Background Limited evidence existed on the comparative effectiveness of decompressive craniectomy (DC) versus craniotomy for evacuation of traumatic acute subdural hematoma (ASDH) until the... Show moreBackground Limited evidence existed on the comparative effectiveness of decompressive craniectomy (DC) versus craniotomy for evacuation of traumatic acute subdural hematoma (ASDH) until the recently published randomised clinical trial RESCUE-ASDH. In this study, that ran concurrently, we aimed to determine current practice patterns and compare outcomes of primary DC versus craniotomy.Methods We conducted an analysis of centre treatment preference within the prospective, multicentre, observational Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (known as CENTER-TBI) and NeuroTraumatology Quality Registry (known as Net-QuRe) studies, which enrolled patients throughout Europe and Israel (2014-2020). We included patients with an ASDH who underwent acute neurosurgical evacuation. Patients with severe pre-existing neurological disorders were excluded. In an instrumental variable analysis, we compared outcomes between centres according to treatment preference, measured by the case-mix adjusted proportion DC per centre. The primary outcome was functional outcome rated by the 6-months Glasgow Outcome Scale Extended, estimated with ordinal regression as a common odds ratio (OR), adjusted for prespecified confounders. Variation in centre preference was quantified with the median odds ratio (MOR). CENTER-TBI is registered with ClinicalTrials.gov, number NCT02210221, and the Resource Identification Portal (Research Resource Identifier SCR_015582).Findings Between December 19, 2014 and December 17, 2017, 4559 patients with traumatic brain injury were enrolled in CENTER-TBI of whom 336 (7%) underwent acute surgery for ASDH evacuation; 91 (27%) underwent DC and 245 (63%) craniotomy. The proportion primary DC within total acute surgery cases ranged from 6 to 67% with an interquartile range (IQR) of 12-26% among 46 centres; the odds of receiving a DC for prognostically similar patients in one centre versus another randomly selected centre were trebled (adjusted median odds ratio 2.7, p < 0.0001). Higher centre preference for DC over craniotomy was not associated with better functional outcome (adjusted common odds ratio (OR) per 14% [IQR increase] more DC in a centre = 0.9 [95% CI 0.7-1.1], n = 200). Primary DC was associated with more follow-on surgeries and complications [secondary cranial surgery 27% vs. 18%; shunts 11 vs. 5%]; and similar odds of in-hospital mortality (adjusted OR per 14% IQR more primary DC 1.3 [95% CI (1.0-3.4), n = 200]).Interpretation We found substantial practice variation in the employment of DC over craniotomy for ASDH. This variation in treatment strategy did not result in different functional outcome. These findings suggest that primary DC should be restricted to salvageable patients in whom immediate replacement of the bone flap is not possible due to intraoperative brain swelling. Show less
A traumatic acute subdural hematoma, a bleeding between the skull and the brain after a traumatic injury, is associated with high mortality and long-term neurocognitive morbidity. One of the age... Show moreA traumatic acute subdural hematoma, a bleeding between the skull and the brain after a traumatic injury, is associated with high mortality and long-term neurocognitive morbidity. One of the age-old cornerstones of treatment is immediate neurosurgical management, with either acute hematoma evacuation or initial conservative treatment with potential delayed surgery. In patients with rapid neurological deterioration because of a large acute subdural hematoma, the indication is clear; without acute surgery, high intracranial pressure will persist and the patient will die. In most cases however, the benefit of acute surgery is less clear, and patients may, at least initially, be managed conservatively. This strategy requires balancing potential complications of surgery against the risk of irreversible neurological deterioration with initial conservative treatment.Neurosurgeon Thomas van Essen first shows that appropriate evidence of acute surgery versus conservative treatment for acute subdural hematoma is lacking, although among comatose patients, acute surgery has a clear benefit. Subsequently, he demonstrates that among neurosurgeons treatment preferences strongly and consistently differ, resulting in large practice variations. Using these treatment preferences, he then shows that patients treated in centers that prefer acute surgery (over conservative treatment) have equal outcomes to patients treated in centers that prefer conservative treatment. Additionally, with regard to surgical technique, primary decompressive craniectomy - leaving the bone flap out after evacuation of the acute subdural hematoma - might not lead to better outcomes as compared to craniotomy – replacing the bone flap directly. The thesis has practical implications for clinical practice: When the neurosurgeon has no clear preference for acute surgery or conservative treatment, treat patients with a traumatic acute subdural hematoma conservatively. And, primary decompressive craniectomy in traumatic acute subdural hematoma should be restricted to patients in whom replacement of the bone flap is not possible due to severe brain swelling. Show less
