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1.
Epidemiology ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38967970

RESUMEN

In placebo-controlled randomized clinical trials, adherence to the placebo is often supposed to have no effect on the primary outcome of interest: when unbiased methods are used, investigators expect to estimate a null effect. Estimating the 'effect' of adherence to placebo in these settings has thus been proposed and popularized as a strategy for detecting bias, for example, from unmeasured confounding. This strategy can be viewed as an application of a type of negative control exposure, which we term a placebo-adherence negative control exposure. Here, we formally state its defining assumptions and discuss the unique advantages of single-world intervention graphs for reasoning about them.

2.
Ann Surg Oncol ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39048903

RESUMEN

BACKGROUND: Axillary dissection is the standard of care for patients with positive sentinel lymph nodes (SLNs) following neoadjuvant systemic therapy. Frozen section can provide intraoperative information regarding the need for axillary dissection during the index operation. However, there are limited data on the utility of frozen section in patients with clinically node-negative (cN0) HER2-positive or triple-negative breast cancer. METHODS: We conducted a single-institution observational cohort study including patients with non-inflammatory, cN0, HER2-positive or triple-negative breast cancer treated with neoadjuvant systemic therapy between 2015 and 2019. We estimated the prevalence of SLN positivity and the diagnostic test characteristics of SLN frozen section. RESULTS: Overall, 662 patients were eligible for inclusion, and 44 patients had one or more positive SLNs (prevalence: 6.6%, 95% confidence interval [CI] 4.9-8.8). There were 490 (74.0%) patients who had intraoperative frozen section, and 19 (3.9%) tested positive among 33 (6.7%) with positive final pathology. Frozen section sensitivity was 57.6% (95% CI 39.2-74.5), specificity was 100% (95% CI 99.2-100), positive predictive value was 100% (95% CI 82.4-100), and negative predictive value was 97.0% (95% CI 95.1-98.4). The sensitivity of frozen section for detection of micrometastases or isolated tumor cells was 35.3% (95% CI 14.2-61.7). CONCLUSION: In patients with cN0 HER2-positive or triple-negative breast cancer who have been treated with neoadjuvant therapy, positive SLNs are uncommon and frozen section sensitivity is modest. Decisions to defer SLN evaluation to final pathology, which may be reasonable in many settings, can be informed, in part, by these findings.

3.
JAMA Surg ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39046752

RESUMEN

This cohort study compares survival outcomes between patients with unresectable colorectal liver metastasis who received chemotherapy-based multimodal therapy and patients who underwent liver transplant.

4.
Epidemiology ; 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39024034

RESUMEN

BACKGROUND: Observational studies have estimated strongly protective effects of bariatric surgery on cardiovascular disease, but with oversimplified definitions of the intervention, eligibility criteria, and follow-up, which deviate from those in a randomized trial. We describe studying the effect of bariatric surgery on cardiovascular disease without introducing these sources of bias, which may not be entirely possible with existing observational data. METHODS: We propose target trials among persons with diabetes: (1) bariatric operation (vs. no operation) among individuals who have undergone pre-operative preparation (lifestyle modifications, screening) and (2) pre-operative preparation and bariatric surgery (vs. neither pre-operative nor operative component). RESULTS: We emulated both target trials using observational data of U.S. veterans. Comparing bariatric surgery with no surgery (target trial #1; 8,087 individuals), the 7-year cardiovascular risk was 18.0% (95% CI, 6.9 to 32.7) in the surgery group and 18.9% (95% CI, 17.7 to 20.1) in the no surgery group (risk difference -0.9, 95% CI -12.0 to 14.0). Comparing pre-operative components plus surgery vs. neither (target trial #2; 10,065 individuals), the 7-year cardiovascular risk was 17.4% (95% CI, 13.6 to 22.0) in the surgery group and 18.8% (95% CI, 17.8 to 19.9) in the no surgery group (risk difference -1.4, 95% CI -5.1 to 3.2). Body mass index and hemoglobin A1c were reduced with bariatric interventions in both emulations. CONCLUSIONS: Within limitations of available observational data, our estimates do not provide evidence that bariatric surgery reduces cardiovascular disease and support equipoise for a randomized trial of bariatric surgery for cardiovascular disease prevention.

