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Xu C, Zhang F, Doi SAR, Furuya-Kanamori L, Lin L, Chu H, Yang X, Li S, Zorzela L, Golder S, Loke Y, Vohra S. Influence of lack of blinding on the estimation of medication-related harms: a retrospective cohort study of randomized controlled trials. BMC Med 2024; 22:83. [PMID: 38448992 PMCID: PMC10919027 DOI: 10.1186/s12916-024-03300-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/12/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND Empirical evidence suggests that lack of blinding may be associated with biased estimates of treatment benefit in randomized controlled trials, but the influence on medication-related harms is not well-recognized. We aimed to investigate the association between blinding and clinical trial estimates of medication-related harms. METHODS We searched PubMed from January 1, 2015, till January 1, 2020, for systematic reviews with meta-analyses of medication-related harms. Eligible meta-analyses must have contained trials both with and without blinding. Potential covariates that may confound effect estimates were addressed by restricting trials within the comparison or by hierarchical analysis of harmonized groups of meta-analyses (therefore harmonizing drug type, control, dosage, and registration status) across eligible meta-analyses. The weighted hierarchical linear regression was then used to estimate the differences in harm estimates (odds ratio, OR) between trials that lacked blinding and those that were blinded. The results were reported as the ratio of OR (ROR) with its 95% confidence interval (CI). RESULTS We identified 629 meta-analyses of harms with 10,069 trials. We estimated a weighted average ROR of 0.68 (95% CI: 0.53 to 0.88, P < 0.01) among 82 trials in 20 meta-analyses where blinding of participants was lacking. With regard to lack of blinding of healthcare providers or outcomes assessors, the RORs were 0.68 (95% CI: 0.53 to 0.87, P < 0.01 from 81 trials in 22 meta-analyses) and 1.00 (95% CI: 0.94 to 1.07, P = 0.94 from 858 trials among 155 meta-analyses) respectively. Sensitivity analyses indicate that these findings are applicable to both objective and subjective outcomes. CONCLUSIONS Lack of blinding of participants and health care providers in randomized controlled trials may underestimate medication-related harms. Adequate blinding in randomized trials, when feasible, may help safeguard against potential bias in estimating the effects of harms.
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Affiliation(s)
- Chang Xu
- Proof of Concept Center, Eastern Hepatobiliary Surgery Hospital, Third Affiliated Hospital, Second Military Medical University, Naval Medical University, Shanghai, China.
| | - Fengying Zhang
- Chinese Evidence-Based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Suhail A R Doi
- Department of Population Medicine, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Luis Furuya-Kanamori
- UQ Center for Clinical Research, The University of Queensland, Herston, Australia
| | - Lifeng Lin
- Department of Epidemiology and Biostatistics, University of Arizona, Tucson, AZ, USA
| | - Haitao Chu
- Statistical Research and Innovation, Global Biometrics and Data Management, Pfizer Inc, New York, NY, USA
- Division of Biostatistics and Health Data Science, University of Minnesota School of Public Health, Minneapolis, MN, USA
| | - Xi Yang
- Proof of Concept Center, Eastern Hepatobiliary Surgery Hospital, Third Affiliated Hospital, Second Military Medical University, Naval Medical University, Shanghai, China
| | - Sheyu Li
- Department of Endocrinology and Metabolism, MAGIC China Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Liliane Zorzela
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Su Golder
- Department of Health Sciences, University of York, York, UK
| | - Yoon Loke
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Sunita Vohra
- Departments of Pediatrics & Psychiatry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
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Teichert F, Karner V, Döding R, Saueressig T, Owen PJ, Belavy DL. Effectiveness of Exercise Interventions for Preventing Neck Pain: A Systematic Review With Meta-analysis of Randomized Controlled Trials. J Orthop Sports Phys Ther 2023; 53:594–609. [PMID: 37683100 DOI: 10.2519/jospt.2023.12063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
OBJECTIVE: To update the evidence on the effectiveness of exercise interventions to prevent episodes of neck pain. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: MEDLINE, Embase, CENTRAL, CINAHL, SPORTDiscus, PEDro, and trial registries from inception to December 2, 2022. Forward and backward citation searches. STUDY SELECTION CRITERIA: Randomized controlled trials (RCTs) that enrolled adults without neck pain at baseline and compared exercise interventions to no intervention, placebo/sham, attention control, or minimal intervention. Military populations and astronauts were excluded. DATA SYNTHESIS: Random-effects meta-analysis. Risk of bias was assessed using the Cochrane RoB 2 tool. The certainty of evidence was judged according to the GRADE approach. RESULTS: Of 4703 records screened, 5 trials (1722 participants at baseline) were included and eligible for meta-analysis. Most (80%) participants were office workers. Risk of bias was rated as some concerns for 2 trials and high for 3 trials. There was moderate-certainty evidence that exercise interventions probably reduce the risk of a new episode of neck pain (OR, 0.49; 95% confidence interval: 0.31, 0.76) compared to no or minimal intervention in the short-term (≤12 months). The results were not robust to sensitivity analyses for missing outcome data. CONCLUSION: There was moderate-certainty evidence supporting exercise interventions for reducing the risk for an episode of neck pain in the next 12 months. The clinical significance of the effect is unclear. J Orthop Sports Phys Ther 2023;53(10):1-16. Epub: 8 September 2023. doi:10.2519/jospt.2023.12063.
