Recruitment into randomised trials of arteriovenous grafts: A systematic review

Although randomised controlled trials (RCT) are considered the optimal form of evidence, there are relatively few in surgery. Surgical RCT are particularly likely to be discontinued with poor recruitment cited as a leading reason. Surgical RCT present challenges over and above those seen in drug trials as the treatment under study may vary between procedures, between surgeons in one unit, and between units in multi-centred RCT. The most contentious and debated area of vascular access remains the role of arteriovenous grafts, and thus the quality of the data that is used to support opinions, guidelines and recommendations is critical. The aim of this review was to determine the extent of variation in the planning and recruitment in all RCT involving AVG. The findings of this are stark: there have been only 31 RCT performed in 31 years, the vast majority of which exhibited major limitations severe enough to undermine the results. This underlines the need for better quality RCT and data, and further inform the design of future studies. Perhaps most fundamental is the planning for a RCT that accounts for the intended population, the uptake of a RCT and the attrition for the significant co-morbidity in this population.

Assessing the influence of graft loss on 4-year patient survival after simultaneous pancreas-kidney transplantation: Kaplan-Meier versus Competing Risk Analysis model

BACKGROUND

Graft loss increases the risk of patient death after simultaneous pancreas-kidney (SPK) transplantation. The relative risk of each graft failure is complex due to the influence of several competing events.

METHODS

This retrospective, single-center study compared 4-year patient survival according to the graft status using Kaplan-Meier (KM) and Competing Risk Analysis (CRA). Patient survival was also assessed according to five eras (Era 1: 2001-2003; Era 2: 2004-2006; Era 3: 2007-2009; Era 4: 2010-2012; Era 5: 2012-2015).

RESULTS

Between 2000 and 2015, 432 SPK transplants were performed. Using KM, patient survival was 86.5% for patients without graft loss (n = 333), 93.4% for patients with pancreas graft loss (n = 46), 43.7% for patients with kidney graft loss (n = 16), and 25.4% for patients with pancreas and kidney graft loss (n = 37). Patient survival was underestimated using KM versus CRA methods in patients with pancreas and kidney graft losses (25.4% vs. 36.2%), respectively. Induction with lymphocyte depleting antibodies was associated with 81% reduced risk (HR.19, 95% CI.38-.98, p = .0048), while delayed kidney function (HR 2.94, 95% CI 1.09-7.95, p = .033) and surgical complications (HR 2.94, 95% CI 1.22-7.08, p = .016) were associated with higher risk of death. Four-year patient survival increased from Era 1 to Era 5 (79% vs. 87.9%, p = .047).

CONCLUSION

In this cohort of patients, kidney graft loss, with or without pancreas graft loss, was associated with higher mortality after SPK transplantation. Compared to CRA, the KM model underestimated survival only among patients with pancreas and kidney graft losses. Patient survival increased over time.

The "Can Do, Do Do" Framework Applied to Assess the Association between Physical Capacity, Physical Activity and Prospective Falls, Subsequent Fractures, and Mortality in Patients Visiting the Fracture Liaison Service

The "can do, do do" framework combines measures of poor and normal physical capacity (PC, measured by a 6 min walking test, can do/can't do) and physical activity (PA, measured by accelerometer, do do/don't do) into four domains and is able to categorize patient subgroups with distinct clinical characteristics, including fall and fracture risk factors. This study aims to explore the association between domain categorization and prospective fall, fracture, and mortality outcomes. This 6-year prospective study included patients visiting a Fracture Liaison Service with a recent fracture. Outcomes were first fall (at 3 years of follow-up, measured by fall diaries), first subsequent fracture, and mortality (at 6 years). Cumulative incidences of all three outcomes were calculated. The association between domain categorization and time to the three outcomes was assessed by uni- and multivariate Cox proportional hazard analysis with the "can do, do do" group as reference. The physical performance of 400 patients with a recent fracture was assessed (mean age: 64 years; 70.8% female), of whom 61.5%, 20.3%, and 4.9% sustained a first fall, sustained a subsequent fracture, or had died. Domain categorization using the "can do, do do" framework was not associated with time to first fall, subsequent fracture, or mortality in the multivariate Cox regression analysis for all groups. "Can't do, don't do" group: hazard ratio [HR] for first fall: 0.75 (95% confidence interval [CI]: 0.45-1.23), first fracture HR: 0.58 (95% CI: 0.24-1.41), and mortality HR: 1.19 (95% CI: 0.54-6.95). Categorizing patients into a two-dimensional framework seems inadequate to study complex, multifactorial outcomes. A personalized approach based on known fall and fracture risk factors might be preferable.

Construction and validation of a prognostic nomogram for predicting cancer-specific survival in patients with intermediate and advanced colon cancer after receiving surgery and chemotherapy

BACKGROUND

Existing predictive models often focus solely on overall survival (OS), neglecting the bias that other causes of death might introduce into survival rate predictions. To date, there is no strict predictive model established for cancer-specific survival (CSS) in patients with intermediate and advanced colon cancer after receiving surgery and chemotherapy.

METHODS

We extracted the data from the Surveillance, Epidemiology, and End Results (SEER) database on patients with stage-III and -IV colon cancer treated with surgery and chemotherapy between 2010 and 2015. The cancer-specific survival (CSS) was assessed using a competitive risk model, and the associated risk factors were identified via univariate and multivariate analyses. A nomogram predicting 1-, 3-, and 5-year CSS was constructed. The c-index, area under the curve (AUC), and calibration curve were adopted to assess the predictive performance of the model. Additionally, the model was externally validated.

RESULTS

A total of 18 risk factors were identified by univariate and multivariate analyses for constructing the nomogram. The AUC values of the nomogram for the 1-, 3-, and 5-year CSS prediction were 0.831, 0.842, and 0.848 in the training set; 0.842, 0.853, and 0.849 in the internal validation set; and 0.815, 0.823, and 0.839 in the external validation set. The C-index were 0.826 (se: 0.001), 0.836 (se: 0.002) and 0.763 (se: 0.013), respectively. Moreover, the calibration curve showed great calibration.

CONCLUSION

The model we have constructed is of great accuracy and reliability, and can help physicians develop treatment and follow-up strategies that are beneficial to the survival of the patients.

Comprehensive causes of death in uveal melanoma: mortality in 1530 consecutively diagnosed patients followed until death

BACKGROUND

Uveal melanoma has a high propensity for metastatic spread. Yet, the comprehensive causes of death in a large consecutive cohort followed from diagnosis to death remain unknown.

METHODS

All Swedish patients diagnosed with melanoma involving the iris, choroid, and/or ciliary body after January 1, 1960, were assessed for this study. Sequential inclusion was halted upon encountering the first surviving patient during data collection. Causes of death were collected from the National Cause of Death Registry and audited by analysis of up to 15 causative diagnoses.

RESULTS

A total of 1530 patients were included, each histopathologically verified with primary uveal melanoma. Mortality from metastatic uveal melanoma was 31% at 5 years, 40% at 10 years, 45% at 20 years, 47% at 30 years, and 48% between 40 and 60 years post-diagnosis. Notably, the longest period between diagnosis and metastatic fatality was 49.6 years. Additionally, 186 other causes of death were recorded, with cardiovascular diseases constituting 26%, other cancers 10%, stroke 6%, dementias 2%, and lower respiratory infections 2% of total mortalities. Mortality from colorectal, lung, prostate, and stomach carcinomas over 60 years were 1.4%, 1.4%, 1.2%, and 0.9%, with metastatic uveal melanoma being the leading cumulative and annual cause of death for the initial 41 and 5 years post-diagnosis, respectively.

CONCLUSIONS

In this large consecutive cohort, half of the included patients ultimately succumbed to metastatic uveal melanoma, with deaths occurring up to 50 years after diagnosis. One-quarter and one-tenth of patients died from cardiovascular diseases and other cancers, respectively.

Imminent fall risk after fracture

RATIONALE

Adults with a recent fracture have a high imminent risk of a subsequent fracture. We hypothesise that, like subsequent fracture risk, fall risk is also highest immediately after a fracture. This study aims to assess if fall risk is time-dependent in subjects with a recent fracture compared to subjects without a fracture.

METHODS

This retrospective matched cohort study used data from the UK Clinical Practice Research Datalink GOLD. All subjects ≥50 years with a fracture between 1993 and 2015 were identified and matched one-to-one to fracture-free controls based on year of birth, sex and practice. The cumulative incidence and relative risk (RR) of a first fall was calculated at various time intervals, with mortality as competing risk. Subsequently, analyses were stratified according to age, sex and type of index fracture.

RESULTS

A total of 624,460 subjects were included; 312,230 subjects with an index fracture, matched to 312,230 fracture-free controls (71% females, mean age 70 ± 12, mean follow-up 6.5 ± 5 years). The RR of falls was highest in the first year after fracture compared to fracture-free controls; males had a 3-fold and females a 2-fold higher risk. This imminent fall risk was present in all age and fracture types and declined over time. A concurrent imminent fracture and mortality risk were confirmed.