5.
Ann Surg Oncol ; 2024 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-39034365

RESUMEN

BACKGROUND: Inflammatory breast cancer (IBC) is rare and biologically aggressive. We sought to assess diagnostic and management strategies among the American Society of Breast Surgeons (ASBrS) membership. PATIENTS AND METHODS: An anonymous survey was distributed to ASBrS members from March to May 2023. The survey included questions about respondents' demographics and information related to stage III and IV IBC management. Agreement was defined as a shared response by >80% of respondents. In areas of disagreement, responses were stratified by years in practice, fellowship training, and annual IBC patient volume. RESULTS: The survey was administered to 2337 members with 399 (17.1%) completing all questions and defining the study cohort. Distribution of years in practice was 26.0% 0-10 years, 26.6% 11-20 years and 47.4% > 20 years. Overall, 51.2% reported surgical oncology or breast fellowship training, 69.2% maintain a breast-only practice, and 73.5% treat < 5 IBC cases/year. Agreement was identified in diagnostic imaging, trimodal therapy, and mastectomy with wide skin excision for stage III IBC. Lack of agreement was identified in surgical management of the axilla; respondents with < 10 years in practice or fellowship training were more likely to perform axillary dissection for cN0-N2 stage III IBC. Locoregional management of stage IV IBC was variable. CONCLUSIONS: Among ASBrS members, there is consensus in diagnostic evaluation, treatment sequencing and surgical approach to the breast in stage III IBC. Differences exist in surgical management of the cN0-2 axilla with uptake of de-escalation strategies. Clinical trials are needed to evaluate oncologic safety of de-escalation in this high-risk population.

6.
JAMA Netw Open ; 7(6): e2418486, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38916888

RESUMEN

Importance: Although most women with BRCA-associated breast cancer choose bilateral mastectomy, current guidelines support breast-conserving therapy as an option. As the indications for genetic testing expand and targeted therapies emerge, understanding the outcomes of breast-conserving therapy in the population of patients choosing breast conservation is important. Objective: To describe the clinical outcomes of women with BRCA-associated breast cancer who were treated with breast-conserving therapy, including the risks of ipsilateral and contralateral cancer events and bilateral mastectomy-free survival. Design, Setting, and Participants: This cohort study conducted at a single-institution academic national comprehensive cancer center included 172 women identified from a prospectively maintained database who had pathogenic BRCA1/2 variants and were treated with breast-conserving therapy from January 1, 1977, to December 31, 2021. Main Outcomes and Measures: Clinical and pathologic characteristics for patients with BRCA1 and BRCA2 were compared, and estimates of overall survival, bilateral mastectomy-free survival, distant disease-free survival, risk of ipsilateral breast cancer, and risk of contralateral cancer were computed. Results: The cohort included 172 women (mean [SD] age, 47.1 [11.7] years), with 42 (24.4%) receiving a diagnosis of breast cancer prior to 40 years of age. Compared with BRCA2 variant carriers (80 [46.5%]), women with BRCA1 variants (92 [53.5%]) were younger at breast cancer diagnosis and tended to have more advanced tumors, which were more likely to be hormone receptor negative and higher grade. At a median follow-up of 11.8 years (IQR, 5.7-18.2 years), estimates of 10-year survival and risk were: overall survival, 88.5% (95% CI, 83.1%-94.2%); bilateral mastectomy-free survival, 70.7% (95% CI, 63.3%-78.9%); risk of an ipsilateral breast cancer event, 12.2% (95% CI, 5.8%-18.2%); and risk of contralateral cancer, 21.3% (95% CI, 13.3%-28.6%). Risks continued to increase after 10 years of follow-up. Conclusions and Relevance: In this cohort study, although women with breast cancer and pathogenic BRCA1/2 variants treated with breast-conserving therapy had above-average risks of ipsilateral and contralateral breast cancer events, most did not have another cancer event and remained bilateral mastectomy free. These findings may be useful for informing patients with BRCA variants choosing breast conservation.