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Affiliation(s)
- Florian Teichert
- Division of Physiotherapy, Department of Applied Health Sciences, Hochschule für Gesundheit (University of Applied Sciences), Bochum, Germany
| | - Vera Karner
- Division of Physiotherapy, Department of Applied Health Sciences, Hochschule für Gesundheit (University of Applied Sciences), Bochum, Germany
| | - Rebekka Döding
- Division of Physiotherapy, Department of Applied Health Sciences, Hochschule für Gesundheit (University of Applied Sciences), Bochum, Germany
| | | | - Patrick J Owen
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Daniel L Belavy
- Division of Physiotherapy, Department of Applied Health Sciences, Hochschule für Gesundheit (University of Applied Sciences), Bochum, Germany
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Tan ALM, Getzen EJ, Hutch MR, Strasser ZH, Gutiérrez-Sacristán A, Le TT, Dagliati A, Morris M, Hanauer DA, Moal B, Bonzel CL, Yuan W, Chiudinelli L, Das P, Zhang HG, Aronow BJ, Avillach P, Brat GA, Cai T, Hong C, La Cava WG, Hooi Will Loh H, Luo Y, Murphy SN, Yuan Hgiam K, Omenn GS, Patel LP, Jebathilagam Samayamuthu M, Shriver ER, Shakeri Hossein Abad Z, Tan BWL, Visweswaran S, Wang X, Weber GM, Xia Z, Verdy B, Long Q, Mowery DL, Holmes JH. Informative missingness: What can we learn from patterns in missing laboratory data in the electronic health record? J Biomed Inform 2023; 139:104306. [PMID: 36738870 PMCID: PMC10849195 DOI: 10.1016/j.jbi.2023.104306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 01/21/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
BACKGROUND In electronic health records, patterns of missing laboratory test results could capture patients' course of disease as well as reflect clinician's concerns or worries for possible conditions. These patterns are often understudied and overlooked. This study aims to identify informative patterns of missingness among laboratory data collected across 15 healthcare system sites in three countries for COVID-19 inpatients. METHODS We collected and analyzed demographic, diagnosis, and laboratory data for 69,939 patients with positive COVID-19 PCR tests across three countries from 1 January 2020 through 30 September 2021. We analyzed missing laboratory measurements across sites, missingness stratification by demographic variables, temporal trends of missingness, correlations between labs based on missingness indicators over time, and clustering of groups of labs based on their missingness/ordering pattern. RESULTS With these analyses, we identified mapping issues faced in seven out of 15 sites. We also identified nuances in data collection and variable definition for the various sites. Temporal trend analyses may support the use of laboratory test result missingness patterns in identifying severe COVID-19 patients. Lastly, using missingness patterns, we determined relationships between various labs that reflect clinical behaviors. CONCLUSION In this work, we use computational approaches to relate missingness patterns to hospital treatment capacity and highlight the heterogeneity of looking at COVID-19 over time and at multiple sites, where there might be different phases, policies, etc. Changes in missingness could suggest a change in a patient's condition, and patterns of missingness among laboratory measurements could potentially identify clinical outcomes. This allows sites to consider missing data as informative to analyses and help researchers identify which sites are better poised to study particular questions.
