker to a current smoker is expected to change the risk of revision from 4.1% (3.1-5.5%) to 2.8% (1.7-4.7%) for TKR and from 3.8% (2.8-5.3%) to 2.9% (1.9-4.7%) for THR for an otherwise average patient profile. Estimates of lifetime risk were also similar for different values of BMI or smoking status. CONCLUSIONS: Obesity and smoking do not appear to have a meaningful impact on the risk of revision following TKR and THR.

Lifetime risk of knee and hip replacement following a GP diagnosis of osteoarthritis: a real-world cohort study.

OBJECTIVE: The aim of this study was to estimate lifetime risk of knee and hip replacement following a GP diagnosis of osteoarthritis and assess how this risk varies with patient characteristics. METHODS: Routinely collected data from Catalonia, Spain, covering 2006 to 2015, were used. Study participants had a newly recorded GP diagnosis of knee or hip osteoarthritis. Parametric survival models were specified for risk of knee/hip replacement and death following diagnosis. Survival models were combined using a Markov model and lifetime risk estimated for the average patient profile. The effects of age at diagnosis, sex, comorbidities, socioeconomic status, body mass index (BMI), and smoking on risk were assessed. RESULTS: 48,311 individuals diagnosed with knee osteoarthritis were included, of whom 2,561 underwent knee replacement. 15,105 individuals diagnosed with hip osteoarthritis were included, of whom 1,247 underwent hip replacement. The average participant's lifetime risk for knee replacement was 30% (95% CI: 25-36%) and for hip replacement was 14% (10-19%). Notable patient characteristics influencing lifetime risk were age at diagnosis for knee and hip replacement, sex for hip replacement, and BMI for knee replacement. BMI increasing from 25 to 35 was associated with lifetime risk of knee replacement increasing from 24% (20-28%) to 32% (26-37%) for otherwise average patients. CONCLUSION: Knee and hip replacement are not inevitable after an osteoarthritis diagnosis, with average lifetime risks of less than a third and a sixth, respectively. Patient characteristics, most notably BMI, influence lifetime risks.

The SASE1 X-ray beam transport system.

SASE1 is the first beamline of the European XFEL that became operational in 2017. It consists of the SASE1 undulator system, the beam transport system, and the two scientific experiment stations: Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX), and Femtosecond X-ray Experiments (FXE). The beam transport system comprises mirrors to offset and guide the beam to the instruments and a set of X-ray optical components to align, manipulate and diagnose the beam. The SASE1 beam transport system is described here in its initial configuration, and results and experiences from the first year of user operation are reported.

Correlation of the Renal Cortex Volume With the Glomerular Filtration Rate in Live Donors for Renal Transplantation.

INTRODUCTION: As a pretransplantation evaluation, renal function is determined by the glomerular filtration rate (GFR) with the use of renal scintigraphy (RS) and the estimated glomerular filtration rate (eGFR). To date, there are few studies that correlate renal cortex volume with eGFR determined with renal gammagram (GR) and eGFR by equations (Cockroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equation) in Latin American living donors. AIM: This study sought to determine whether there is correlation of the volume of the renal cortex by Herts equation with the GFR determined with renal gammagram (GFR-GR). PATIENTS AND METHODS: This was an analytical, observational, and cross-sectional study. A review of the donor charts from January 1, 2014, to December 1, 2014, with a complete clinical file, kidney measurements, predonation tomography volume, and eGFR by different formulas and by renal scintigraphy. RESULTS: Thirty-three donors were included, 51.5% male and 48.5% female. The mean age was 38.58 ± 10 years, with an average volume of 127.83 ± 28.30 mL, with diethylenetriamine-pentaacetate (DTPA) of 54.80 ± 7.13 mL/min/1.73 m2 in the donated kidney. Spearman correlation showed the best association with the Herts equation (r = 0.346) reaching significance (P = .049) when comparing the different equations against the GFR with DTPA. Using the Bland-Altman method, the lowest variability and best significance was verified with the same equation compared to the other formulas (P = .0002). CONCLUSIONS: There is no consensus regarding which is the best formula for calculating the GFR of both kidneys. Of the different formulas, the one that best correlated with the GFR was the Herts method, which uses the volume of the kidney.