BIC extensions for order-constrained model selection.

The Schwarz or Bayesian information criterion (BIC) is one of the most widely used tools for model comparison in social science research. The BIC however is not suitable for evaluating models with order constraints on the parameters of interest. This paper explores two extensions of the BIC for evaluating order constrained models, one where a truncated unit information prior is used under the order-constrained model, and the other where a truncated local unit information prior is used. The first prior is centered around the maximum likelihood estimate and the latter prior is centered around a null value. Several analyses show that the order-constrained BIC based on the local unit information prior works better as an Occam's razor for evaluating order-constrained models and results in lower error probabilities. The methodology based on the local unit information prior is implemented in the R package 'BFpack' which allows researchers to easily apply the method for order-constrained model selection. The usefulness of the methodology is illustrated using data from the European Values Study.

Dealing with loss: food and eating in women with ovarian cancer on parenteral nutrition.

BACKGROUND: Malignant bowel obstruction is a common complication of ovarian cancer, resulting in limited oral intake. Home parenteral nutrition (HPN) may be offered to patients in this condition to meet nutritional requirements. However, it is not known how they experience being unable to eat. The present study reports how patients related to food when receiving HPN. METHODS: The investigation was a qualitative study underpinned by phenomenology with women with advanced ovarian cancer in bowel obstruction receiving parenteral nutrition. Interview transcripts were analysed thematically guided by the techniques of Van Manen. RESULTS: We recruited 20 women to the study. Participants were interviewed a maximum of four times and a total of 39 in-depth longitudinal interviews were conducted. Participants could tolerate minimal amounts of food, if they had a venting gastrostomy. Not being able to eat engendered a sense of sadness and loss, and most women found it challenging to be in the presence of others eating. They adopted strategies to cope, which included fantasising about food and watching cookery programmes. These approaches were not a long-term solution; either participants came to terms with their loss or the strategies became less effective in providing relief. CONCLUSIONS: Home parenteral nutrition meets the nutritional requirements of patients with malignant bowel obstruction but cannot replace the non-nutritive functions of food. Healthcare professionals can offer a patient-centred approach by acknowledging the difficulties that patients may face and, wherever possible, encourage them to focus on the positive benefits of interacting with people rather than the loss of eating on social occasions.

Predicting relapse prior to transplantation in chronic myeloid leukemia by integrating expert knowledge and expression data.

MOTIVATION: Selecting a small number of signature genes for accurate classification of samples is essential for the development of diagnostic tests. However, many genes are highly correlated in gene expression data, and hence, many possible sets of genes are potential classifiers. Because treatment outcomes are poor in advanced chronic myeloid leukemia (CML), we hypothesized that expression of classifiers of advanced phase CML when detected in early CML [chronic phase (CP) CML], correlates with subsequent poorer therapeutic outcome. RESULTS: We developed a method that integrates gene expression data with expert knowledge and predicted functional relationships using iterative Bayesian model averaging. Applying our integrated method to CML, we identified small sets of signature genes that are highly predictive of disease phases and that are more robust and stable than using expression data alone. The accuracy of our algorithm was evaluated using cross-validation on the gene expression data. We then tested the hypothesis that gene sets associated with advanced phase CML would predict relapse after allogeneic transplantation in 176 independent CP CML cases. Our gene signatures of advanced phase CML are predictive of relapse even after adjustment for known risk factors associated with transplant outcomes.

Linezolid in the treatment of multidrug-resistant tuberculosis.

BACKGROUND: Linezolid is a new antibiotic with activity against Mycobacterium tuberculosis in vitro and in animal studies. Several small case series suggest that linezolid is poorly tolerated because of the side effects of anemia/thrombocytopenia and peripheral neuropathy. To characterize our clinical experience with linezolid, the California Department of Public Health Tuberculosis Control Branch's Multidrug-Resistant Tuberculosis (MDR-TB) Service reviewed cases in which the MDR-TB treatment regimens included linezolid therapy. METHODS: Record review was performed for 30 patients treated with linezolid as part of an MDR-TB regimen. Data were collected on clinical and microbiological characteristics, linezolid tolerability, and treatment outcomes. The dosage of linezolid was 600 mg daily. Vitamin B6 at a dosage of 50-100 mg daily was used to mitigate hematologic toxicity. RESULTS: During 2003-2007, 30 patients received linezolid for the treatment of MDR-TB. Patients had isolates resistant to a median of 5 drugs (range, 2-13 drugs). Of the 30 cases, 29 (97%) were pulmonary; of these 29, 21 (72%) had positive results of acid-fast bacilli smear, and 16 (55%) were cavitary. Culture conversion occurred in all pulmonary cases at a median of 7 weeks. At data censure (31 December 2008), 22 (73%) of 30 patients had successfully completed treatment. Five continued to receive treatment. There were no deaths. Three patients had a poor outcome, including 2 defaults and 1 treatment failure. Side effects occurred in 9 patients, including peripheral and optic neuropathy, anemia/thrombocytopenia, rash, and diarrhea. However, only 3 patients stopped linezolid treatment because of side effects. CONCLUSIONS: Linezolid was well tolerated, had low rates of discontinuation, and may have efficacy in the treatment of MDR-TB.

