scholarly journals Extrapolating Survival from Randomized Trials Using External Data: A Review of Methods

2016 ◽  
Vol 37 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Christopher Jackson ◽  
John Stevens ◽  
Shijie Ren ◽  
Nick Latimer ◽  
Laura Bojke ◽  
...  
Keyword(s):  
Survival Data ◽  
Randomized Trials ◽  
Research Priorities ◽  
Future Research ◽  
Term Survival ◽  
Individual Level ◽  
External Data ◽  
The United Kingdom ◽  
Term Data

This article describes methods used to estimate parameters governing long-term survival, or times to other events, for health economic models. Specifically, the focus is on methods that combine shorter-term individual-level survival data from randomized trials with longer-term external data, thus using the longer-term data to aid extrapolation of the short-term data. This requires assumptions about how trends in survival for each treatment arm will continue after the follow-up period of the trial. Furthermore, using external data requires assumptions about how survival differs between the populations represented by the trial and external data. Study reports from a national health technology assessment program in the United Kingdom were searched, and the findings were combined with “pearl-growing” searches of the academic literature. We categorized the methods that have been used according to the assumptions they made about how the hazards of death vary between the external and internal data and through time, and we discuss the appropriateness of the assumptions in different circumstances. Modeling choices, parameter estimation, and characterization of uncertainty are discussed, and some suggestions for future research priorities in this area are given.

scholarly journals Is It Definitely Clear That Long-Term Survival after Breast Cancer Surgery Is Not Affected by Anaesthetics?

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3390
Author(s):  
Mats Enlund
Keyword(s):  
Breast Cancer ◽  
Survival Data ◽  
Retrospective Studies ◽  
Breast Cancer Surgery ◽  
Breast Cancer Patients ◽  
Term Survival ◽  
Long Term Survival ◽  
Significant Difference ◽  
One Year

Retrospective studies indicate that cancer survival may be affected by the anaesthetic technique. Propofol seems to be a better choice than volatile anaesthetics, such as sevoflurane. The first two retrospective studies suggested better long-term survival with propofol, but not for breast cancer. Subsequent retrospective studies from Asia indicated the same. When data from seven Swedish hospitals were analysed, including 6305 breast cancer patients, different analyses gave different results, from a non-significant difference in survival to a remarkably large difference in favour of propofol, an illustration of the innate weakness in the retrospective design. The largest randomised clinical trial, registered on clinicaltrial.gov, with survival as an outcome is the Cancer and Anesthesia study. Patients are here randomised to propofol or sevoflurane. The inclusion of patients with breast cancer was completed in autumn 2017. Delayed by the pandemic, one-year survival data for the cohort were presented in November 2020. Due to the extremely good short-term survival for breast cancer, one-year survival is of less interest for this disease. As the inclusions took almost five years, there was also a trend to observe. Unsurprisingly, no difference was found in one-year survival between the two groups, and the trend indicated no difference either.

xtgeebcv: A command for bias-corrected sandwich variance estimation for GEE analyses of cluster randomized trials

2020 ◽  
Vol 20 (2) ◽  
pp. 363-381 ◽  
Author(s):  
John A. Gallis ◽  
Fan Li ◽  
Elizabeth L. Turner
Keyword(s):  
Randomized Trials ◽  
Variance Estimation ◽  
Public Health Education ◽  
Standard Errors ◽  
Future Research ◽  
Type I ◽  
Cluster Randomized Trials ◽  
Finite Sample ◽  
Individual Level ◽  
Cluster Randomized