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Affiliation(s)
| | - Emily J Getzen
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | | | | | - Trang T Le
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | | | | | | | | | | | | | - Priam Das
- Harvard Medical School, Cambridge, MA, USA
| | | | - Bruce J Aronow
- Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, USA
| | | | | | - Tianxi Cai
- Harvard Medical School, Cambridge, MA, USA
| | - Chuan Hong
- Harvard Medical School, Cambridge, MA, USA; Duke University, Durham, NC, USA
| | - William G La Cava
- Harvard Medical School, Cambridge, MA, USA; Boston Children's Hospital, Boston, MA, USA
| | | | - Yuan Luo
- Northwestern University, Chicago, IL, USA
| | | | | | | | - Lav P Patel
- University of Kansas Medical Center, United States
| | | | - Emily R Shriver
- University of Pennsylvania Health System, Philadelphia, PA, USA
| | | | | | | | - Xuan Wang
- Harvard Medical School, Cambridge, MA, USA
| | | | - Zongqi Xia
- University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Qi Long
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Danielle L Mowery
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - John H Holmes
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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4
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Keyes-Elstein L, Pinckney A, Goldmuntz E, Welch B, Franks JM, Martyanov V, Wood TA, Crofford L, Mayes M, McSweeney P, Nash R, Georges G, Csuka M, Simms R, Furst D, Khanna D, St Clair EW, Whitfield ML, Sullivan KM. Clinical and Molecular Findings After Autologous Stem Cell Transplantation or Cyclophosphamide for Scleroderma: Handling Missing Longitudinal Data. Arthritis Care Res (Hoboken) 2023; 75:307-316. [PMID: 34533286 PMCID: PMC8926930 DOI: 10.1002/acr.24785] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/23/2021] [Accepted: 09/14/2021] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Among individuals with systemic sclerosis (SSc) randomized to cyclophosphamide (CYC) (n = 34) or hematopoietic stem cell transplantation (HSCT) (n = 33), we examined longitudinal trends of clinical, pulmonary function, and quality of life measures while accounting for the influence of early failures on treatment comparisons. METHODS Assuming that data were missing at random, mixed-effects regression models were used to estimate longitudinal trends for clinical measures when comparing treatment groups. Results were compared to observed means and to longitudinal trends estimated from shared parameter models, assuming that data were missing not at random. Longitudinal trends for SSc intrinsic molecular subsets defined by baseline gene expression signatures (normal-like, inflammatory, and fibroproliferative signatures) were also studied. RESULTS Available observed means for pulmonary function tests appeared to improve over time in both arms. However, after accounting for participant loss, forced vital capacity in HSCT recipients increased by 0.77 percentage points/year but worsened by -3.70/year for CYC (P = 0.004). Similar results were found for diffusing capacity for carbon monoxide and quality of life indicators. Results for both analytic models were consistent. HSCT recipients in the inflammatory (n = 20) and fibroproliferative (n = 20) subsets had superior long-term trends compared to CYC for pulmonary and quality of life measures. HSCT was also superior for modified Rodnan skin thickness scores in the fibroproliferative subset. For the normal-like subset (n = 22), superiority of HSCT was less apparent. CONCLUSION Longitudinal trends estimated from 2 statistical models affirm the efficacy of HSCT over CYC in severe SSc. Failure to account for early loss of participants may distort estimated clinical trends over the long term.
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Affiliation(s)
| | | | - Ellen Goldmuntz
- National Institute of Allergy and Infectious Diseases, Bethesda, MD
| | - Beverly Welch
- National Institute of Allergy and Infectious Diseases, Bethesda, MD
| | | | | | | | - Leslie Crofford
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Maureen Mayes
- University of Texas McGovern Medical School, Houston, TX
| | | | | | | | - M.E. Csuka
- Medical College of Wisconsin, Milwaukee, WI
| | - Robert Simms
- Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Daniel Furst
- University of California Los Angeles, Los Angeles, CA; University of Washington, Seattle, WA; University of Florence, Florence, Italy
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Garg R. Methodological survey of missing outcome data in an alteplase for ischemic stroke meta-analysis. Acta Neurol Scand 2022; 146:252-257. [PMID: 35652287 PMCID: PMC9541760 DOI: 10.1111/ane.13656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/29/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Recent national guidelines recommend alteplase treatment for ischemic stroke within 4.5 h of symptom-onset based on meta-analyses of randomized controlled clinical trials (RCT). A detailed description of missing outcome data (MOD) due to participant loss to follow-up has never been published. The objective of this study was to perform a methodlogical survey on missing outcome data in an alteplase for ischemic stroke meta-analysis. MATERIALS AND METHODS A methodological survey was performed on a chosen meta-analysis of alteplase for ischemic stroke RCTs that most closely aligns with recent national guideline recommendations. Data were collected to assess the number of participants lost to follow-up; differential lost to follow-up between allocation groups; baseline characteristics of those lost to follow-up; and the imputation methods used by individual trials and the chosen meta-analysis. The number of participants lost to follow-up was compared with the fragility index; and repeated for individually positive RCTs in the meta-analysis. RESULTS The methodological survey revealed a substantial degree of missing information regarding MOD in the chosen meta-analysis and in individual RCTs. Single imputation was exclusively used in all RCTs and in the meta-analysis. The number of participants lost to follow-up was greater than the fragility index in the chosen meta-analysis and individually positive component RCTs suggesting that MOD may impact the direction of the reported effect or effect size. CONCLUSION This methodological survey of an alteplase for ischemic stroke meta-analysis revealed MOD may be an important source of unrecognized bias. This survey highlights the need for sensitivity analyses using more robust methods of imputation.