Asunto(s)
Neoplasias de la Mama , Mastectomía Segmentaria , Humanos , Femenino , Persona de Mediana Edad , Neoplasias de la Mama/genética , Neoplasias de la Mama/cirugía , Adulto , Proteína BRCA2/genética , Proteína BRCA1/genética , Estudios de Cohortes , Resultado del Tratamiento , Supervivencia sin Enfermedad
7.
Eur J Epidemiol ; 38(10): 1019-1023, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37667140

RESUMEN

Despite their pre- and postoperative components, surgical treatment strategies have typically been cast as point interventions in causal inference research. When longitudinal perioperative components affect outcomes of interest, leaving them unspecified or failing to measure adherence to them complicates the interpretation of effect estimates. Inspired by two recent landmark trials that assessed the risk of stroke or death after transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR), the PARTNER 3 trial and the Evolut Low Risk trial, we discuss possible ways that different postoperative therapies in treatment arms and incomplete adherence to those therapies can impact the interpretation of intention-to-treat effect estimates in surgical trials. We argue that surgical treatments are not necessarily point interventions, and make recommendations for improving the design and analysis of trials involving surgical interventions. Central to these recommendations is the need for investigators to specify and report adherence to longitudinal perioperative treatment components.


Asunto(s)
Estenosis de la Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Estenosis de la Válvula Aórtica/cirugía , Resultado del Tratamiento , Válvula Aórtica/cirugía , Factores de Riesgo
8.
Chest ; 164(4): 885-891, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37150505

RESUMEN

BACKGROUND: Whether intubation should be initiated early in the clinical course of critically ill patients remains a matter of debate. Results from prior observational studies are difficult to interpret because of avoidable flaws including immortal time bias, inappropriate eligibility criteria, and unrealistic treatment strategies. RESEARCH QUESTION: Do treatment strategies that intubate patients early in the critical care admission improve 30-day survival compared with strategies that delay intubation? STUDY DESIGN AND METHODS: We estimated the effect of strategies that require early intubation of critically ill patients compared with those that delay intubation. With data extracted from the Medical Information Mart for Intensive Care-IV database, we emulated three target trials, varying the flexibility of the treatment strategies and the baseline eligibility criteria. RESULTS: Under unrealistically strict treatment strategies with broad eligibility criteria, the 30-day mortality risk was 7.1 percentage points higher for intubating early compared with delaying intubation (95% CI, 6.2-7.9). Risk differences were 0.4 (95% CI, -0.1 to 0.9) and -0.9 (95% CI, -2.5 to 0.7) percentage points in subsequent target trial emulations that included more realistic treatment strategies and eligibility criteria. INTERPRETATION: When realistic treatment strategies and eligibility criteria are used, strategies that delay intubation result in similar 30-day mortality risks compared with those that intubate early. Delaying intubation ultimately avoids intubation in most patients.


Asunto(s)
Enfermedad Crítica , Ventilación no Invasiva , Humanos , Enfermedad Crítica/terapia , Respiración Artificial , Ventilación no Invasiva/métodos , Intubación Intratraqueal , Cuidados Críticos
9.
World J Surg ; 46(10): 2476-2486, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35835863

RESUMEN

BACKGROUND: In Ukraine, there is no established colorectal cancer screening program. We aimed to project the number of screening colonoscopies needed for implementation of various CRC screening strategies in Ukraine. METHODS: We modified a previously developed Markov microsimulation model to reflect the natural history of adenoma and CRC progression among average-risk 50-74-year-olds. We simulated colonoscopies needed for the following screening strategies: no screening, fecal occult blood test yearly, FOBT yearly with flexible sigmoidoscopy every 5 years, FS every 5 years, fecal immunohistochemistry test (FIT) yearly, or colonoscopy every 10 years. Assuming 80% screening adherence, we estimated colonoscopies required at 1 and 5 years depending on the implementation rate. In one-way sensitivity analyses, we varied implementation rate, screening adherence, sensitivity, and specificity. RESULTS: Assuming an 80% screening adherence and complete implementation (100%), besides a no screening strategy, the fewest screening colonoscopies are needed with an FOBT program, requiring on average 6,600 and 26,800 colonoscopies per 100,000 persons at 1 and 5 years post-implementation, respectively. The most screening colonoscopies are required with a colonoscopy program, requiring on average 76,600 and 101,000 colonoscopies per 100,000 persons at 1 and 5 years post-implementation, respectively. In sensitivity analyses, the biggest driver of number of colonoscopies needed was screening adherence. CONCLUSIONS: The number of colonoscopies needed and therefore the potential strain on the healthcare system vary substantially by screening test. These findings can provide valuable information for stakeholders on equipment needs when implementing a national screening program in Ukraine.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Humanos , Tamizaje Masivo , Sangre Oculta , Ucrania
10.
JAMA Netw Open ; 5(3): e221766, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35267034