Cluster randomized trials, where clusters (for example, schools or clinics) are randomized to comparison arms but measurements are taken on individuals, are commonly used to evaluate interventions in public health, education, and the social sciences. Analysis is often conducted on individual-level outcomes, and such analysis methods must consider that outcomes for members of the same cluster tend to be more similar than outcomes for members of other clusters. A popular individual-level analysis technique is generalized estimating equations (GEE). However, it is common to randomize a small number of clusters (for example, 30 or fewer), and in this case, the GEE standard errors obtained from the sandwich variance estimator will be biased, leading to inflated type I errors. Some bias-corrected standard errors have been proposed and studied to account for this finite-sample bias, but none has yet been implemented in Stata. In this article, we describe several popular bias corrections to the robust sandwich variance. We then introduce our newly created command, xtgeebcv, which will allow Stata users to easily apply finite-sample corrections to standard errors obtained from GEE models. We then provide examples to demonstrate the use of xtgeebcv. Finally, we discuss suggestions about which finite-sample corrections to use in which situations and consider areas of future research that may improve xtgeebcv.

scholarly journals Long-term survival data from a clinical trial on resin-bonded bridges

1997 ◽  
Vol 25 (3-4) ◽  
pp. 239-242 ◽  
Author(s):  
N.H.J. Creugers ◽  
R.J.A.M. De Kanter ◽  
M.A. van't Hof
Keyword(s):  
Clinical Trial ◽  
Survival Data ◽  
Term Survival ◽  
Long Term Survival

scholarly journals Concomitant tricuspid regurgitation severity and its secondary reduction determine long-term prognosis after transcatheter mitral valve edge-to-edge repair

2021 ◽  
Author(s):  
Martin Geyer ◽  
Karsten Keller ◽  
Kevin Bachmann ◽  
Sonja Born ◽  
Alexander R. Tamm ◽  
...  
Keyword(s):  
Tricuspid Regurgitation ◽  
Survival Data ◽  
Common Finding ◽  
Prognostic Impact ◽  
Term Survival ◽  
Long Term Prognosis ◽  
The Impact ◽  
Symptomatic Benefit

Abstract Background Concomitant tricuspid regurgitation (TR) is a common finding in mitral regurgitation (MR). Transcatheter repair (TMVR) is a favorable treatment option in patients at elevated surgical risk. To date, evidence on long-term prognosis and the prognostic impact of TR after TMVR is limited. Methods Long-term survival data of patients undergoing isolated edge-to-edge repair from June 2010 to March 2018 (combinations with other forms of TMVR or tricuspid valve therapy excluded) were analyzed in a retrospective monocentric study. TR severity was categorized and the impact of TR on survival was analysed. Results Overall, 606 patients [46.5% female, 56.4% functional MR (FMR)] were enrolled in this study. TR at baseline was categorized severe/medium/mild/no or trace in 23.2/34.3/36.3/6.3% of the cases. At 30-day follow-up, improvement of at least one TR-grade was documented in 34.9%. Severe TR at baseline was identified as predictor of 1-year survival [65.2% vs. 77.0%, p = 0.030; HR for death 1.68 (95% CI 1.12–2.54), p = 0.013] and in FMR-patients also regarding long-term prognosis [adjusted HR for long-term mortality 1.57 (95% CI 1.00–2.45), p = 0.049]. Missing post-interventional reduction of TR severity was predictive for poor prognosis, especially in the FMR-subgroup [1-year survival: 92.9% vs. 78.3%, p = 0.025; HR for death at 1-year follow-up 3.31 (95% CI 1.15–9.58), p = 0.027]. While BNP levels decreased in both subgroups, TR reduction was associated with improved symptomatic benefit (NYHA-class-reduction 78.6 vs. 65.9%, p = 0.021). Conclusion In this large study, both, severe TR at baseline as well as missing secondary reduction were predictive for impaired long-term prognosis, especially in patients with FMR etiology. TR reduction was associated with increased symptomatic benefit. Graphic abstract

CURE OF THREE PATIENTS WHO HAD SKELETAL METASTASES IN DISSEMINATED NEUROBLASTOMA

PEDIATRICS ◽  
1968 ◽  
Vol 41 (1) ◽  
pp. 47-51
Author(s):  
Douglas Reilly ◽  
Mark E. Nesbit ◽  
William Krivit
Keyword(s):  
Overall Survival ◽  
Survival Data ◽  
Specific Treatment ◽  
Skeletal Metastases ◽  
University Of Minnesota ◽  
Term Survival ◽  
Long Term Survival ◽  
Skeletal Involvement ◽  
The University