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Affiliation(s)
- Ravi Garg
- Division of Neurocritical Care, Department of Neurology Loyola University Chicago Stritch School of Medicine Maywood Illinois USA
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6
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Xu C, Yu T, Furuya-Kanamori L, Lin L, Zorzela L, Zhou X, Dai H, Loke Y, Vohra S. Validity of data extraction in evidence synthesis practice of adverse events: reproducibility study. BMJ 2022; 377:e069155. [PMID: 35537752 PMCID: PMC9086856 DOI: 10.1136/bmj-2021-069155] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/10/2022] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To investigate the validity of data extraction in systematic reviews of adverse events, the effect of data extraction errors on the results, and to develop a classification framework for data extraction errors to support further methodological research. DESIGN Reproducibility study. DATA SOURCES PubMed was searched for eligible systematic reviews published between 1 January 2015 and 1 January 2020. Metadata from the randomised controlled trials were extracted from the systematic reviews by four authors. The original data sources (eg, full text and ClinicalTrials.gov) were then referred to by the same authors to reproduce the data used in these meta-analyses. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Systematic reviews were included when based on randomised controlled trials for healthcare interventions that reported safety as the exclusive outcome, with at least one pair meta-analysis that included five or more randomised controlled trials and with a 2×2 table of data for event counts and sample sizes in intervention and control arms available for each trial in the meta-analysis. MAIN OUTCOME MEASURES The primary outcome was data extraction errors summarised at three levels: study level, meta-analysis level, and systematic review level. The potential effect of such errors on the results was further investigated. RESULTS 201 systematic reviews and 829 pairwise meta-analyses involving 10 386 randomised controlled trials were included. Data extraction could not be reproduced in 1762 (17.0%) of 10 386 trials. In 554 (66.8%) of 829 meta-analyses, at least one randomised controlled trial had data extraction errors; 171 (85.1%) of 201 systematic reviews had at least one meta-analysis with data extraction errors. The most common types of data extraction errors were numerical errors (49.2%, 867/1762) and ambiguous errors (29.9%, 526/1762), mainly caused by ambiguous definitions of the outcomes. These categories were followed by three others: zero assumption errors, misidentification, and mismatching errors. The impact of these errors were analysed on 288 meta-analyses. Data extraction errors led to 10 (3.5%) of 288 meta-analyses changing the direction of the effect and 19 (6.6%) of 288 meta-analyses changing the significance of the P value. Meta-analyses that had two or more different types of errors were more susceptible to these changes than those with only one type of error (for moderate changes, 11 (28.2%) of 39 v 26 (10.4%) 249, P=0.002; for large changes, 5 (12.8%) of 39 v 8 (3.2%) of 249, P=0.01). CONCLUSION Systematic reviews of adverse events potentially have serious issues in terms of the reproducibility of the data extraction, and these errors can mislead the conclusions. Implementation guidelines are urgently required to help authors of future systematic reviews improve the validity of data extraction.