RESUMEN

Importance: The association of surgeons' and hospitals' operative volumes with postoperative patient outcomes has been studied for decades and holds important policy implications; however, in many volume-outcome analyses, this association is described without the envisioning of a clear intervention, which often introduces unintentional bias. Acting on such results may lead to unintended consequences from policy interventions or patient recommendations. Objective: To specify how (hypothetical) target trials would be designed to estimate the association between postoperative mortality of patients undergoing operations and a range of surgeon and hospital volume conditions and then to emulate these trials by using observational data. Design, Setting, and Participants: This observational data analysis emulated 4 hypothetical target trials of increasing complexity, ranging from a poorly defined trial that would randomly assign participants only to surgeon volume to one that would randomly assign participants to surgeon volume, hospital volume, and specific surgeon and hospital. This population-based cohort study included 9136 Medicare beneficiaries with a first diagnosis of pancreatic malignant neoplasm who did not require neoadjuvant therapy and underwent pancreatectomy between January 1, 2012, and September 30, 2016. Data analysis was performed between September 1, 2019, and October 8, 2021. Exposures: Number of pancreatectomies performed by surgeon and hospital during the prior year. Main Outcomes and Measures: Ninety-day mortality. Results: The analyses included 9136 Medicare beneficiaries treated by 1358 surgeons at 697 hospitals; median age was 73.3 years (IQR, 69.1-78.1 years), and 4642 were men (51%). When trials with poorly defined interventions on surgeon volume were emulated, the estimated 90-day mortality was 7.9% (95% CI, 6.4%-9.4%) for lower-volume surgeons and 5.2% (95% CI, 2.7%-10.9%) for higher-volume surgeons. When trials with better-defined interventions were emulated, the difference was reduced: 7.8% (95% CI, 6.3%-9.3%) for lower-volume surgeons and 7.2% (95% CI, 6.0%-8.7%) for higher-volume surgeons. Conclusions and Relevance: In this cohort study that emulated 4 different target trials with data from Medicare beneficiaries undergoing pancreatectomy, mortality differences across surgical volume levels were attenuated when the interventions were well defined. The application of the hypothetical target trial framework to this specific volume-outcomes scenario revealed the complexities of this research question and the unintentional biases introduced in prior studies, which emulated poorly defined trials whose results are therefore difficult to interpret. The target trial framework may be of value to outcomes researchers asking questions that correspond to well-defined interventions for the real world.


Asunto(s)
Neoplasias Pancreáticas , Cirujanos , Anciano , Estudios de Cohortes , Femenino , Hospitales , Humanos , Masculino , Medicare , Pancreatectomía , Neoplasias Pancreáticas/cirugía , Estados Unidos/epidemiología
11.
Am J Epidemiol ; 190(11): 2453-2460, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34089045

RESUMEN

The number of operations that surgeons have previously performed is associated with their patients' outcomes. However, this association may not be causal, because previous studies have often been cross-sectional and their analyses have not considered time-varying confounding or positivity violations. In this paper, using the example of surgeons who perform coronary artery bypass grafting, we describe (hypothetical) target trials for estimation of the causal effect of the surgeons' operative volumes on patient mortality. We then demonstrate how to emulate these target trials using data from US Medicare claims and provide effect estimates. Our target trial emulations suggest that interventions on physicians' volume of coronary artery bypass grafting operations have little effect on patient mortality. The target trial framework highlights key assumptions and draws attention to areas of bias in previous observational analyses that deviated from their implicit target trials. The principles of the presented methodology may be adapted to other scenarios of substantive interest in health services research.