The long-term survival of three children with disseminated skeletal metastases due to neuroblastoma is reported. These three patients are added to eight other patients reported in the literature who have survived longer than 2 years after the development of their metastatic osseous lesions. A review of the cases did not reveal a specific treatment regime which provided the success in these cases. The presence of skeletal involvement, therefore, should not indicate a hopeless prognosis. A review of 33 patients with neuroblastoma at the University of Minnesota from 1956-1966 is also given to provide overall survival data.

Conclusion: What academia can contribute to refugee policy

2018 ◽  
Vol 56 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Idean Salehyan
Keyword(s):  
Academic Research ◽  
Forced Migration ◽  
Humanitarian Assistance ◽  
Future Research ◽  
Security Risks ◽  
Individual Level ◽  
The Public ◽  
Level Data ◽  
Potential Risks

This conclusion to the special issue highlights the role of scholars in advancing the public discussion about forced migration. As countries around the world are adopting increasing restrictions on the entry of refugees, academic research can help to dispel some of the myths and apprehensions regarding the risks that forced migration entails. While refugees may be linked to conflict and violence in limited circumstances, the research generally demonstrates that robust international cooperation to manage refugee settlements, provide adequate humanitarian assistance, and integrate refugees into host communities, among other policies, can help to mitigate potential risks. Directions for future research and analysis are also discussed. Forced migration scholars should endeavor to collect more individual-level data; seek to understand factors that exacerbate or reduce security risks associated with cross-border militancy; conduct research on the long-term integration of refugees; and seek to understand the causes and consequences of resettlement and repatriation policies.

scholarly journals New insights and long-term safety of tocilizumab in rheumatoid arthritis

2018 ◽  
Vol 10 (10) ◽  
pp. 195-199 ◽  
Author(s):  
Graeme Jones ◽  
Elena Panova
Keyword(s):  
Rheumatoid Arthritis ◽  
Observational Studies ◽  
Randomized Trials ◽  
Treatment Options ◽  
Safety Data ◽  
Signs And Symptoms ◽  
Western Society ◽  
Interleukin 6 Receptor ◽  
Term Data

Rheumatoid arthritis is a leading musculoskeletal cause of disability in Western society. Therapeutic options have expanded rapidly with the advent of biological agents as treatment options. One of these, tocilizumab, targets the interleukin-6 receptor and has been approved since the late 2000s in many jurisdictions. This approval was based on 6–12 month trials. It is now appropriate to look at longer-term studies and what new insights they have provided into this agent. Data are based largely on observational studies with their well-known limitations as well as some further randomized trials and provide a number of important observations regarding both efficacy and safety. In conclusion, the longer-term data suggest tocilizumab efficacy increases over time for both signs and symptoms and radiographic change. It is also corticosteroid sparing. The safety data are consistent with the shorter-term trials and are largely reassuring but some questions still remain over cardiovascular safety and cancer risk.

scholarly journals Power analyses for moderator effects with (non)randomly varying slopes in cluster randomized trials

Methodology ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 92-110
Author(s):  
Nianbo Dong ◽  
Jessaca Spybrook ◽  
Benjamin Kelcey ◽  
Metin Bulus
Keyword(s):  
Statistical Power ◽  
Randomized Trials ◽  
Future Research ◽  
Size Difference ◽  
Detectable Effect ◽  
Cluster Randomized Trials ◽  
Individual Level ◽  
Moderator Effects ◽  
Cluster Randomized ◽  
Power Analyses

Researchers often apply moderation analyses to examine whether the effects of an intervention differ conditional on individual or cluster moderator variables such as gender, pretest, or school size. This study develops formulas for power analyses to detect moderator effects in two-level cluster randomized trials (CRTs) using hierarchical linear models. We derive the formulas for estimating statistical power, minimum detectable effect size difference and 95% confidence intervals for cluster- and individual-level moderators. Our framework accommodates binary or continuous moderators, designs with or without covariates, and effects of individual-level moderators that vary randomly or nonrandomly across clusters. A small Monte Carlo simulation confirms the accuracy of our formulas. We also compare power between main effect analysis and moderation analysis, discuss the effects of mis-specification of the moderator slope (randomly vs. non-randomly varying), and conclude with directions for future research. We provide software for conducting a power analysis of moderator effects in CRTs.