CONCLUSION/DISCUSSION

This study demonstrates an imminent fall risk in the first years after a fracture in all age and fracture types. This underlines the need for early fall risk assessment and prevention strategies in 50+ adults with a recent fracture.

Screening and surveillance of venous stenosis in AVG: Is it time to rethink our assumptions?

Guidelines make no firm recommendations about surveillance of arteriovenous grafts as several randomised trials (RCT) have not shown a clear benefit in patency. However a more thorough review of these RCT based on epidemiological principles reveals significant limitations. In particular a key weakness of these older studies is the interventions performed for venous stenosis detected that was largely angioplasty. However, the observational data of modern stent-grafts shows a clear benefit over angioplasty, and thus seems to suggest that a modern well considered RCT is now mandated.

The prognosis of elderly patients with hepatocellular carcinoma after curative hepatectomy a multicenter competing risk analysis

BACKGROUND

Non-cancer-specific death (NCSD) is an important factor that needs to be considered in patients with malignancy, as it can affect their long-term prognosis. In particular, the effect of age on patients with hepatocellular carcinoma (HCC) after hepatectomy requires clarification. This study aims to examine the impact of age on patients with HCC after hepatectomy and to identify independent risk factors of survival.

METHODS

Patients with HCC that fell within the Milan Criteria and had undergone curative hepatectomy were included in this study. The patients were divided into two groups: young patients (age <70) and elderly patients (age ≥70). Perioperative complications, cancer-specific death (CSD), recurrence, and NCSD were all recorded and analyzed. Multivariate analyses were performed to identify independent risk factors of survival using Fine and Gray's competing-risk regression model.

RESULTS

Among 1,354 analytic patients, 1,068 (78.7%) were stratified into the young group and 286 (21.3%) into the elderly group. The elderly group had a higher 5-year cumulative incidence of NCSD (12.6% vs. 3.7% for the young group, P < 0.001), but lower 5-year cumulative incidences of recurrence (20.3% vs. 21.1% for the young group, P = 0.041) and CSD (14.3% vs. 15.5% for the young group, P = 0.066). Multivariate competing-risk regression analyses revealed that age was independently associated with NCSD (subdistribution hazard ratio (SHR) 3.003, 95%CI: 2.082-4.330, P < 0.001), but not with recurrence (SHR 0.837, 95%CI: 0.659-1.060, P = 0.120) or CSD (SHR 0.736, 95%CI: 0.537-1.020, P = 0.158).

CONCLUSION

For patients with early-stage HCC after hepatectomy, older age was independently associated with NCSD, but not recurrence and CSD.

Competing risk models to evaluate the factors for time to loss to follow-up among tuberculosis patients at Ambo General Hospital

BACKGROUND

A major challenge for most tuberculosis programs is the inability of tuberculosis patients to complete treatment for one reason or another. Failure to complete the treatment contributes to the emergence of multidrug-resistant TB. This study aimed to evaluate the risk factors for time to loss to follow-up treatment by considering death as a competing risk event among tuberculosis patients admitted to directly observed treatment short course at Ambo General Hospital, Ambo, Ethiopia.

METHODS

Data collected from 457 tuberculosis patients from January 2018 to January 2022 were used for the analysis. The cause-specific hazard and sub-distribution hazard models for competing risks were used to model the outcome of interest and to identify the prognostic factors associated to treatment loss to follow-up. Loss to follow-up was used as an outcome measure and death as a competing event.

RESULTS

Of the 457 tuberculosis patients enrolled, 54 (11.8%) were loss to follow-up their treatment and 33 (7.2%) died during the follow up period. The median time of loss to follow-up starting from the date of treatment initiation was 4.2 months. The cause-specific hazard and sub-distribution hazard models revealed that sex, place of residence, HIV status, contact history, age and baseline weights of patients were significant risk factors associated with time to loss to follow-up treatment. The findings showed that the estimates of the covariates effects were different for the cause specific and sub-distribution hazard models. The maximum relative difference observed for the covariate between the cause specific and sub-distribution hazard ratios was 12.2%.

CONCLUSIONS

Patients who were male, rural residents, HIV positive, and aged 41 years or older were at higher risk of loss to follow-up their treatment. This underlines the need that tuberculosis patients, especially those in risk categories, be made aware of the length of the directly observed treatment short course and the effects of discontinuing treatment.

Risk of venous thromboembolism and major bleeding in the clinical course of osteosarcoma and Ewing sarcoma

BACKGROUND

Patients with osteosarcoma (OS) and Ewing sarcoma (ES) are considered to have a high venous thromboembolism (VTE) risk, although the exact incidence and prognostic impact are under-researched in general as well as in relevant age groups.

AIMS

To study the impact of VTE and major bleeding (MB) in OS and ES patients, subdivided in children, Adolescents Young Adults (AYAs; aged 18-39) and older adults.

METHODS

Retrospective single-center chart review in 519 OS and 165 ES patients treated between 1980 and 2018. Patients were followed from sarcoma diagnosis until an outcome of interest (VTE, MB) or death occurred. Cumulative incidences were estimated with death as competing risk. Cox models were used to determine prognostic impact.

RESULTS

Five-year cumulative incidences of VTE were 12 % (95%CI 9.1-15) for OS and 6.7 % (95%CI 3.5-11) for ES patients, mostly happening in patients ≥18 years; the most frequent VTE presentation was catheter-related upper-extremity thrombosis (OS: 18/65, ES: 7/11). Five-year cumulative incidences for MB were 5.8 % (95%CI 4.0-8.1) in OS and 5.4 % (95%CI 2.5-9.8) in ES patients. 192 OS and 77 ES AYAs were included, who faced similar VTE and MB incidences as older adults. In OS, VTE and MB were both associated with mortality (adjusted HRs 2.0 [95%CI 1.4-2.9] and 2.4 [95%CI 1.4-4.0], respectively), whereas in ES this association was only present for MB (aHR 3.4 [95%CI 1.2-9.6]).

CONCLUSIONS

VTE is a frequent complication in adult OS and to a lesser extent in ES patients, while the rate of MB was comparably high in both sarcoma types.

Lower revision rates for cemented fixation in a long-term survival analysis of three different LCS designs

BACKGROUND

In primary Total Knee Arthroplasty (TKA), it is still not clear if cemented or uncemented fixation has the best long-term survival. The Low Contact Stress (LCS) mobile-bearing (MB) knee system was introduced in 1977. The aim of this study is to investigate the long-term survival of this design with a minimum of 15-year follow-up.

METHODS

A retrospective analysis was performed, with the primary endpoint for survival defined as revision. Cox regression analysis was performed to assess the association between type of fixation and the risk of revision, while correcting for potential confounders (diagnosis, design, age and sex).

RESULTS

1271 cases were included with inflammatory joint disease (IJD) (657 cases) and non-IJD (614 cases). TKAs were performed cemented in 522 cases and uncemented in 749 cases. A bicruciate retaining design was used in 180 cases, a rotating platform design in 174 cases and an anterior posterior glide posterior cruciate-retaining (PCR) design in 916 cases. Cumulative incidence of component revision at 15 years was 2.7% (95% CI 1.6; 4.5) for cemented and 10% (95% CI 8.1; 12.4) for uncemented TKA, respectively. The 20-year cumulative incidence was 2.9% (95% CI 1.7; 4.7) for cemented and 10.9% (95% CI 8.8; 13.4) for uncemented TKA, respectively. Age, non-IJD and PCR design were associated with a significantly higher risk of revision, regardless of the type of fixation.

CONCLUSION

Long-term survival for patients undergoing cemented or uncemented TKA using the LCS MB system revealed lower revision rates for cemented fixation. Revision risk was higher in younger, non-IJD patients who had the PCR design, regardless of the type of fixation. For the LCS MB TKA design, it is recommended to use cemented fixation.

QUAPAS: An Adaptation of the QUADAS-2 Tool to Assess Prognostic Accuracy Studies

Whereas diagnostic tests help detect the cause of signs and symptoms, prognostic tests assist in evaluating the probable course of the disease and future outcome. Studies to evaluate prognostic tests are longitudinal, which introduces sources of bias different from those for diagnostic accuracy studies. At present, systematic reviews of prognostic tests often use the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool to assess risk of bias and applicability of included studies because no equivalent instrument exists for prognostic accuracy studies. QUAPAS (Quality Assessment of Prognostic Accuracy Studies) is an adaptation of QUADAS-2 for prognostic accuracy studies. Questions likely to identify bias were evaluated in parallel and collated from QUIPS (Quality in Prognosis Studies) and PROBAST (Prediction Model Risk of Bias Assessment Tool) and paired to the corresponding question (or domain) in QUADAS-2. A steering group conducted and reviewed 3 rounds of modifications before arriving at the final set of domains and signaling questions. QUAPAS follows the same steps as QUADAS-2: Specify the review question, tailor the tool, draw a flow diagram, judge risk of bias, and identify applicability concerns. Risk of bias is judged across the following 5 domains: participants, index test, outcome, flow and timing, and analysis. Signaling questions assist the final judgment for each domain. Applicability concerns are assessed for the first 4 domains. The authors used QUAPAS in parallel with QUADAS-2 and QUIPS in a systematic review of prognostic accuracy studies. QUAPAS improved the assessment of the flow and timing domain and flagged a study at risk of bias in the new analysis domain. Judgment of risk of bias in the analysis domain was challenging because of sparse reporting of statistical methods.