Consistency for the tree bootstrap in respondent-driven sampling.

Respondent-driven sampling is an approach for estimating features of populations that are difficult to access using standard survey tools, e.g., the fraction of injection drug users who are HIV positive. Baraff et al. (2016) introduced an approach to estimating uncertainty in population proportion estimates from respondent-driven sampling using the tree bootstrap method. In this paper we establish the consistency of this tree bootstrap approach in the case of [Formula: see text]-trees.

Bayesian melding for estimating uncertainty in national HIV prevalence estimates.

OBJECTIVE: To construct confidence intervals for HIV prevalence in countries with generalised epidemics. METHODS: In the Bayesian melding approach, a sample of country-specific epidemic curves describing HIV prevalence over time is derived based on time series of antenatal clinic prevalence data and general information on the parameters that describe the HIV epidemic. The prevalence trends at antenatal clinics are calibrated to population-based HIV prevalence estimates from national surveys. For countries without population based estimates, a general calibration method is developed. Based on the sample of calibrated epidemic curves, we derive annual 95% confidence intervals for HIV prevalence. The curve that best represents the data at antenatal clinics and population-based surveys, as well as general information about the epidemic, is chosen to represent the best estimates and predictions. RESULTS: We present results for urban areas in Haiti and Namibia to illustrate the estimates and confidence intervals that are derived with the methodology.

Progress and challenges in modelling country-level HIV/AIDS epidemics: the UNAIDS Estimation and Projection Package 2007.

The UNAIDS Estimation and Projection Package (EPP) was developed to aid in country-level estimation and short-term projection of HIV/AIDS epidemics. This paper describes advances reflected in the most recent update of this tool (EPP 2007), and identifies key issues that remain to be addressed in future versions. The major change to EPP 2007 is the addition of uncertainty estimation for generalised epidemics using the technique of Bayesian melding, but many additional changes have been made to improve the user interface and efficiency of the package. This paper describes the interface for uncertainty analysis, changes to the user interface for calibration procedures and other user interface changes to improve EPP's utility in different settings. While formal uncertainty assessment remains an unresolved challenge in low-level and concentrated epidemics, the Bayesian melding approach has been applied to provide analysts in these settings with a visual depiction of the range of models that may be consistent with their data. In fitting the model to countries with longer-running epidemics in sub-Saharan Africa, a number of limitations have been identified in the current model with respect to accommodating behaviour change and accurately replicating certain observed epidemic patterns. This paper discusses these issues along with their implications for future changes to EPP and to the underlying UNAIDS Reference Group model.

Quality of life of living kidney donors: a single-center experience.

Renal transplantation improves the quality of life (QoL) of patients with end-stage renal disease. The preservation of QoL of living kidney donors is paramount. The aim of this study was to assess the QoL pre- and postdonation using Medical Outcome Survey Short Form-36 (SF-36) and to compare with a control group of potential donors who did not proceed with donation. Over a period of 28 years (1978 to 2006), 82 living donor renal transplantations were performed. Of the 78 eligible donors, 66 (85%) participated in the survey. The median postdonation period was 4.6 years (range, 3 months to 27 years). Thirty eight individuals were assessed in the control group. The postdonation SF-36 scores of the donors were not statistically significantly different from those of the control group except in one out of eight dimensions, which was physical role. However, in 44/66 (66%) donors, the postdonation scores were significantly lower compared to their predonation scores because of development of comorbidities such as musculoskeletal pain, migraine, myocardial infarction, diabetes, and peptic ulcers as the time progressed since kidney donation. The age, sex, time since donation, and relationship to recipient did not affect QoL. Eighty three percentage of the donors would have donated again if possible, and 90.9% wished to encourage living kidney donation. We conclude that the QoL of living kidney donors was not different from the healthy controls, although with the passage of time, there was some deterioration of QoL due to development of comorbidities.