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Affiliation(s)
- Chang Xu
- Key Laboratory of Population Health Across-life Cycle, Ministry of Education of the People's Republic of China, Anhui Medical University, Anhui, China
- Anhui Provincial Key Laboratory of Population Health and Aristogenics, Anhui Medical University, Anhui, China
- School of Public Health, Anhui Medical University, Anhui, China
| | - Tianqi Yu
- Chinese Evidence-based Medicine Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Luis Furuya-Kanamori
- UQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Lifeng Lin
- Department of Statistics, Florida State University, Tallahassee, FL, USA
| | - Liliane Zorzela
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, AB, Canada
| | - Xiaoqin Zhou
- Mental Health Centre, West China Hospital of Sichuan University, Chengdu, China
| | - Hanming Dai
- Mental Health Centre, West China Hospital of Sichuan University, Chengdu, China
| | - Yoon Loke
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Sunita Vohra
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, AB, Canada
- Departments of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, AB, Canada
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7
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Spineli LM, Kalyvas C, Papadimitropoulou K. How robust are findings of pairwise and network meta-analysis in the presence of missing participant outcome data? BMC Med 2021; 19:323. [PMID: 34930276 PMCID: PMC8691029 DOI: 10.1186/s12916-021-02195-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/22/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To investigate the prevalence of robust conclusions in systematic reviews addressing missing (participant) outcome data via a novel framework of sensitivity analyses and examine the agreement with the current sensitivity analysis standards. METHODS We performed an empirical study on systematic reviews with two or more interventions. Pairwise meta-analyses (PMA) and network meta-analyses (NMA) were identified from empirical studies on the reporting and handling of missing outcome data in systematic reviews. PMAs with at least three studies and NMAs with at least three interventions on one primary outcome were considered eligible. We applied Bayesian methods to obtain the summary effect estimates whilst modelling missing outcome data under the missing-at-random assumption and different assumptions about the missingness mechanism in the compared interventions. The odds ratio in the logarithmic scale was considered for the binary outcomes and the standardised mean difference for the continuous outcomes. We calculated the proportion of primary analyses with robust and frail conclusions, quantified by our proposed metric, the robustness index (RI), and current sensitivity analysis standards. Cohen's kappa statistic was used to measure the agreement between the conclusions derived by the RI and the current sensitivity analysis standards. RESULTS One hundred eight PMAs and 34 NMAs were considered. When studies with a substantial number of missing outcome data dominated the analyses, the number of frail conclusions increased. The RI indicated that 59% of the analyses failed to demonstrate robustness compared to 39% when the current sensitivity analysis standards were employed. Comparing the RI with the current sensitivity analysis standards revealed that two in five analyses yielded contradictory conclusions concerning the robustness of the primary analysis results. CONCLUSIONS Compared with the current sensitivity analysis standards, the RI offers an explicit definition of similar results and does not unduly rely on statistical significance. Hence, it may safeguard against possible spurious conclusions regarding the robustness of the primary analysis results.
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Affiliation(s)
- Loukia M Spineli
- Midwifery Research and Education Unit, Hannover Medical School, Hannover, Germany.
| | - Chrysostomos Kalyvas
- Biostatistics and Research Decision Sciences, MSD Europe Inc., Brussels, Belgium
| | - Katerina Papadimitropoulou
- Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.,Data Science and Biometrics, Danone Nutricia Research, Utrecht, The Netherlands
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8
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Harris RG, Batterham M, Neale EP, Ferreira I. Impact of missing outcome data in meta-analyses of lifestyle interventions during pregnancy to reduce postpartum weight retention: An overview of systematic reviews with meta-analyses and additional sensitivity analyses. Obes Rev 2021; 22:e13318. [PMID: 34477276 DOI: 10.1111/obr.13318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/20/2021] [Accepted: 06/22/2021] [Indexed: 12/01/2022]
Abstract
High risk of bias associated with missing outcome data (MOD) in meta-analyses (MAs) of the effects of lifestyle interventions during pregnancy on postpartum weight retention (PPWR) casts doubt on whether such interventions can be relied upon as truly effective. This systematic overview of three MAs (19 RCTs), each with high MOD rates in the subset of RCTs included, examined how MOD were addressed in the estimation of summary intervention effects. All MAs reported beneficial and statistically significant intervention effects estimated based on complete case analyses, deemed valid if MOD was missing at random (MAR). Therefore, we conducted sensitivity analyses using pattern mixture models and informative missingness parameters (describing how the outcome in the missing participants may be related to the outcome in the completers), to ascertain the robustness of the estimates to reasonable deviations from the MAR assumption. In plausible scenarios where the response in intervention group participants with versus without MOD was worse (by just 0.5 kg), effect estimates were attenuated in all MAs and no longer statistically significant in two MAs. Statistical significance was retained when all 19 RCTs identified across MAs were examined together in a broader meta-analysis: -0.63 kg (95%CI -0.17, -0.08), but the clinical relevancy of effects of this magnitude remains unclear.