Risk of Arterial Thromboembolism, Venous Thromboembolism, and Bleeding in Patients with Nephrotic Syndrome: A Population-Based Cohort Study

BACKGROUND

Although venous thromboembolism is a well-known complication of nephrotic syndrome, the long-term absolute and relative risks of arterial thromboembolism, venous thromboembolism, and bleeding in adults with nephrotic syndrome remain unclarified.

METHODS

In this matched cohort study, we identified every adult with first-time recorded nephrotic syndrome from admissions, outpatient clinics, or emergency department visits in Denmark during 1995-2018. Each patient was matched by age and sex with 10 individuals from the general population. We estimated the 10-year cumulative risks of recorded arterial thromboembolism, venous thromboembolism, and bleeding accounting for the competing risk of death. Using Cox models, we computed crude and adjusted hazard ratios (HRs) of the outcomes in patients with nephrotic syndrome versus comparators.

RESULTS

Among 3967 adults with first-time nephrotic syndrome, the 1-year risk of arterial thromboembolism was 4.2% (95% confidence interval [CI] 3.6-4.8), of venous thromboembolism was 2.8% (95% CI 2.3-3.3), and of bleeding was 5.2% (95% CI 4.5-5.9). The 10-year risk of arterial thromboembolism was 14.0% (95% CI 12.8-15.2), of venous thromboembolism 7.7% (95% CI 6.8-8.6), and of bleeding 17.0% (95% CI 15.7-18.3), with highest risks of ischemic stroke (8.1%), myocardial infarction (6.0%), and gastrointestinal bleeding (8.2%). During the first year, patients with nephrotic syndrome had increased rates of both arterial thromboembolism (adjusted HR [HR_adj] = 3.11 [95% CI 2.60-3.73]), venous thromboembolism (HR_adj = 7.11 [5.49-9.19]), and bleeding (HR_adj = 4.02 [3.40-4.75]) compared with the general population comparators after adjusting for confounders.

CONCLUSION

Adults with nephrotic syndrome have a high risk of arterial thromboembolism, venous thromboembolism, and bleeding compared with the general population. The mechanisms and consequences of this needs to be clarified.

The long-term prognosis of patients with untreated primary uveal melanoma: A systematic review and meta-analysis

PURPOSE

To examine patient survival in untreated primary uveal melanoma.

METHODS

Systematic review and meta-analysis.

RESULTS

Seven studies with a total of 19 patients were included. Fifteen patients died from metastases during a median follow-up of > 20 years. When excluding two patients with iris melanoma, fifteen of 17 patients with choroidal or ciliary body melanoma developed metastases. The cumulative disease-specific survival for these 17 patients was 71% at five years, 29% at 10 years, 18% at 15 years and 11% at 30 years. This was significantly worse than the survival in comparison cohorts of both medium-sized and large treated tumors (p < 0.001).

CONCLUSIONS

Among the exceedingly rare published patients with untreated primary uveal melanoma, 80-90% have developed metastases and their disease-specific survival seems to be shorter than treated patients. This could indicate that some metastases might be prevented by primary tumor treatment.

Long-term relative survival in uveal melanoma: a systematic review and meta-analysis

Background

A large proportion of patients with uveal melanoma develop metastases and succumb to their disease. Reports on the size of this proportion vary considerably.

Methods

PubMed, Web of Science and Embase were searched for articles published after 1980. Studies with ≥100 patients reporting ≥five-year relative survival rates were included. Studies solely reporting Kaplan-Meier estimates and cumulative incidences were not considered, due to risk for competing risk bias and classification errors. A meta-analysis was performed using random-effects and weighted averages models, as well as a combined estimate based on curve fitting.

Results

Nine studies and a total of 18 495 patients are included. Overall, the risk of selective reporting bias is low. Relative survival rates vary across the population of studies (I2 48 to 97% and Qp < 0.00001 to 0.15), likely due to differences in baseline characteristics and the large number of patients included (τ2 < 0.02). The 30-year relative survival rates follow a cubic curve that is well fitted to data from the random-effects inverse-variance and weighted average models (R2 = 0.95, p = 7.19E−7). The estimated five, ten, 15, 20, 25 and 30-year relative survival rates are 79, 66, 60, 60, 62 and 67%, respectively.

Conclusions

The findings suggest that about two in five of all patients with uveal melanoma ultimately succumb to their disease. This indicates a slightly better prognosis than what is often assumed, and that patients surviving 20 years or longer may have a survival advantage to individuals of the same sex and age from the general population.

Switching from vitamin K antagonists to direct oral anticoagulants in non-valvular atrial fibrillation patients: Does low time in therapeutic range affect persistence?

BACKGROUND

Non-valvular atrial fibrillation (NVAF) patients are advised to switch from a vitamin K antagonist (VKA) to direct oral anticoagulant (DOAC) when time in therapeutic range (TTR) is low.

OBJECTIVE

To examine if pre-switch TTR determines persistence patterns in NVAF patients who are switched from a VKA to DOAC.

PATIENTS/METHODS

Adult NVAF patients from three Dutch anticoagulation clinics who were newly switched from a VKA to DOAC between July 1, 2013 and September 30, 2018 were stratified by pre-switch TTR levels. DOAC prescription records were examined to determine persistence patterns according to a 100-day prescription gap. Cumulative incidences of non-persistence to DOAC were estimated using the cumulative incidence competing risk method. The association of pre-switch TTR levels with DOAC non-persistence was evaluated by Cox regression models.

RESULTS

A total of 3696 NVAF patients were included, of whom 690 (18.7%) had a pre-switch TTR ≤ 45%. After switching from VKA to DOAC, 14.0% (95% confidence interval [CI] 11.3-17.0%) of the patients with a pre-switch TTR ≤ 45% became non-persistent to DOAC within 1 year, while 9.8% (95% CI 8.7-11.0%) did in those with a pre-switch TTR > 45%. In a multivariable model, a pre-switch TTR ≤ 45% was associated with a higher risk of non-persistence to DOAC (adjusted hazard ratio 1.55, 95% CI 1.22-1.97). Results were similar when using other cut-off points (60% or 70%) to define a low TTR.

CONCLUSION

NVAF patients switching from VKA to DOAC due to a low pre-switch TTR saw a worse persistence pattern to DOAC after the switch compared to patients with a high pre-switch TTR.

Death With Function and Graft Failure After Kidney Transplantation: Risk Factors at Baseline Suggest New Approaches to Management

Background

Improving both patient and graft survival after kidney transplantation are major unmet needs. The goal of this study was to assess risk factors for specific causes of graft loss to determine to what extent patients who develop either death with a functioning graft (DWFG) or graft failure (GF) have similar baseline risk factors for graft loss.

Methods

We retrospectively studied all solitary renal transplants performed between January 1, 2006, and December 31, 2018, at 3 centers and determined the specific causes of DWFG and GF. We examined outcomes in different subgroups using competing risk estimates and cause-specific Cox models.

Results

Of the 5752 kidney transplants, graft loss occurred in 21.6% (1244) patients, including 12.0% (691) DWFG and 9.6% (553) GF. DWFG was most commonly due to malignancy (20.0%), infection (19.7%), cardiac disease (12.6%) with risk factors of older age and pretransplant dialysis, and diabetes as the cause of renal failure. For GF, alloimmunity (38.7%), glomerular diseases (18.6%), and tubular injury (13.9%) were the major causes. Competing risk incidence models identified diabetes and older recipients with higher rates of both DWFG and nonalloimmune GF.

Conclusions

These data suggest that at baseline, 2 distinct populations can be identified who are at high risk for renal allograft loss: a younger, nondiabetic patient group who develops GF due to alloimmunity and an older, more commonly diabetic population who develops DWFG and GF due to a mixture of causes-many nonalloimmune. Individualized management is needed to improve long-term renal allograft survival in the latter group.

Lessons learnt when accounting for competing events in the external validation of time-to-event prognostic models

Background

External validation of prognostic models is necessary to assess the accuracy and generalizability of the model to new patients. If models are validated in a setting in which competing events occur, these competing risks should be accounted for when comparing predicted risks to observed outcomes.