Renal transplantation after endovascular repair of abdominal aortic aneurysm.

An increasing number of abdominal aortic aneurysms (AAA) occur in renal failure patients because of strong association between atherosclerosis and chronic kidney disease. Endovascular aneurysm repair (EVAR) has proven to be an effective modality to treat AAA, particularly in patients with renal disease, because of its several advantages over the standard open procedure, including lower morbidity, shorter operative time, and shorter hospital stay. A Medline search showed a single publication on renal transplantation (RT) following EVAR of AAA. In this context, we report our case of successful RT in a patient who had undergone EVAR 2 years prior for a 5.7-cm AAA. No stent-related complications, such as graft occlusion, dislodgement, dissection, or endoleak, were observed in the perioperative period. The transplanted kidney had primary function leading to a stable serum creatinine of 115 micromol/L at 6 months. Although the long-term outcome of RT after endovascular repair of AAA remains unknown, currently available evidence shows favorable outcomes of EVAR in the normal population, in patients with renal diseases, and in RT recipients; hence, RT should not be denied to renal failure patients who have undergone EVAR in the past.

The effect of body temperature in a rat model of renal ischemia-reperfusion injury.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is an unavoidable event in renal transplantation; the effects of IRI can be seen in both the acute and long-term function of the transplanted organ. For this reason, research into the pathophysiology of ischemia-reperfusion is at the forefront of transplantation research. Animal models, particularly in the rat, provide a useful research tool in studying the intricacies of IRI and in evaluating new treatments. We describe a model of right nephrectomy and left renal clamping for 45 minutes and demonstrate the effects of temperature variation during the ischemic period. METHODS: Male Sprague-Dawley rats (under isoflurane anesthesia) underwent bilateral flank incision with removal of the right kidney and clamping of the left renal hilum for 45 minutes. The animals were divided into 3 groups (n=6): group 1 had the procedure performed on a heating mat with no temperature control facilities, group 2 used no heating mat, and group 3 used a rectal temperature-controlled homeothermic blanket system (Harvard Medical, United Kingdom). Temperature was taken every 5 minutes throughout the procedure and blood samples were taken on a daily postoperative basis via tail vein venepuncture. RESULTS: The average temperature at the end of the procedure in group 1 was 39.67 degrees C and the creatinine level at day 3 was 574+/-17.84, in group 2 the temperature was 32.6 degrees C and the creatinine level was 115+/-4.06, and in group 3 the temperature was maintained between 36.5 degrees C-37 degrees C and the serum creatinine level was 329+/-19.18. The temperature of the animal during the ischemia phase of IRI significantly affects the severity of injury. Relative hyperthermia resulted in more severe renal injury and unrecoverable acute renal failure, no source of heat led to a relative hypothermia, and reduction of renal injury. Use of the homeothermic heating blanket led to an increase in creatinine level by day 3, indicating a significant ischemic stimulus; however, by day 10 the creatinine level had returned to normal. CONCLUSION: This illustrates the importance of temperature as a variable in animal models of IRI and thus should be clearly stated in all experimental methods to ensure an appropriate ischemic stimulus and for adequate comparisons between various therapeutic interventions.

FTY720 reduces extracellular matrix expansion associated with ischemia-reperfusion induced injury.