Asunto(s)
Puente de Arteria Coronaria/mortalidad , Métodos Epidemiológicos , Investigación sobre Servicios de Salud/métodos , Cirujanos/estadística & datos numéricos , Adulto , Anciano , Conjuntos de Datos como Asunto , Femenino , Humanos , Masculino , Medicare/estadística & datos numéricos , Persona de Mediana Edad , Estados Unidos/epidemiología
12.
Transpl Int ; 34(4): 648-656, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33527506

RESUMEN

There has been a recent increase in enthusiasm for expansion of living donor liver transplantation (LDLT) programmes. Using all adults initially placed on the waiting list in the United States, we estimated the risk of overall mortality under national strategies which differed in their utilization of LDLT. We used a generalization of inverse probability weighting which can estimate the effect of interventions in the setting of finite resources. From 2005 to 2015, 93 812 eligible individuals were added to the waitlist: 51 322 received deceased donor grafts while 1970 underwent LDLT. Individuals who underwent LDLT had more favourable prognostic factors, including lower mean MELD score at transplant (14.6 vs. 20.5). The 1-year, 5-year and 10-year cumulative incidence of death under the current level of LDLT utilization were 18.0% (95% CI: 17.8, 18.3%), 41.2% (95% CI: 40.8, 41.5%) and 57.4% (95% CI: 56.9, 57.9%) compared to 17.9% (95% CI: 17.7, 18.2%), 40.6% (95% CI: 40.2, 40.9%) and 56.4% (95% CI: 55.8, 56.9%) under a strategy which doubles LDLT utilization. Expansion of LDLT utilization would have a measurable, modest effect on the risk of mortality for the entire cohort of individuals who begin on the transplant waiting list.


Asunto(s)
Trasplante de Hígado , Adulto , Estudios de Cohortes , Humanos , Incidencia , Donadores Vivos , Estudios Retrospectivos , Resultado del Tratamiento , Estados Unidos , Listas de Espera
13.
J Vasc Surg ; 73(5): 1593-1602.e7, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32976969

RESUMEN

OBJECTIVE: Operative volume has been used as a marker of quality. Research from previous decades has suggested minimum open abdominal aortic aneurysm (AAA) repair volume requirements for surgeons of 9 to 13 open AAA repairs annually and for hospitals of 18 open AAA repairs annually to purportedly achieve acceptable results. Given concerns regarding the decreased frequency of open repairs in the endovascular era, we examined the association of surgeon and hospital volume with the 30- and 90-day mortality in the Vascular Quality Initiative (VQI) registry. METHODS: Patients who had undergone elective open AAA repair from 2013 to 2018 were identified in the VQI registry. We performed a cross-sectional evaluation of the association between the average hospital and surgeon volume and 30-day postoperative mortality using a hierarchical Bayesian model. Cross-level interactions were permitted, and random surgeon- and hospital-level intercepts were used to account for clustering. The mortality results were adjusted by standardizing to the observed distribution of relevant covariates in the overall cohort. The outcomes were compared to the Society for Vascular Surgery guidelines recommended criteria of <5% perioperative mortality. RESULTS: A total of 3078 patients had undergone elective open AAA repair by 520 surgeons at 128 hospitals. The 30- and 90-day risks of postoperative mortality were 4.1% (n = 126) and 5.4% (n = 166), respectively. The mean surgeon volume and hospital volume both correlated inversely with the 30-day mortality. Averaged across all patients and hospitals, we found a 96% probability that surgeons who performed an average of four or more repairs per year achieved <5% 30-day mortality. Substantial interplay was present between surgeon volume and hospital volume. For example, at lower volume hospitals performing an average of five repairs annually, <5% 30-day mortality would be expected 69% of the time for surgeons performing an average of three operations annually. In contrast, at higher volume hospitals performing an average of 40 repairs annually, a <5% 30-day mortality would be expected 96% of the time for surgeons performing an average of three operations annually. As hospital volume increased, a diminishing difference occurred in 30-day mortality between lower and higher volume surgeons. Likewise, as surgeon volume increased, a diminishing difference was found in 30-day mortality between the lower and higher volume hospitals. CONCLUSIONS: Surgeons and hospitals in the VQI registry achieved mortality outcomes of <5% (Society for Vascular Surgery guidelines), with an average surgeon volume that was substantially lower compared with previous reports. Furthermore, when considering the development of minimal surgeon volume guidelines, it is important to contextualize the outcomes within the hospital volumes.


Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular/mortalidad , Hospitales de Alto Volumen , Hospitales de Bajo Volumen , Cirujanos , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/mortalidad , Implantación de Prótesis Vascular/efectos adversos , Competencia Clínica , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos , Carga de Trabajo
14.
Clin Trials ; 17(5): 570-575, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32414298

RESUMEN

BACKGROUND: Clinicians and patients may be more interested in per-protocol effect estimates than intention-to-treat effect estimates from randomized trials. However, per-protocol effect estimates may be biased due to insufficient adjustment for prognostic factors that predict adherence. Adjustment for this bias is possible when appropriate methods, such as inverse probability weighting, are used. But, when adherence is measured as a continuous variable, constructing these weights can be challenging. METHODS: In the placebo arm of the Lipid Research Clinics Coronary Primary Prevention Trial, we estimated the 7-year cumulative incidence of coronary heart disease under 100% adherence and 0% adherence to placebo. We used dose-response discrete-hazards models with inverse probability weighting to adjust for pre- and post-randomization covariates. We considered several continuous distributions for constructing the inverse probability weights. RESULTS: The risk difference estimate for 100% adherence compared with 0% adherence ranged from -7.7 to -6.1 percentage points without adjustment for baseline and post-baseline covariates, and ranged from -1.8 to 2.2 percentage points with adjustment using inverse probability weights, depending on the dose-response model and inverse probability weight distribution used. CONCLUSIONS: Methods which appropriately adjust for time-varying post-randomization variables can explain away much of the bias in the "effect" of adherence to placebo. When considering continuous adherence, investigators should consider several models as estimates may be sensitive to the model chosen.


Asunto(s)
Resina de Colestiramina/uso terapéutico , Enfermedad Coronaria/epidemiología , Hipercolesterolemia/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Adulto , Anticolesterolemiantes/uso terapéutico , Sesgo , Enfermedad Coronaria/prevención & control , Humanos , Incidencia , Análisis de Intención de Tratar , Lípidos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Prevención Primaria , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos
15.
Epidemiology ; 31(3): 365-368, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32267654

RESUMEN

Partial exchangeability is sufficient for the identification of some causal effects of interest. Here we review the use of common graphical tools and the sufficient component cause model in the context of partial exchangeability. We illustrate the utility of single world intervention graphs (SWIGs) in depicting partial exchangeability and provide an illustrative example of when partial exchangeability might hold in the absence of complete exchangeability.


Asunto(s)
Causalidad , Gráficos por Computador , Humanos
16.
Ann Surg ; 272(6): 1149-1157, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-30601262

RESUMEN

OBJECTIVE: To describe variability in and consequences of opioid prescriptions following pediatric laparoscopic appendectomy. SUMMARY BACKGROUND DATA: Postoperative opioid prescribing patterns may contribute to persistent opioid use in both adults and children. METHODS: We included children <18 years enrolled as dependents in the Military Health System Data Repository who underwent uncomplicated laparoscopic appendectomy (2006-2014). For the primary outcome of days of opioids prescribed, we evaluated associations with discharging service, standardized to the distribution of baseline covariates. Secondary outcomes included refill, Emergency Department (ED) visit for constipation, and ED visit for pain. RESULTS: Among 6732 children, 68% were prescribed opioids (range = 1-65 d, median = 4 d, IQR = 3-5 d). Patients discharged by general surgery services were prescribed 1.23 (95% CI = 1.06-1.42) excess days of opioids, compared with those discharged by pediatric surgery services. Risk of ED visit for constipation (n = 61, 1%) was increased with opioid prescription [1-3 d, risk ratio (RR) = 2.46, 95% CI = 1.31-5.78; 4-6 d, RR = 1.89, 95% CI = 0.83-4.67; 7-14 d, RR = 3.75, 95% CI = 1.38-9.44; >14 d, RR = 6.27, 95% CI = 1.23-19.68], compared with no opioid prescription. There was similar or increased risk of ED visit for pain (n = 319, 5%) with opioid prescription [1-3 d, RR = 1.00, 95% confidence interval (CI) = 0.74-1.32; 4-6 d, RR = 1.31, 95% CI = 0.99-1.73; 7-14 d, RR = 1.52, 95% CI = 1.00-2.18], compared with no opioid prescription. Likewise, need for refill (n = 157, 3%) was not associated with initial days of opioid prescribed (reference 1-3 d; 4-6 d, RR = 0.96, 95% CI = 0.68-1.35; 7-14 d, RR = 0.91, 95% CI = 0.49-1.46; and >14 d, RR = 1.22, 95% CI = 0.59-2.07). CONCLUSIONS: There was substantial variation in opioid prescribing patterns. Opioid prescription duration increased risk of ED visits for constipation, but not for pain or refill.