Methods

We discuss existing measures of calibration and discrimination that incorporate competing events for time-to-event models. These methods are illustrated using a clinical-data example concerning the prediction of kidney failure in a population with advanced chronic kidney disease (CKD), using the guideline-recommended Kidney Failure Risk Equation (KFRE). The KFRE was developed using Cox regression in a diverse population of CKD patients and has been proposed for use in patients with advanced CKD in whom death is a frequent competing event.

Results

When validating the 5-year KFRE with methods that account for competing events, it becomes apparent that the 5-year KFRE considerably overestimates the real-world risk of kidney failure. The absolute overestimation was 10%age points on average and 29%age points in older high-risk patients.

Conclusions

It is crucial that competing events are accounted for during external validation to provide a more reliable assessment the performance of a model in clinical settings in which competing risks occur.

Competing Risk Analysis in Renal Allograft Survival: A New Perspective to an Old Problem

BACKGROUND

Graft survival after kidney transplant (KTX) is often estimated by the Kaplan-Meier (KM) method censoring for competing endpoints, primarily death. This method overestimates the incidence of graft loss.

METHODS

In 3157 adult KTX recipients followed for a mean of 79.2 months, we compared kidney and patient survival probabilities by KM versus competing risk analysis (CRA). These methods are extended to comparing different regression methods.

RESULTS

Compared with CRA, the probabilities of death and graft loss (censored for the other outcome) were substantially higher by KM. These differences increased with increasing follow-up time. Importantly, differences in graft losses were magnified in subgroups with greater probabilities of death. Among recipients with diabetes, the probabilities of graft loss at 20 years were 57% by KM and 32% by CRA, while for non-diabetes mellitus corresponding values were 44% and 35%. Similar results are noted when comparing older versus younger recipients. Finally, we find that the Fine-Gray method assumptions are violated when using age and gender as covariates and that the alternative method of Aalen-Johansen may be more appropriate.

CONCLUSIONS

CRA provides more accurate estimates of long-term graft survival and death, particularly in subgroups of recipients with higher rates of the competing event. Overestimation of risk by KM leads to both quantitative and qualitative misinterpretations of long-term KTX outcomes. When using regression analyses, care should be taken to check assumptions to guide the choice of appropriate method.

Design and rationale of the ATtune Knee Outcome Study (ATKOS): multicenter prospective evaluation of a novel uncemented rotating platform knee system

Background

Total Knee Arthroplasty (TKA) remains the gold standard for treatment of debilitating symptoms of knee osteoarthritis (OA). Even though providing satisfactory results for the majority of patients, some studies report dissatisfaction after TKA to be as high as 20%. Among other things, pain catastrophising and self-efficacy are thought to compromise results of TKA. Implant manufacturers keep improving upon their designs in an attempt to improve functional outcomes. One of these novel knee systems is the Attune. To our knowledge, there are no clinical follow-up studies reporting results of the uncemented version. The main objective of this multicentre prospective observational study is to evaluate revision rate, complications, radiographic outcomes (i.e. alignment and radiolucent lines) and patient reported outcomes of the uncemented Attune mobile bearing TKA. Secondary objectives are (1) to assess physical function, return to sport and return to work after TKA and (2) to evaluate the long-term effect of preoperative psychological factors on satisfaction after TKA.

Methods

All patients presenting in the participating centres with knee pathology warranting joint replacement therapy will be considered for inclusion, an absolute indication for cemented fixation is the only exclusion criterium. Evaluation of clinical and radiographic performance (e.g. radiolucent lines) is done at 6 weeks, 6 months, 1 year, 5 years and 10 years after surgery using validated patient reported outcome measures. Cumulative revision rates are calculated after 5 and 10 years using Kaplan–Meier methods. Physical function is assessed with performance based measurements before and 1 year after surgery. Return to sports is assessed using the Tegner and University of California Los Angeles (UCLA) activity rating scale before and 1 year after surgery. Return to work is evaluated by inviting patients of working age to complete a short questionnaire 1 year after surgery. Psychologic factors are assessed using questionnaires for pain catastrophising, pain self-efficacy and mental health before, 5 years and 10 years after surgery. Preoperative psychologic scores are correlated to functional outcomes.

Discussion

The current study aims to report the clinical performance of a novel implant and can help provide insight in factors that play a role in satisfaction after TKA.

Trial registration

ClinicalTrials.gov identifier: NCT04247672 (January 30, 2020)

Risk of revision for medial unicompartmental knee arthroplasty according to fixation and bearing type : short- to mid-term results from the Dutch Arthroplasty Register

AIMS

Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs.

METHODS

A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed.

RESULTS

In hospitals performing less than 100 cases per year, cemented mobile bearings reported comparable adjusted risks of revision as uncemented mobile bearings. However, in hospitals performing more than 100 cases per year, the adjusted risk of revision was higher for cemented mobile bearings compared to uncemented mobile bearings (hazard ratio 1.78 (95% confidence interval 1.34 to 2.35)). The adjusted risk of revision between cemented fixed bearing and uncemented mobile bearing was comparable, independent of annual hospital volume. In addition, 12.3% of uncemented mobile bearing, 20.3% of cemented mobile bearing, and 41.5% of uncemented fixed bearing revisions were for tibial component loosening. The figures for instability were 23.6%, 14.5% and 11.7%, respectively, and for periprosthetic fractures were 10.0%, 2.8%, and 3.5%. Bearing exchange was the type of revision in 40% of uncemented mobile bearing, 24.3% of cemented mobile bearing, and 5.3% cemented fixed bearing revisions.

CONCLUSION

The findings of this study demonstrated improved survival with use of uncemented compared to cemented mobile bearings in medial UKA, only in those hospitals performing more than 100 cases per year. Cemented fixed bearings reported comparable survival results as uncemented mobile bearings, regardless of the annual hospital volume. The high rates of instability, periprosthetic fractures, and bearing exchange in uncemented mobile bearings emphasize the need for further research. Cite this article: Bone Joint J 2021;103-B(7):1261-1269.

Cardiovascular events in patients with chronic myeloid leukaemia treated with tyrosine kinase inhibitors in Taiwan: a nationwide population-based study

AIMS

New-generation breakpoint cluster region-Abelson tyrosine kinase inhibitors (TKIs) have a higher incidence of cardiovascular events than imatinib in patients with chronic myeloid leukaemia (CML). However, this knowledge is insufficiently proven. Hence, this study aimed to explore the association between cardiovascular events and TKIs in patients with CML.

METHODS AND RESULTS

This retrospective population-based cohort study enrolled first-time users of imatinib, dasatinib, and nilotinib between 1 January 2007 and 31 December 2016. Arterial thromboembolic events (ATEs) were the primary outcome, while other cardiovascular-related events were the secondary outcomes. The event rates were estimated using Kaplan-Meier estimates, and the hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression. Additionally, the competing risk was adjusted using the Fine and Gray competing risk model. We included 1207 patients. Nilotinib had a significantly higher ATE risk (subdistribution HR = 4.92, 95% CI = 1.68-14.36) than imatinib. Conversely, no difference was found for other cardiovascular-related events. Risks of ATE and other cardiovascular-related events were similar between dasatinib and imatinib and between nilotinib and dasatinib. The risk of ATE hospitalization consistently increased throughout the main analyses and sensitivity analyses.

CONCLUSION

Nilotinib-treated patients had a significantly higher risk of developing ATE than imatinib-treated patients. However, the risks of ATE and other cardiovascular-related events were not significantly different between dasatinib and imatinib.

Nomograms for Estimating Cause-Specific Death Rates of Patients With Inflammatory Breast Cancer: A Competing-Risks Analysis

Purpose:

Inflammatory breast cancer (IBC) is a rare, aggressive and special subtype of primary breast cancer. We aimed to establish competing-risks nomograms to predict the IBC-specific death (BCSD) and other-cause-specific death (OCSD) of IBC patients.

Methods:

We extracted data on primary IBC patients from the SEER (Surveillance, Epidemiology, and End Results) database by applying specific inclusion and exclusion criteria. Cumulative incidence function (CIF) was used to calculate the cumulative incidence rates and Gray’s test was used to evaluate the difference between groups. Fine-Gray proportional subdistribution hazard method was applied to identify the independent predictors. We then established nomograms to predict the 1-, 3-, and 5-year cumulative incidence rates of BCSD and OCSD based on the results. The calibration curves and concordance index (C-index) were adopted to validate the nomograms.

Results:

We enrolled 1699 eligible IBC patients eventually. In general, the 1-, 3-, and 5-years cumulative incidence rates of BCSD were 15.3%, 41.0%, and 50.7%, respectively, while those of OCSD were 3.0%, 5.1%, and 7.4%. The following 9 variables were independent predictive factors for BCSD: race, lymph node ratio (LNR), AJCC M stage, histological grade, ER (estrogen receptor) status, PR (progesterone receptor) status, HER-2 (human epidermal growth factor-like receptor 2) status, surgery status, and radiotherapy status. Meanwhile, age, ER, PR and chemotherapy status could predict OCSD independently. These factors were integrated for the construction of the competing-risks nomograms. The results of calibration curves and C-indexes indicated the nomograms had good performance.