Due to a shorter remaining life expectancy, the risk of recurrence in older patients with low risk breast cancer is often reduced and the benefit of treatments may be very limited, especially with... Show moreDue to a shorter remaining life expectancy, the risk of recurrence in older patients with low risk breast cancer is often reduced and the benefit of treatments may be very limited, especially with adjuvant treatments. In the first part of this thesis, we studied the interplay between breast cancer mortality and other-cause mortality. In the second part of this thesis, we investigated the effect of surgery and radiotherapy in subsets of the older population of patients with breast cancer in which the actual treatment effect is questionable. Show less
Schaapherder, A.F.; Kaisar, M.; Mumford, L.; Robb, M.; Johnson, R.; Kok, M.J.C.D.; ... ; Lindeman, J.H.N. 2022
Background: Donor-characteristics and donor characteristics-based decision algorithms are being progressively used in the decision process whether or not to accept an available donor kidney graft... Show moreBackground: Donor-characteristics and donor characteristics-based decision algorithms are being progressively used in the decision process whether or not to accept an available donor kidney graft for transplantation. While this may improve outcomes, the performance characteristics of the algorithms remains moderate. To estimate the impact of donor factors of grafts accepted for transplantation on transplant outcomes, and to test whether implementation of donor-characteristics-based algorithms in clinical decision-making is justified, we applied an instrumental variable analysis to outcomes for kidney donor pairs transplanted in different individuals. Methods: This analysis used (dis)congruent outcomes of kidney donor pairs as an instrument and was based on national transplantation registry data for all donor kidney pairs transplanted in separate individuals in the Netherlands (1990-2018, 2,845 donor pairs), and the United Kingdom (UK, 2000-2018, 11,450 pairs). Incident early graft loss (EGL) was used as the primary discriminatory factor. It was reasoned that a scenario with a dominant impact of donor variables on transplantation outcomes would result in high concordance of EGL in both recipients, whilst dominance of asymmetrical outcomes could indicate a more complex scenario, involving an interaction of donor, procedural and recipient factors. Findings: Incidences of congruent EGL (Netherlands: 1.2%, UK: 0.7%) were slightly lower than the arithmetical (stochastic) incidences, suggesting that once a graft has been accepted for transplantation, donor factors minimally contribute to incident EGL. A long-term impact of donor factors was explored by comparing outcomes for functional grafts from donor pairs with asymmetrical vs. symmetrical outcomes. Recipient survival was similar for both groups, but a slightly compromised graft survival was observed for grafts with asymmetrical outcomes in the UK cohort: (10 years Hazard Ratio for graft loss: 1.18 [1.03-1.35] p < 0.018); and 5 years eGFR (48.6 [48.3-49.0] vs. 46.0 [44.5-47.6] ml/min in the symmetrical outcome group, p < 0.001). Interpretation: Our results suggest that donor factors for kidney grafts deemed acceptable for transplantation impact minimally on transplantation outcomes. A strong reliance on donor factors and/or donor-characteristics-based decision algorithms could result in unjustified rejection of grafts. Future efforts to optimize transplant outcomes should focus on a better understanding of the recipient factors underlying transplant outcomes. Copyright (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Show less
Ceyisakar, I.E.; Leeuwen, N. van; Steyerberg, E.W.; Lingsma, H.F. 2022
Background: Instrumental variable (IV) analysis holds the potential to estimate treatment effects from observational data. IV analysis potentially circumvents unmeasured confounding but makes a... Show moreBackground: Instrumental variable (IV) analysis holds the potential to estimate treatment effects from observational data. IV analysis potentially circumvents unmeasured confounding but makes a number of assumptions, such as that the IV shares no common cause with the outcome. When using treatment preference as an instrument, a common cause, such as a preference regarding related treatments, may exist. We aimed to explore the validity and precision of a variant of IV analysis where we additionally adjust for the provider: adjusted IV analysis. Methods: A treatment effect on an ordinal outcome was simulated (beta - 0.5 in logistic regression) for 15.000 patients, based on a large data set (the IMPACT data, n = 8799) using different scenarios including measured and unmeasured confounders, and a common cause of IV and outcome. We compared estimated treatment effects with patient-level adjustment for confounders, IV with treatment preference as the instrument, and adjusted IV, with hospital added as a fixed effect in the regression models. Results: The use of patient-level adjustment resulted in biased estimates for all the analyses that included unmeasured confounders, IV analysis was less confounded, but also less reliable. With correlation between treatment preference and hospital characteristics (a common cause) estimates were skewed for regular IV analysis, but not for adjusted IV analysis. Conclusion: When using IV analysis for comparing hospitals, some limitations of regular IV analysis can be overcome by adjusting for a common cause. Show less