Asunto(s)
Analgésicos Opioides/uso terapéutico , Apendicectomía/métodos , Prescripciones de Medicamentos/estadística & datos numéricos , Laparoscopía , Dolor Postoperatorio/tratamiento farmacológico , Pautas de la Práctica en Medicina , Adolescente , Analgésicos Opioides/efectos adversos , Niño , Preescolar , Estudios de Cohortes , Estreñimiento/inducido químicamente , Estreñimiento/epidemiología , Servicio de Urgencia en Hospital , Femenino , Humanos , Lactante , Masculino
17.
Eur J Epidemiol ; 34(3): 225-233, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30673924

RESUMEN

Causal inference for treatments with many versions requires a careful specification of the versions of treatment. Specifically, the existence of multiple relevant versions of treatment has implications for the selection of confounders. To illustrate this, we estimate the effect of organ transplantation using grafts from donors who died due to anoxic drug overdose, on recipient graft survival in the US. We describe how explicitly outlining the target trial (i.e. the hypothetical randomized trial which would answer the causal question of interest) to be emulated by an observational study analysis helps conceptualize treatment versions, guides selection of appropriate adjustment variables, and helps clarify the settings in which causal effects of compound treatments will be of value to decision-makers.


Asunto(s)
Factores de Confusión Epidemiológicos , Trasplante de Órganos/métodos , Adulto , Anciano , Sobredosis de Droga/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Donantes de Tejidos/estadística & datos numéricos , Resultado del Tratamiento , Estados Unidos/epidemiología
18.
Transplantation ; 103(5): 973-979, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30273236

RESUMEN

BACKGROUND: The opioid epidemic and the deaths of otherwise healthy individuals due to drug overdose in the United States has major implications for transplantation. The current extent and safety of utilization of liver and kidney grafts from donation after circulatory death (DCD) donors who died from opioid overdose is unknown. METHODS: Using national data from 2006 to 2016, we estimated the cumulative incidence of graft failure for recipients of DCD grafts, comparing the risk among recipients of organs from donors who died of anoxic drug overdose and recipients of organs from donors who died of other causes. RESULTS: One hundred seventy-nine (6.2%) of 2908 liver graft recipients and 944 (6.1%) of 15520 kidney graft recipients received grafts from donors who died of anoxic drug overdose. Grafts from anoxic drug overdose donors were less frequently used compared with other DCD grafts (liver, 25.9% versus 29.6%; 95% confidence interval [CI] for difference, -6.7% to -0.7%; kidney, 81.0% versus 84.7%; 95% CI for difference, -7.3% to -0.1%). However, the risk of graft failure at 5 years was similar for recipients of anoxic drug overdose donor grafts and recipients of other grafts (liver risk difference, 1.8%; 95% CI, -7.8% to 11.8%; kidney risk difference, -1.5%; 95% CI, -5.4% to 3.1%). CONCLUSIONS: In the context of the current opioid epidemic, utilization of anoxic drug overdose DCD donor grafts does not increase the risk of graft failure and may help to address waitlist demands.


Asunto(s)
Selección de Donante/estadística & datos numéricos , Sobredosis de Droga/mortalidad , Rechazo de Injerto/epidemiología , Trasplante de Riñón/estadística & datos numéricos , Trasplante de Hígado/estadística & datos numéricos , Adulto , Analgésicos Opioides/envenenamiento , Selección de Donante/normas , Sobredosis de Droga/etiología , Femenino , Rechazo de Injerto/etiología , Humanos , Trasplante de Riñón/efectos adversos , Trasplante de Hígado/efectos adversos , Masculino , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud/estadística & datos numéricos , Estudios Retrospectivos , Medición de Riesgo/estadística & datos numéricos , Factores de Riesgo , Donantes de Tejidos/estadística & datos numéricos , Estados Unidos/epidemiología , Listas de Espera , Adulto Joven
19.
J Trauma Acute Care Surg ; 86(3): 532-539, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30507857