Conclusions:

Based on the SEER database, we established the first competing-risks nomograms to predict BCSD and OCSD of IBC patients. The good performance indicated that they could be incorporated in clinical practice to provide references for clinicians to make individualized treatment strategies.

Long-term mortality among kidney transplant recipients with and without diabetes: a nationwide cohort study in the USA

INTRODUCTION

Little is known about the role diabetes (type 1 (T1D) and type 2 (T2D)) plays in modifying prognosis among kidney transplant recipients. Here, we compare mortality among transplant recipients with T1D, T2D and non-diabetes-related end-stage kidney disease (ESKD).

RESEARCH DESIGN AND METHODS

We included 254 188 first-time single kidney transplant recipients aged ≥18 years from the US Renal Data System (2000-2018). Diabetes status, as primary cause of ESKD, was defined using International Classification of Disease 9th and 10th Clinical Modification codes. Multivariable-adjusted Cox regression models (right-censored) computed risk of death associated with T1D and T2D relative to non-diabetes. Trends in standardized mortality ratios (SMRs) (2000-2017), relative to the general US population, were assessed using Joinpoint regression.

RESULTS

A total of 72 175 (28.4%) deaths occurred over a median survival time of 14.6 years. 5-year survival probabilities were 88%, 85% and 77% for non-diabetes, T1D and T2D, respectively. In adjusted models, mortality was highest for T1D (HR=1.95, (95% CI: 1.88 to 2.03)) and then T2D (1.65 (1.62 to 1.69)), as compared with non-diabetes. SMRs declined for non-diabetes, T1D, and T2D. However, in 2017, SMRs were 2.38 (2.31 to 2.45), 6.55 (6.07 to 7.06), and 3.82 (3.68 to 3.98), for non-diabetes, T1D and T2D, respectively.

CONCLUSIONS

In the USA, diabetes type is an important modifier in mortality risk among kidney transplant recipients with highest rates among people with T1D-related ESKD. Development of effective interventions that reduce excess mortality in transplant recipients with diabetes is needed, especially for T1D.

Competing-Risk Nomograms for Predicting the Prognosis of Patients With Infiltrating Lobular Carcinoma of the Breast

BACKGROUND

Infiltrating lobular carcinoma (ILC) is the second most common histologic subtype of breast cancer. We assessed the rates of cause-specific death in ILC patients with the aim of establishing competing-risk nomograms for predicting their prognosis.

PATIENTS AND METHODS

Data on ILC patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence function was used to calculate the cumulative incidence rates of cause-specific death, and Gray's test was applied to test the differences in cumulative incidence rates among groups. We then identified independent prognostic factors by applying the Fine-Gray proportional subdistribution hazard analysis method and established nomograms based on the results. Calibration curves and the concordance index were employed to validate the nomograms.

RESULTS

The study enrolled 11,361 patients. The 3-, 5-, and 10-year overall cumulative incidence rates for those who died of ILC were 3.1%, 6.2%, and 12.2%, respectively, whereas the rates for those who died from other causes were 3.2%, 5.8%, and 14.1%. Age, marriage, grade, size, regional node positivity, American Joint Committee on Cancer M stage, progesterone receptor, and surgery were independent prognostic factors for dying of ILC, whereas the independent prognostic factors for dying of other causes were age, race, marriage, size, radiation, and chemotherapy. The nomograms were well calibrated and had good discrimination ability.

CONCLUSION

We applied competing-risk analysis to ILC patients based on the SEER database and established nomograms that perform well in predicting the cause-specific death rates at 3, 5, and 10 years after the diagnosis.

Impact of dialysis modality on morbimortality of kidney transplant recipients after allograft failure. Analysis in the presence of competing events

BACKGROUND AND OBJECTIVE

The number of patients who start dialysis due to graft failure increases every day. The best dialysis modality for this type of patient is not well defined and most patients are referred to HD. The objective of our study is to evaluate the impact of the dialysis modality on morbidity and mortality in transplant patients who start dialysis after graft failure.

MATERIAL AND METHODS

A multicentre retrospective observation and cohort study was performed to compare the evolution of patients who started dialysis after graft failure from January 2000 to December 2013. One group started on PD and the other on HD. The patients were followed until the change of dialysis technique, retransplantation or death. Anthropometric data, comorbidity, estimated glomerular filtration rate (eGFR) at start of dialysis, the presence of an optimal access for dialysis, the appearance of graft intolerance and retransplantation were analyzed. We studied the causes for the first 10 hospital admissions after starting dialysis. For the statistical analysis, the presence of competitive events that hindered the observation of the event of interest, death or hospital admission was analyzed.

RESULTS

175 patients were included, 86 in DP and 89 in HD. The patients who started PD were younger, had less comorbidity and started dialysis with lower eGFR than those on HD. The mean follow-up was 34 ± 33 months, with a median of 24 months (IQR 7-50 months), Patients on HD had longer follow-up than patients on PD (35 vs. 18 months, p = < 0.001). The mortality risk factors were age sHR 1.06 (95% CI: 1.03-1.106, p = 0.000), non-optimal use of access for dialysis sHR 3.00 (95% CI: 1.507-5.982, p = 0.028) and the dialysis modality sHR (PD/HD) 0.36 (95% CI: 0.148-0.890, p = 0.028). Patients on PD had a lower risk of hospital admission sHR [DP/HD] 0.52 (95% CI: 0.369-0.743, p = < 0.001) and less probability of developing graft intolerance HR 0.307 (95% CI 0.142-0.758, p = 0.009).

CONCLUSIONS

With the limitations of a retrospective and non-randomized study, it is the first time nationwide that PD shows in terms of survival to be better than HD during the first year and a half after the kidney graft failure. The presence of a non-optimal access for dialysis was an independent and modifiable risk factor for mortality. Early referral of patients to advanced chronic kidney disease units is essential for the patient to choose the technique that best suits their circumstances and to prepare an optimal access for the start of dialysis.

Survival analysis-part 3: intermediate events and the importance of competing risks

LEARNING OBJECTIVES

Understand what events can be labelled as intermediate events in survival analysis.Understand why the Kaplan and Meier method cannot be used in the presence of competing events.Regression analysis in the presence of competing events.

Incidence and mortality of new-onset glucose disorders in peritoneal dialysis patients in China: a meta-analysis

Background

Dialysis patients are at high risk of developing glucose metabolism disturbances (GMDs), such as diabetes mellitus (DM), impaired fast glucose (IFG), and impaired glucose tolerance (IGT). However, it is unclear about the incidence of GMDs in Chinese patients with peritoneal dialysis (PD), as well as the influence of new-onset DM (NODM) on the prognosis of PD patients. Therefore, we conducted this meta-analysis to address these issues.

Methods

A comprehensive literature search was conducted using PubMed, Embase, Web of Science, SinoMed, and CNKI database for studies that evaluated the incidence of GMDs and mortality in patients with PD. Results were expressed as hazard ratio (HR), risk ratio (RR), or estimate (ES) with 95% confidence intervals (95%CIs).Meta-analysis was performed using a fixed-effects or random-effects model to pool the estimate.

Results

Fifteen studies met the inclusion criteria and were included in this meta-analysis. Pooled results showed that, the incidences of NODM, NOIGT, and NOIFG were 12% (95%CI: 9, 15%; P < 0.001), 17% (95%CI: 4, 10%; P < 0.001) and 32% (95%CI: 3, 30%, P < 0.001), respectively. Compared with patients without NODM, PD patients with NODM had an increased risk of mortality (HR = 1.59, 95%CI: 1.28, 1.98; P < 0.001). There was no significant difference in the incidence of NODM between PD and hemodialysis (HD) patients (RR = 1.23, 95%CI: 0.61, 2.51; P = 0.562).

Conclusion

Dialysis patients in China had an increased risk of developing GMDs, however, the dialysis modality did not have any significant impact on the incidence of NODM. NODM increased the mortality risk in patients undergoing PD. Thus, physicians should pay attention to the plasma glucose level in patients undergoing dialysis.

Clinical outcomes of prolonged dual antiplatelet therapy after coronary drug-eluting stent implantation in dialysis patients

Background

End-stage renal disease yields susceptibility to both ischemia and bleeding. The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation is not established in dialysis patients, who are usually excluded from randomized studies. Since recent studies implied the benefits of prolonged DAPT >12 months in chronic kidney disease, we investigated the effectiveness and safety of prolonged DAPT in dialysis patients with higher cardiovascular risks.