Coronary artery bypass and valve surgery

2020 ◽  
pp. 3666-3673
Author(s):  
Rana Sayeed ◽  
David Taggart
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Bypass ◽  
Artery Bypass ◽  
Ventricular Myocardium ◽  
Risk Profile ◽  
Valve Surgery ◽  
Valvular Regurgitation ◽  
Term Survival ◽  
The United Kingdom

The two main indications for coronary artery bypass grafting (CABG) are for relief of symptoms, usually angina and/or breathlessness, that persist even with optimal medical therapy, and/or prognosis. There is a prognostic benefit for CABG in patients with large volumes of ischaemia (i.e. affecting >12% of the ventricular myocardium), and the benefit of revascularization increases with increasing volumes of ischaemia. The overall mortality for elective CABG in the United Kingdom is around 1% and has continued to fall over the last decade despite an increasingly adverse risk profile of patients undergoing surgery. Valve surgery is primarily performed for patients with severe valvular disease and symptoms. Indications also include deteriorating ventricular function and the requirement for coronary artery surgery in patients with coexistent valve disease. Mitral valve repair is a highly successful procedure in patients with non-rheumatic valvular regurgitation and is associated with an excellent long-term survival.

scholarly journals Pleural infection—an indicator of morbidity and increased burden on health care

2020 ◽  
Vol 31 (4) ◽  
pp. 513-518
Author(s):  
Antti I Lehtomäki ◽  
Riikka M Nevalainen ◽  
Vesa J Toikkanen ◽  
Emilia S Pohja ◽  
Jaakko J Nieminen ◽  
...  
Keyword(s):  
Emergency Room ◽  
Survival Data ◽  
Healthcare Services ◽  
University Hospital ◽  
P Value ◽  
Term Survival ◽  
Frequent Use ◽  
Clinic Visits

Abstract OBJECTIVES Patients with pleural infections frequently have several comorbidities and inferior long-term survival. We hypothesized that these patients represent a vulnerable cohort with high rates of hospitalization and frequent use of healthcare services. This study aims to ascertain the need for and causes of treatment episodes after pleural infections during long-term follow-up. METHODS Patients treated for pleural infections at Tampere University Hospital between January 2000 and December 2008 (n = 191, 81% males, median age 58 years) were included and compared to a demographically matched population-based random sample of 1910 controls. Seventy percent of the pleural infections were caused by pneumonias and 80% of the patients underwent surgery. Information regarding later in-hospital periods and emergency room and out-patient clinic visits, as well as survival data, was obtained from national registries and compared between patients and controls. RESULTS Patients treated for pleural infections had significantly higher rates of hospitalizations (8.19 vs 2.19), in-hospital days (88.5 vs 26.6), emergency room admissions (3.18 vs 1.45), out-patient clinic visits (41.1 vs 11.8) and procedures performed (1.26 vs 0.55) per 100 patient-months when compared to controls during 5-year follow-up, in addition to having increased mortality (30% vs 11%), P-value <0.00001 each. Particularly, episodes due to respiratory and digestive diseases, malignancies and mental disorders were more frequent. The patients’ comorbidities, such as alcoholism or chronic pulmonary disease, were associated with more frequent use of healthcare services. CONCLUSIONS Patients treated for pleural infections have high rates of hospitalizations, emergency room admissions and out-patient clinic visits during follow-up.

Sign in / Sign up

Export Citation Format

Share Document