BACKGROUND: Ischemia-reperfusion (IR) is one of the strongest nonimmune factors associated with the development of chronic allograft nephropathy (CAN). This effect is often exacerbated by immunosuppressive medications, most notably cyclosporine. Although traditionally the macrophage was thought to stimulate fibroblast activity in CAN, recent evidence supports a role for lymphocytes. FTY720 is a new immunosuppressant that promotes lymphocyte sequestration into lymph nodes and Peyer's patches. This study investigated the effect of FTY720 on renal fibrosis in the rat following an IR insult (IRI). METHODS: A rat model of IRI was used in which male Sprague-Dawley rats (under isoflurane anaesthesia) underwent bilateral flank incision with removal of the right kidney and clamping of the left renal hilum for 45 minutes. Five groups of animals were studied (n=4): nephrectomy only, IRI only, IRI+FTY720 (1 mg/kg/d), IRI+cyclosporine (15 mg/kg/d), and IRI+FTY 720 (1 mg/kg/d) and cyclosporine (15 mg/kg/d). Animals were humanely killed at 30 days. RESULTS: Serum creatinine (SCr) level was significantly reduced in the FTY720-treated animals. IRI alone produced a significant increase in SCr level compared with neprectomized animals (138 micromol/L vs 55 micromol/L; P<.05). This effect was potentiated by treatment with cyclosporine (173 micromol/L vs 55 micromol/L; P<.05). Treatment with FTY720 significantly reduced SCr level in rats following IRI alone (81 micromol/L vs 138 micromol/L; P<.01) and in rats following IRI + cyclosporine (98 micromol/L vs 173 micromol/L; P<.014). Parallel changes were seen in the levels of proteinuria. Fibrosis was assessed using Masson's trichrome (MT) staining. IRI alone produced a significant increase in MT staining compared with nephrectomized animals (0.92 vs 0.03; P<.05). This effect was potentiated by treatment with cyclosporine (1.12 vs 0.92; P=.022). Treatment with FTY720 reduced the level of MT staining in rats following IRI alone (0.34 vs 0.92; P<.05) and in rats following IRI+cyclosporine (70.34 vs 1.12; P<.05). Levels of TGF-beta1 were considerably reduced in FTY720-treated animals (compared with cyclosporine+IRI and IRI only), either alone (196+/-31 pg/mL vs 1105+/-59 pg/mL and 611+/-38; P<.05) or in conjunction with cyclosporine (423+/-26 pg/mL vs 1105+/-59 pg/mL and 611+/-38; P<.05). CONCLUSION: Our study shows that treatment with FTY720 can reduce renal fibrosis as a result of IRI, both alone and in conjunction with cyclosporine. This provides promising evidence for using FTY720 in a calcineurin-free or reduced-dose immunosuppression protocol in an effort to reduce the incidence of CAN.

Vacuum-assisted closure (VAC) therapy in the management of wound infection following renal transplantation.

OBJECTIVES: Wound infection in the setting of immunosuppressed state such as renal transplantation (RT) causes significant morbidity from sepsis, prolongs hospital stay and is expensive. Vacuum-assisted closure (VAC) therapy is a new technique of management of wound based on the principle of application of controlled negative pressure. The aim of this study was to assess the efficacy of VAC therapy in the management of wound infection following RT. MATERIALS AND METHODS: This is a prospective study of a cohort of 180 consecutive RTs performed over a period of 4 years, where the data were retrieved from a prospectively maintained computerised database and case-notes. RESULTS: 9 of 180 (5%) patients developed wound infection following RT which led to cavitations and dehiscence with copious discharge, and refused to heal with conventional treatment. All 9 cases were treated with VAC therapy. The VAC system was removed after a median of 9 (range 3-30) days when discharge from the wound ceased. Four patients were discharged home with portable VAC device and managed on an outpatient basis, where the system was removed after a median 5.5 (range 3-7) days. The median hospital stay after initiation of VAC therapy was significantly shorter (5, range 2-12 days) than on conventional treatment prior to VAC therapy (11, range, 5-20 days) (p=0.003). Complete healing was achieved in all cases. CONCLUSIONS: The use of VAC therapy is an effective and safe adjunct to conventional and established treatment modalities for the management of wound infection and dehiscence following RT. Key words: Renal transplantation, wound infection, vacuum-assisted closure therapy.

An assessment of intrarenal hydrostatic pressure measurements in the diagnosis of acute renal allograft rejection.