Methods

In this nationwide population-based study, we analyzed dialysis patients who underwent DES implantation from 2008 to 2015. Continued DAPT was compared with discontinued DAPT using landmark analyses, including free-of-event participants at 12 (n = 2246), 15 (n = 1925) and 18 months (n = 1692) after DES implantation. The primary outcome was major adverse cardiovascular events (MACEs): a composite of mortality, nonfatal myocardial infarction, coronary revascularization and stroke. Major bleeding was a safety outcome. Inverse probability of treatment weighting Cox regression was performed.

Results

Mean follow-up periods were 278.3-292.4 days, depending on landmarks. Overall, incidences of major bleeding were far lower than those of MACE. Continued DAPT groups showed lower incidences of MACE and higher incidences of major bleeding, compared with discontinued DAPT groups. In Cox analyses, continued DAPT reduced the hazards of MACE at the 12- [hazard ratio (HR) = 0.74, 95% confidence interval (CI) 0.61-0.90; P = 0.003], 15- (HR = 0.78, 95% CI 0.64-0.96; P = 0.019) and 18-month landmarks (HR = 0.79, 95% CI 0.63-0.99; P = 0.041), but without a significant increase in major bleeding at 12 (HR = 1.39, 95% CI 0.90-2.16; P = 0.14), 15 (HR = 1.13, 95% CI 0.75-1.70; P = 0.55) or 18 months (HR = 1.27, 95% CI 0.83-1.95; P = 0.27).

Conclusions

Prolonged DAPT reduced MACE without significantly increasing major bleeding in patients who were event-free at 12 months after DES implantation. In deciding on DAPT duration, prolonged DAPT should be considered in dialysis patients.

Investigation of the relationship between sensorineural hearing loss and associated comorbidities in patients with chronic kidney disease: A nationwide, population-based cohort study

Hearing impairment was observed in patients with chronic kidney disease (CKD). Our purpose was to investigate the relationship between sensorineural hearing loss (SNHL) and associated comorbidities in the CKD population. We conducted a retrospective, population-based study to examine the risk of developing SNHL in patients with CKD. Population-based data from 2000–2010 from the Longitudinal Health Insurance Database of the Taiwan National Health Insurance Research Database was used in this study. The population sample comprised 185,430 patients who were diagnosed with CKD, and 556,290 without CKD to determine SNHL risk factors. Cox proportional hazard regression analysis demonstrated the CKD group had a significantly increased risk of SNHL compared with the non-CKD group [adjusted hazard ratio (HR), 3.42; 95% confidence interval (CI), 3.01–3.90, p < 0.001]. In the CKD group, the risk of SNHL (adjusted HR, 5.92) was higher among patients undergoing hemodialysis than among those not undergoing hemodialysis (adjusted HR, 1.40). Furthermore, subgroup analysis revealed an increased risk of SNHL in patients with CKD and comorbidities, including heart failure (adjusted HR, 7.48), liver cirrhosis (adjusted HR, 4.12), type 2 diabetes mellitus (adjusted HR, 3.98), hypertension (adjusted HR, 3.67), and chronic obstructive pulmonary disease (adjusted HR, 3.45). CKD is an independent risk of developing SNHL. Additionally, hemodialysis for uremia can increase the risk of SNHL. Cardiovascular, lung, liver, and metabolic comorbidities in CKD patients may further aggravate the risk of SNHL by inter-organ crosstalk. We should pay attention to SNHL in this high-risk population.

Modeling Personalized Adjuvant TreaTment in EaRly stage coloN cancer (PATTERN)

AIM

To develop a decision model for the population-level evaluation of strategies to improve the selection of stage II colon cancer (CC) patients who benefit from adjuvant chemotherapy.

METHODS

A Markov cohort model with a one-month cycle length and a lifelong time horizon was developed. Five health states were included; diagnosis, 90-day mortality, death other causes, recurrence and CC death. Data from the Netherlands Cancer Registry were used to parameterize the model. Transition probabilities were estimated using parametric survival models including relevant clinical and pathological covariates. Subsequently, biomarker status was implemented using external data. Treatment effect was incorporated using pooled trial data. Model development, data sources used, parameter estimation, and internal and external validation are described in detail. To illustrate the use of the model, three example strategies were evaluated in which allocation of treatment was based on (A) 100% adherence to the Dutch guidelines, (B) observed adherence to guideline recommendations and (C) a biomarker-driven strategy.

RESULTS

Overall, the model showed good internal and external validity. Age, tumor growth, tumor sidedness, evaluated lymph nodes, and biomarker status were included as covariates. For the example strategies, the model predicted 83, 87 and 77 CC deaths after 5 years in a cohort of 1000 patients for strategies A, B and C, respectively.

CONCLUSION

This model can be used to evaluate strategies for the allocation of adjuvant chemotherapy in stage II CC patients. In future studies, the model will be used to estimate population-level long-term health gain and cost-effectiveness of biomarker-based selection strategies.

Real-world on-treatment and initial treatment absolute risk differences for dabigatran vs warfarin in older US adults

PURPOSE

Trials and past observational work compared dabigatran and warfarin in patients with atrial fibrillation, but few reported estimates of absolute harm and benefit under real-world adherence patterns, particularly in older adults that may have differing benefit-harm profiles. We aimed to estimate risk differences for ischemic stroke, death, and gastrointestinal bleeding after initiating dabigatran and warfarin in older adults (a) when patients adhere to treatment and (b) under real-world adherence patterns.

METHODS

In a 20% sample of nationwide Medicare claims from 2010 to 2015, we identified beneficiaries aged 66 years and older initiating warfarin and dabigatran. We followed individuals from initiation until death or October 2015 (initial treatment, IT) and separately censored individuals' follow-up after drug switches and gaps in supply (on-treatment, OT). We applied inverse probability of treatment and standardized morbidity ratio weights, as well as inverse probability of censoring weights, to estimate two-year risk differences (RDs) for dabigatran vs warfarin.

RESULTS

We identified 10,717 dabigatran and 74,891 warfarin initiators. Weighted OT RDs suggested decreased ischemic stroke risk for dabigatran vs warfarin; IT RDs indicated increased or no change in ischemic stroke risk. Regardless of follow-up approach and weighting strategy, risk of death appeared lower and risk of gastrointestinal bleeding appeared higher when comparing dabigatran vs warfarin.

CONCLUSIONS

Dabigatran use was associated with lower risks of mortality and ischemic stroke in routine care when older adults stayed on treatment. IT analyses suggested that these benefits may be diminished under real-world patterns of switching and discontinuation.

Ignoring competing events in the analysis of survival data may lead to biased results: a nonmathematical illustration of competing risk analysis

OBJECTIVE

Competing events are often ignored in epidemiological studies. Conventional methods for the analysis of survival data assume independent or noninformative censoring, which is violated when subjects that experience a competing event are censored. Because many survival studies do not apply competing risk analysis, we explain and illustrate in a nonmathematical way how to analyze and interpret survival data in the presence of competing events.

STUDY DESIGN AND SETTING

Using data from the Longitudinal Aging Study Amsterdam, both marginal analyses (Kaplan-Meier method and Cox proportional-hazards regression) and competing risk analyses (cumulative incidence function [CIF], cause-specific and subdistribution hazard regression) were performed. We analyzed the association between sex and depressive symptoms, in which death before the onset of depression was a competing event.

RESULTS

The Kaplan-Meier method overestimated the cumulative incidence of depressive symptoms. Instead, the CIF should be used. As the subdistribution hazard model has a one-to-one relation with the CIF, it is recommended for prediction research, whereas the cause-specific hazard model is recommended for etiologic research.

CONCLUSION

When competing risks are present, the type of research question guides the choice of the analytical model to be used. In any case, results should be presented for all event types.

Outcome prediction in disorders of consciousness: the role of coma recovery scale revised

Background

To evaluate the utility of the revised coma remission scale (CRS-r), together with other clinical variables, in predicting emergence from disorders of consciousness (DoC) during intensive rehabilitation care.

Methods

Data were retrospectively extracted from the medical records of patients enrolled in a specialized intensive rehabilitation unit. 123 patients in a vegetative state (VS) and 57 in a minimally conscious state (MCS) were included and followed for a period of 8 weeks. Demographical and clinical factors were used as outcome measures. Univariate and multivariate Cox regression models were employed for examining potential predictors for clinical outcome along the time.

Results

VS and MCS groups were matched for demographical and clinical variables (i.e., age, aetiology, tracheostomy and route of feeding). Within 2 months after admission in intensive neurorehabilitation unit, 3.9% were dead, 35.5% had a full recovery of consciousness and 66.7% remained in VS or MCS. Multivariate analysis demonstrated that the best predictor of functional improvement was the CRS-r scores. In particular, patients with values greater than 12 at admission were those with a favourable likelihood of emergence from DoC.

Conclusions

Our study highlights the role of the CRS-r scores for predicting a short-term favorable outcome.