RESUMEN

BACKGROUND: Junctional tourniquets have been incorporated into tactical combat casualty care for junctional vascular trauma. They apply external compression to stop blood flow in the groin and axilla. OBJECTIVES: The primary outcome was effectiveness in achieving arterial occlusion. Secondary outcomes included time to application and pain scores. DATA SOURCES: Medline and EMBASE databases were searched. STUDY APPRAISAL AND SYNTHESIS METHODS: A random-effects meta-analysis was conducted to estimate the average effectiveness and time to effective application for each device. RESULTS: Eight studies reported the effectiveness of junctional tourniquets in healthy volunteers. The average effectiveness was 52% (95% confidence interval [CI], 15-87%) for the abdominal application of the abdominal aortic and junctional tourniquet (AAJT), 83% (95% CI, 73-89%; 26%) for the junctional Emergency Treatment Tool, 87% (95% CI, 79-92%; 15%) for the SAM junctional tourniquet (SJT), and 95% (95% CI, 90-98%) for the Combat Ready Clamp. The groin application of the AAJT was studied in two articles with 100% in both studies. The average time to application was 101 seconds for the SAM junctional tourniquet (95% CI, 50-152 seconds) and the Combat Ready Clamp (95% CI, 63-139 seconds), while it was 130 seconds (95% CI, 85-176 seconds) for the Junctional Emergency Treatment Tool. The abdominal application of AAJT had an average time to application of 92 and 171 seconds in two studies. LIMITATIONS: All studies were conducted in healthy volunteers. CONCLUSION AND IMPLICATIONS: Junctional tourniquets may meet a medical need in combat, and in the civilian environment, to control hemorrhage from these difficult injuries. All four Food and Drug Administration-approved devices demonstrate the ability to achieve vascular occlusion in healthy volunteers; however, effectiveness in patient transport has not been evaluated, and outcomes of their use in the field need to be captured and reported. LEVEL OF EVIDENCE: Systematic review, level III.


Asunto(s)
Tratamiento de Urgencia , Voluntarios Sanos , Hemorragia/prevención & control , Torniquetes , Axila/irrigación sanguínea , Humanos , Arteria Ilíaca , Medicina Militar , Dimensión del Dolor
20.
Int J Colorectal Dis ; 33(11): 1525-1532, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29946860

RESUMEN

PURPOSE: The relationship between emergency colon cancer resection and long-term oncological outcomes is not well understood. Our objective was to characterize the impact of emergency resection for colon cancer on disease-free and overall patient survival. METHODS: Data on patients undergoing resection for colon cancer from 2006 to 2015 were collected from a prospectively maintained clinical and administrative database. The median follow-up time was 4.4 years. Cox proportional hazards models were used to estimate the hazard ratios for recurrence and death for patients treated with surgery for an emergent presentation. Differences in initiation of, and timeliness of, adjuvant chemotherapy between emergently and electively treated patients were also examined. RESULTS: Of the 1180 patients who underwent resection for stages I, II, or III colon cancer, 158 (13%) had emergent surgery. After adjustment for patient, tumor, and treatment characteristics, the HR for recurrence was 1.64 (95% CI 1.12-2.40) and for death was 1.47 (95% CI 1.10-1.97). After adjustment for tumor characteristics, patients who underwent emergency resection were similarly likely to receive adjuvant chemotherapy (OR 1.1; 95% CI 0.70-1.76). The time from surgery to initiation of adjuvant chemotherapy was also similar between the groups. CONCLUSIONS: Emergency surgery for localized or regional colon cancer is associated with a greater risk of recurrence and death. This association does not appear to be due to differences in adjuvant treatment. A focus on screening and colon cancer awareness in order to reduce emergency presentations is warranted.


Asunto(s)
Colectomía , Neoplasias del Colon/cirugía , Urgencias Médicas , Anciano , Neoplasias del Colon/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Modelos de Riesgos Proporcionales , Factores de Tiempo , Resultado del Tratamiento
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