Postoperative intrarenal pressure measurements may be an aid to the diagnosis of acute renal transplant rejection, especially in patients treated with cyclosporine. Serial measurements of intrarenal pressure were made in 38 recipients using a fine-needle technique. Thirty-two intraoperative and 207 postoperative measurements were made, and 39 clinical rejection episodes (23 confirmed by biopsy) monitored. Intraoperative pressures in grafts with immediate function (37.4 +/- 4.0 mmHg, mean +/- SEM) were not significantly different from those with delayed function (30.9 +/- 4.8 mmHg), whereas postoperative pressures were greater (P less than 0.01) in kidneys with acute tubular necrosis (29.4 +/- 1.9 mmHg) than in functioning grafts (20.4 +/- 0.9 mmHg). Pressures recorded during clinical rejection episodes (44.3 +/- 2.3 mmHg) exceeded (P less than 0.001) those during quiescent periods (23.6 +/- 1.0 mmHg). During rejection episodes, higher pressures (P less than 0.01) were recorded from tender or palpably enlarged grafts (52.5 +/- 3.0 mmHg) than in the absence of these signs (36.3 +/- 3.1 mmHg), and patients whose transplants biopsies showed cellular rejection tended to have greater pressures (50.1 +/- 4.1 mmHg) than those with concomitant vasculopathy (36.4 +/- 3.9 mmHg), but the latter did not reach statistical significance. In 7 cases of cyclosporine toxicity the intrarenal pressure was 17.8 +/- 4.2 mmHg. Using a diagnostic cut off point of 40 mmHg, the investigation failed to recognize 26% of acute rejection episodes--and, in the presence of acute tubular necrosis, it wrongly categorized 21% of nonrejectors. While its predictive capacity was limited, the test may occasionally be helpful in the differentiation of cyclosporine toxicity and rejection in functioning kidneys.

Thromboxane and prostacyclin synthesis in experimental pancreas transplantation. Changes in parenchymal and vascular prostanoids.

The principal causes of failure of a pancreas transplant are rejection and vascular thrombosis. There is an unusually high attrition rate for pancreas transplants, but study models have been difficult to develop. In a rat model that allows study of acute rejection to the exclusion of nonspecific effects of transplant surgery on the pancreas, in vitro synthesis of prostacyclin (PGI2) and thromboxane A2 (TXA2) by transplanted pancreas and the blood vessels transplanted with it was measured using an RIA for their stable hydrolysis products 6-keto-prostaglandin F1 alpha and thromboxane B2 (TXB2). TXB2 synthesis was significantly greater in allotransplanted pancreas than isotransplanted pancreas from the 5th day after transplantation. Rejection was complete in the allografted group 7-9 days after transplantation. 6-Keto-prostaglandin F1 alpha synthesis was similar in the pancreas for both allografts and isografts. Similar changes were seen in aorta, celiac artery, superior mesenteric artery, and portal vein transplanted with the pancreas. In the transplanted aorta, TXB2 was significantly greater in the allograft group from the third posttransplant day. A group of CsA-treated allografts sampled after 9 days had transplanted pancreatic parenchymal and vascular prostanoid synthesis in the isograft range. The changes in PGI2 and TXA2 synthesis that accompany cellular rejection may mediate vascular failure in rejecting pancreas transplants, and changes in PGI2 and TXA2 synthesis in blood vessels transplanted with the pancreas could promote early vascular thrombosis.

Cortical and vascular prostaglandin synthesis during renal allograft rejection in the rat.

Alterations in local prostacyclin and thromboxane synthesis could mediate the changes in vascular perfusion and platelet deposition in acutely rejecting renal allografts and prostaglandin E2 (PGE2) has been implicated in the regulation of the immune response. 6-Keto-prostaglandin F1 alpha (6 KetoPGF1 alpha), thromboxane B2 (TxB2) (the stable degradation products of prostacyclin and thromboxane A2 [TxA2], respectively) and PGE2 were measured in incubates of cortical slices taken from rat renal allografts or isografts one to seven days after transplantation. 6 KetoPGF1 alpha and TxB2 synthesis was also measured in incubates of blood vessels supplying and transplanted with the kidney in these animals. During the phase of cellular rejection (3-5 days), TxB2 synthesis was selectively elevated in allografted renal cortex, renal artery, renal vein, and abdominal aorta in comparison with isografted tissues. There was also a small but significant rise in cortical PGE2 synthesis at this time, but vascular and cortical 6 KetoPGF1 alpha production remained unchanged. Renal infarction, occurring 7 days after transplantation, was accompanied by a nonspecific rise in the synthesis of all three prostaglandins by renal cortical slices. Increased tissue TxA2 synthesis may contribute to local thrombosis and decreased graft perfusion during acute rejection, thereby potentiating graft destruction.

Method for measuring fibrinolytic activity in a single layer of cells.