Liver Transplant Waitlist Outcomes and the Allocation of Hepatocellular Carcinoma Model for End-Stage Liver Disease Exception Points at a Low-Volume Center

BACKGROUND

Organ scarcity continues to be the main problem limiting the number of liver transplants performed. Outcomes of patients waitlisted for an organ in an Asian country with low organ donation rate have not been well evaluated. Our current policy of allocating 15 exception points to patients with hepatocellular carcinoma (HCC) to render them competitive for a transplant also requires review.

METHODS

The waiting list registry and the organ transplant registry of a single institution in Asia were reviewed from December 2005 to June 2016 for all patients who underwent liver transplantation. Patient characteristics and outcomes of waitlist dropouts were evaluated. Statistical analyses were performed using SPSS version 20.0.

RESULTS

One hundred seventy-three patients were waitlisted for a deceased donor liver-only transplant. The most common etiology of liver disease was hepatitis B, followed by cholestatic diseases. Approximately half of the patients had HCC (45.6%). Priority listing for transplant comprised 15.6% of cases. Median Model for End-Stage Liver Disease (MELD) at listing was 15, and median waiting time to transplant was 17 weeks (interquartile range = 6.5-43.5). Overall, 89 (51.4%) patients underwent liver transplantation and 68 (39.3%) dropped out. For patients with HCC, the most common cause of dropout was progression beyond University of California San Francisco transplant criteria (62.5%). The cumulative incidence of dropout at 3 months among patients with HCC who received exception MELD scores was 11%. This was higher than those listed with physiologic MELD of 14-16 points (7%) but lower than those with 17-19 points (16%).

CONCLUSIONS

Hepatitis B-related liver disease and HCC comprise the majority of patients listed for liver transplant. Dropout rates are high and this is due to the lack of donor organs. The current policy of allocating 15 exception MELD points to patients with HCC within transplant criteria may underestimate the dropout risk of patients with HCC in our population.

Association of Long-term Outcomes and Survival With Multidisciplinary Salvage Treatment for Local and Regional Recurrence After Stereotactic Ablative Radiotherapy for Early-Stage Lung Cancer

Importance

Stereotactic ablative radiotherapy (SABR) is first-line treatment for patients with early-stage non-small cell lung cancer (NSCLC) who cannot undergo surgery. However, up to 1 in 6 such patients will develop isolated local recurrence (iLR) or isolated regional recurrence (iRR). Little is known about outcomes when disease recurs after SABR, or about optimal management strategies for such recurrences.

Objective

To characterize long-term outcomes for patients with iLR or iRR after SABR for early-stage NSCLC with the aim of informing treatment decision making for these patients with potentially curable disease.

Design, Setting, and Participants

In this cohort study, a retrospective review was conducted of 912 patients prospectively enrolled in an institutional database at a tertiary cancer center from January 1, 2004, through December 31, 2014.

Main Outcomes and Measures

Overall survival, progression-free survival, recurrence patterns, demographics, salvage techniques, patterns of salvage failure, and toxic effects.

Results

Of the 912 patients in the study (456 women and 456 men; median age, 72 years [range, 46-91 years]), 756 (82.9%) had T1 tumors at initial diagnosis; 502 tumors (55.0%) were adenocarcinomas and 309 tumors (33.9%) were squamous cell carcinomas. Of 912 patients with early-stage I to II NSCLC who received definitive SABR (50 Gy in 4 fractions or 70 Gy in 10 fractions), 102 developed isolated recurrence (49 with iLR and 53 with iRR), and 658 had no recurrence. Median times to recurrence after SABR were 14.5 months (range, 1.5-60.8 months) for iLR and 9.0 months (range, 1.9-70.7 months) for iRR; 39 of 49 patients (79.6%) with iLR and 48 of 53 patients (90.6%) with iRR underwent salvage with reirradiation, surgery, thermal ablation, or chemotherapy. Median follow-up times for patients with iLR or iRR were 57.2 months (interquartile range, 37.7-87.6 months) from initial SABR and 38.5 months (interquartile range, 19.9-69.3 months) from recurrence. Rates of overall survival at 5 years from initial SABR were no different between patients with iLR and salvage treatment (57.9%) and patients with no recurrence (54.9%; hazard ratio, 0.89; 95% CI, 0.56-1.43; P = .65) but were lower for patients with iRR and salvage treatment (31.1%; hazard ratio, 1.43; 95% CI, 1.00-2.34; P = .049). Patients receiving salvage treatment had longer overall survival than patients who did not (median, 37 vs 7 months after recurrence; hazard ratio, 0.40; 95% CI, 0.09-0.66; P = .006). Twenty-four of 87 patients (27.6%) who received salvage treatment for iLR or iRR subsequently developed distant metastases. No patient experienced grade 5 toxic effects after salvage treatment.

Conclusions and Relevance

Life expectancy after salvage treatment for iLR was similar to that for patients without recurrence, but survival after salvage treatment for iRR was similar to that of patients with stage III NSCLC. Patients who received salvage treatment had significantly improved survival. Because salvage treatment for iLR or iRR was based on a consistent multidisciplinary approach, this may help in clinical decision making.

Standard and competing risk analysis of the effect of albuminuria on cardiovascular and cancer mortality in patients with type 2 diabetes mellitus

BACKGROUND

Competing risks occur when populations may experience outcomes that either preclude or alter the probability of experiencing the main study outcome(s). Many standard survival analysis methods do not account for competing risks. We used mortality risk in people with diabetes with and without albuminuria as a case study to investigate the impact of competing risks on measures of absolute and relative risk.

METHODS

A population with type 2 diabetes was identified in Clinical Practice Research Datalink as part of a historical cohort study. Patients were followed for up to 9 years. To quantify differences in absolute risk estimates of cardiovascular and cancer, mortality standard (Kaplan-Meier) estimates were compared to competing-risks-adjusted (cumulative incidence competing risk) estimates. To quantify differences in measures of association, regression coefficients for the effect of albuminuria on the relative hazard of each outcome were compared between standard cause-specific hazard (CSH) models (Cox proportional hazards regression) and two competing risk models: the unstratified Lunn-McNeil model, which estimates CSH, and the Fine-Gray model, which estimates subdistribution hazard (SDH).

RESULTS

In patients with normoalbuminuria, standard and competing-risks-adjusted estimates for cardiovascular mortality were 11.1% (95% confidence interval (CI) 10.8-11.5%) and 10.2% (95% CI 9.9-10.5%), respectively. For cancer mortality, these figures were 8.0% (95% CI 7.7-8.3%) and 7.2% (95% CI 6.9-7.5%). In patients with albuminuria, standard and competing-risks-adjusted estimates for cardiovascular mortality were 21.8% (95% CI 20.9-22.7%) and 18.5% (95% CI 17.8-19.3%), respectively. For cancer mortality, these figures were 10.7% (95% CI 10.0-11.5%) and 8.6% (8.1-9.2%). For the effect of albuminuria on cardiovascular mortality, regression coefficient values from multivariable standard CSH, competing risks CSH, and competing risks SDH models were 0.557 (95% CI 0.491-0.623), 0.561 (95% CI 0.494-0.628), and 0.456 (95% CI 0.389-0.523), respectively. For the effect of albuminuria on cancer mortality, these values were 0.237 (95% CI 0.148-0.326), 0.244 (95% CI 0.154-0.333), and 0.102 (95% CI 0.012-0.192), respectively.

CONCLUSIONS

Studies of absolute risk should use methods that adjust for competing risks to avoid over-stating risk, such as the CICR estimator. Studies of relative risk should consider carefully which measure of association is most appropriate for the research question.

Factors influencing early and late readmissions in Australian hospitalised patients and investigating role of admission nutrition status as a predictor of hospital readmissions: a cohort study

OBJECTIVES

Limited studies have identified predictors of early and late hospital readmissions in Australian healthcare settings. Some of these predictors may be modifiable through targeted interventions. A recent study has identified malnutrition as a predictor of readmissions in older patients but this has not been verified in a larger population. This study investigated what predictors are associated with early and late readmissions and determined whether nutrition status during index hospitalisation can be used as a modifiable predictor of unplanned hospital readmissions.

DESIGN

A retrospective cohort study.

SETTING

Two tertiary-level hospitals in Australia.

PARTICIPANTS

All medical admissions ≥18 years over a period of 1 year.

OUTCOMES

Primary objective was to determine predictors of early (0-7 days) and late (8-180 days) readmissions. Secondary objective was to determine whether nutrition status as determined by malnutrition universal screening tool (MUST) can be used to predict readmissions.

RESULTS

There were 11 750 (44.8%) readmissions within 6 months, with 2897 (11%) early and 8853 (33.8%) late readmissions. MUST was completed in 16.2% patients and prevalence of malnutrition during index admission was 31%. Malnourished patients had a higher risk of both early (OR 1.39, 95% CI 1.12 to 1.73) and late readmissions (OR 1.23, 95% CI 1.06 to 128). Weekend discharges were less likely to be associated with both early (OR 0.81, 95% CI 0.74 to 0.91) and late readmissions (OR 0.91, 95% CI 0.84 to 0.97). Indigenous Australians had a higher risk of early readmissions while those living alone had a higher risk of late readmissions. Patients ≥80 years had a lower risk of early readmissions while admission to intensive care unit was associated with a lower risk of late readmissions.

CONCLUSIONS

Malnutrition is a strong predictor of unplanned readmissions while weekend discharges are less likely to be associated with readmissions. Targeted nutrition intervention may prevent unplanned hospital readmissions.

TRIAL REGISTRATION

ANZCTRN 12617001362381; Results.

Clinicopathological Features and Prognosis of Primary GISTs with Tumor Rupture in the Real World

Background

Patients with ruptured gastrointestinal stromal tumor (GIST) are recommended for imatinib adjuvant therapy; however, their clinicopathological features and prognosis in the era of imatinib are unknown.

Patients and Methods

The study cohort included 665 patients with histologically proven primary GISTs who underwent R0 or R1 surgery between 2003 and 2007; the validation cohort included 182 patients between 2000 and 2014. The definitions of tumor rupture in the study included perforation at tumor site, tumor fracture, piecemeal resection including open biopsy, and macroscopic injuries to the pseudocapsule.

Results

Tumor rupture occurred in 21 (3.2%) of 665 and 5 (2.9%) of 182 patients in the study and validation cohort, respectively. Ruptured GISTs were more symptomatic, were larger in size, and had higher mitotic count than nonruptured GISTs but were not associated with tumor location or laparoscopic surgery. GISTs with intraoperative rupture had clinicopathological features and prognostic outcomes similar to those with preoperative rupture. Recurrence rates were higher and median recurrence-free survival (RFS) and overall survival (OS) were shorter with ruptured than nonruptured GIST. Tumor rupture was one of the independent prognostic factors for RFS, but not OS, according to multivariate analysis.

Conclusions

Ruptured GISTs were symptomatic larger tumors with high mitotic activity, frequent relapse, and shorter RFS. Tumor rupture was an independent prognostic factor for RFS, but not for OS, in the era of imatinib.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6505-7) contains supplementary material, which is available to authorized users.

Breast cancer risk is increased in the years following false-positive breast cancer screening

Supplemental Digital Content is available in the text.

A small number of studies have investigated breast cancer (BC) risk among women with a history of false-positive recall (FPR) in BC screening, but none of them has used time-to-event analysis while at the same time quantifying the effect of false-negative diagnostic assessment (FNDA). FNDA occurs when screening detects BC, but this BC is missed on diagnostic assessment (DA). As a result of FNDA, screenings that detected cancer are incorrectly classified as FPR. Our study linked data recorded in the Flemish BC screening program (women aged 50–69 years) to data from the national cancer registry. We used Cox proportional hazards models on a retrospective cohort of 298 738 women to assess the association between FPR and subsequent BC, while adjusting for potential confounders. The mean follow-up was 6.9 years. Compared with women without recall, women with a history of FPR were at an increased risk of developing BC [hazard ratio=2.10 (95% confidence interval: 1.92–2.31)]. However, 22% of BC after FPR was due to FNDA. The hazard ratio dropped to 1.69 (95% confidence interval: 1.52–1.87) when FNDA was excluded. Women with FPR have a subsequently increased BC risk compared with women without recall. The risk is higher for women who have a FPR BI-RADS 4 or 5 compared with FPR BI-RADS 3. There is room for improvement of diagnostic assessment: 41% of the excess risk is explained by FNDA after baseline screening.

Mild antithrombin deficiency and risk of recurrent venous thromboembolism: results from the MEGA follow-up study

Essentials Mild antithrombin deficiency may increase the risk of recurrent venous thromboembolism (VTE). In a cohort study, we stratified patients with VTE to various cut-off antithrombin levels. A 1.6-3.7-fold increased risk of recurrent VTE was observed in the lowest antithrombin categories. Mild antithrombin deficiency (activity < 5th percentile of normal) increases recurrent VTE risk.

SUMMARY

Background Mild antithrombin deficiency (previously defined as antithrombin activity below 70% or 80%) has been associated with a 2.4-3.5-fold increased risk of recurrent venous thromboembolism (VTE). This finding may have implications for duration of antithrombotic therapy in VTE patients with mild antithrombin deficiency. Objectives To externally validate whether mild antithrombin deficiency is a risk factor for recurrent VTE. Methods In a population-based cohort study, patients with a first VTE (n = 2357) were stratified according to percentile cut-off antithrombin levels (< 5th [< 87%], 5-10th [87-92%], > 10th percentile [> 92%]) and functional antithrombin levels (< 70%, 70-80%, > 80%). Results During a median follow-up of 7.4 years, 361 recurrent events occurred (incidence rate, 2.5/100 patient-years). We observed an increased risk of recurrent VTE in the lowest antithrombin activity category (< 5th percentile; < 87%) as compared with antithrombin activity that was > 10th percentile (> 92%), with an adjusted hazard ratio (HR) of 1.5 (95%CI, 1.0-2.3). When analyses were stratified to antithrombin cut-off criteria of< 70% vs. patients with antithrombin activity > 80%, the adjusted HR for venous recurrence was 3.7 (95% CI, 1.4-9.9). Mild antithrombin deficiency was able to predict recurrent VTE over at least 8 years of follow-up and the association remained present when the population was stratified to the presence or absence of thrombosis risk factors. Restriction analyses, where patients who used anticoagulation at time of blood draw and those who reported drinking ≥ 5 glasses alcohol daily were excluded, did not materially affect these outcomes. Conclusion This study confirms that mild antithrombin deficiency is a risk factor for recurrent VTE.

Comparative Effectiveness of Intra-Articular Hyaluronic Acid and Corticosteroid Injections on the Time to Surgical Knee Procedures

BACKGROUND

Use of intra-articular hyaluronic acid (HA) injections to manage knee osteoarthritis (OA) remains controversial because of weak and conflicting evidence. The objective was to evaluate the effectiveness of intra-articular HA injections for knee OA management.

METHODS

A nested cohort of persons with knee OA seeing a specialist was created using a 10% random sample of LifeLink Plus claims (2010-2015) to compare the risk of composite (any) knee surgical interventions, total (TKA)/unicompartmental knee arthroplasty (UKA) and TKA only among HA users and 2 comparison groups: corticosteroid (CS) users and HA/CS nonusers. A high-dimensional propensity score (hdPS) was used to match HA users with CS users and with HA/CS nonusers on background covariates. The risk of surgical interventions among HA users relative to the comparison groups was assessed using Cox proportional hazard models.

RESULTS

Among 13,849 patients, 797 were HA users, 5327 were CS users, and 7725 were HA/CS nonusers. After hdPS matching, the risk of composite surgical interventions did not differ between HA users and HA/CS nonusers (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.67-1.16) and CS users (HR, 0.89; 95% CI, 0.65-1.12). Seven of the 8 sensitivity analyses demonstrated no significant benefit among HA users compared to CS users and HA/CS nonusers. A sensitivity analysis that restricted the study cohort to those who ultimately have knee surgery showed a lower risk of surgery of HA (HR, 0.87; 95% CI, 0.79-0.95).

CONCLUSION

There were no significant differences in the risk of surgical interventions among HA users compared to HA/CS nonusers and CS users after accounting for residual confounding using an hdPS.

Early Prediction of Cardiovascular Disease in Kidney Transplant Recipients

Cardiovascular disease (CVD) is frequent after kidney transplantation (KT). This study investigated CVD prediction in KT by information available before KT or within 6 months after KT. The study cohort consisted of 629 patients with KT in 2005-10 and with adult age at KT. The end point was incidence up to 2015 of CVD (coronary heart disease, cerebrovascular disease, peripheral artery disease). Graft failure, non-CVD death with functioning graft, and loss to follow-up were considered competing events. CVD prediction was investigated for 34 variables by means of competing-risks regression. Follow-up range was 0.28-10.00 years (mean ± SD, 7.30 ± 3.10). First incident event was CVD in 103 patients and competing events in 146 patients. In the multivariable model for pre-KT variables only, CVD predictors were male sex (hazard ratio [HR], 1.68; 95% confidence interval [CI], 1.06-2.66), diabetic nephropathy (HR, 6.63; 95% CI, 1.81-24.35), pre-KT dialysis for ≥5 years (HR, 1.52; 95% CI, 1.02-2.27), pre-KT CVD (HR, 4.87; 95% CI, 2.84-8.35), and age at KT ≥45 years (HR, 2.98; 95% CI, 1.83-4.87). In the model for pre-KT and post-KT variables together, the sole post-KT CVD predictor was estimated glomerular filtration rate <60 mL/min at the 6-month visit (HR, 1.75; 95% CI, 1.11-2.77). Diabetic nephropathy, pre-KT dialysis, pre-KT CVD, and age at KT predicted 91.2% of incident CVD. Early available information effectively predicted CVD in KT independently from competing events.