A method has been developed for measuring fibrinolytic activity in a single layer of cells--for example, venous endothelium or peritoneal mesothelium. A single layer of cells was collected on a gelatin disc, incubated on a fibrin plate for 24 h, and the resulting area of lysis measured. This was converted to a measure of fibrinolytic activity expressed in Ploug units of urokinase by reference to areas of lysis created by standard amounts of urokinase placed on similar fibrin plates. The method has been used for measuring fibrinolytic activity in venous endothelium and peritoneal mesothelium and has demonstrated that the activity in a single layer of endothelial cells is only about one-quarter of that in an equivalent area of whole vein wall. It has also shown that peritoneal fibrinolytic activity is reduced after peritoneal trauma. This method maybe useful in the investigation of the fibrinolytic system in a variety of pathological conditions--for example, thrombosis and intraperitoneal adhesions.

Peritoneal ultrafiltration after chronic exposure to dialysis fluid.

Eleven rats were given twice-daily intraperitoneal injections of 20 mL of dialysis fluid containing 4.5% glucose for 6 weeks. The peritoneal ultrafiltration capacity of this group was compared with that of a control group of 10 rats that had received no injections by measuring the volume and glucose concentration of the dialysate remaining in the peritoneal cavity 2 hours after injection. Animals that had received injections of dialysis fluid showed significant loss of peritoneal ultrafiltration: volume of dialysate remaining in the control group was 31 (13-35) mL, and in the experimental group was 25 (11-45) mL, with p less than 0.02 (Mann-Whitney). This was associated with enhanced glucose absorption: glucose absorbed by the control group was 382 (312-706) mg, and 595 (435-738) mg in the experimental group (p less than 0.002, Mann-Whitney).

Tenckhoff catheter replacement or intraperitoneal urokinase: a randomised trial in the management of recurrent continuous ambulatory peritoneal dialysis (CAPD) peritonitis.

A randomised trial, comparing Tenckhoff catheter replacement as a one-stage procedure and i.p. urokinase, was undertaken in the management of recurrent continuous ambulatory peritoneal dialysis (CAPD) peritonitis. In addition to appropriate i.p. antibiotic treatment, 17 patients received i.p. urokinase (5000 i.u.) on the second and fourth days of antibiotic treatment, and 14 patients underwent CAPD catheter replacement. An additional six patients also underwent catheter replacement following the recurrence of peritonitis after urokinase treatment. The subsequent recurrence rate of peritonitis following CAPD catheter replacement (5%) was significantly less than after urokinase (41%) (p less than 0.001). Fourteen patients remained free of peritonitis for at least three months after catheter replacement, and five patients were peritonitis-free following urokinase for this period.

Tc-99m labeled HIDA imaging in suspected biliary leaks after liver transplantation.

Tc-99m labeled HIDA imaging has been used to investigate suspected biliary leaks following orthotopic liver transplantation. In two patients the diagnosis of bile leakage was confirmed and appropriate surgical intervention undertaken. In a third patient, despite clinical suspicion, no leakage was apparent on HIDA imaging, and unnecessary surgery was avoided. HIDA imaging is a useful, noninvasive technique for confirming biliary leakage after liver transplantation.

An audit of the surgical workload on a renal unit.

OBJECTIVE: To assess the surgical workload on a renal unit, with particular reference to non-transplant-related surgery and to assess the workload in relation to surgical staffing levels. DESIGN: Prospective audit of all surgical procedures carried out on patients in acute or chronic renal failure, and on transplanted patients, within a one year period. SETTING: A purpose-built renal unit serving a population of 1.7 million. MAIN OUTCOME MEASURES: The number of surgical procedures, both transplant and non-transplant-related, according to type and severity, with particular reference to the levels of surgical staffing. RESULTS: Transplant-related surgery accounted for only 6.5 per cent of the total surgical workload (general, vascular and renal) of the 'transplant surgeons'. Taking into account only the renal-related workload, transplant-related surgery accounted for just 16.5 per cent of the workload, the remainder being related to vascular access and peritoneal access for dialysis, and general surgical procedures on patients in renal failure and transplanted patients. The surgical workload undertaken by a relatively small number of staff was high, representing 531 Intermediate Equivalents per Service Equivalent Value per annum. CONCLUSIONS: When assessing workload and adequacy of surgical staffing on a Renal Unit, care should be taken to account for all surgical activity on renal patients and not just that related to transplantation since only 16.5 per cent of the surgical workload is transplant-related.