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Affiliation(s)
- Rebecca G Harris
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia
| | - Marijka Batterham
- School of Mathematics and Applied Statistics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Elizabeth P Neale
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia
| | - Isabel Ferreira
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.,Public Health Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
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9
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Kahale LA, Matar CF, Tsolakian I, Hakoum MB, Barba M, Yosuico VE, Terrenato I, Sperati F, Schünemann H, Akl EA. Oral anticoagulation in people with cancer who have no therapeutic or prophylactic indication for anticoagulation. Cochrane Database Syst Rev 2021; 10:CD006466. [PMID: 34622445 PMCID: PMC8498286 DOI: 10.1002/14651858.cd006466.pub7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Oral anticoagulants may improve the survival of people with cancer through an antithrombotic effect, yet increase the risk of bleeding. OBJECTIVES To evaluate the efficacy and safety of oral anticoagulants in ambulatory people with cancer undergoing chemotherapy, targeted therapy, immunotherapy, or radiotherapy (either alone or in combination), with no standard therapeutic or prophylactic indication for anticoagulation. SEARCH METHODS We conducted comprehensive searches on 14 June 2021, following the original electronic searches performed in February 2016 (last major search). We electronically searched the following databases: CENTRAL, MEDLINE, Embase. In addition, we handsearched conference proceedings, checked references of included studies, and searched for ongoing studies. As part of the living systematic review approach, we are running continual searches and will incorporate new evidence rapidly after it is identified. SELECTION CRITERIA We included randomised controlled trials (RCTs) assessing the benefits and harms of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) in ambulatory people with cancer (i.e., not hospital inpatients during the time of their participation in trials) These people are typically undergoing systemic anticancer therapy, possibly including chemotherapy, targeted therapy, immunotherapy, or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation. DATA COLLECTION AND ANALYSIS Using a standardised form, two review authors independently extracted data on study design, participants, intervention outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, pulmonary embolism, symptomatic deep vein thrombosis (DVT), major bleeding, minor bleeding and health-related quality of life. We assessed the certainty of evidence for each outcome using the GRADE approach. MAIN RESULTS Of 12,620 identified citations, 10 RCTs fulfilled the inclusion criteria. The oral anticoagulant was a vitamin K antagonist (VKA) in six of these RCTs, and a direct oral anticoagulant (DOAC) in the remaining four RCTs (three studies used apixaban; one used rivaroxaban). The comparator was either placebo or no prophylaxis. Compared to no prophylaxis, vitamin K antagonists (VKAs) probably reduce mortality at six months slightly (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.77 to 1.13; risk difference (RD) 22 fewer per 1000, 95% CI 72 fewer to 41 more; moderate-certainty evidence), and probably reduce mortality at 12 months slightly (RR 0.95, 95% CI 0.87 to 1.03; RD 29 fewer per 1000, 95% CI 75 fewer to 17 more; moderate-certainty evidence). One study assessed the effect of a VKA compared to no prophylaxis on thrombosis; the evidence was very uncertain about the effect of VKA compared to no VKA on pulmonary embolism and symptomatic DVT (RR 1.05, 95% CI 0.07 to 16.58; RD 0 fewer per 1000, 95% CI 6 fewer to 98 more; very low-certainty evidence; RR 0.08, 95% CI 0.01 to 1.42; RD 35 fewer per 1000, 95% CI 37 fewer to 16 more; very low-certainty evidence, respectively). Also, VKAs probably increase major and minor bleeding at 12 months (RR 2.93, 95% CI 1.86 to 4.62; RD 107 more per 1000, 95% CI 48 more to 201 more; moderate-certainty evidence for major bleeding, and RR 3.14, 95% CI 1.85 to 5.32; RD 167 more per 1000, 95% CI 66 more to 337 more; moderate-certainty evidence for minor bleeding). Compared to no prophylaxis, at three to six months, direct oral anticoagulants (DOACs) probably reduce mortality slightly (RR 0.94, 95% CI 0.64 to 1.38, RD 11 fewer per 1000, 95% CI 67 fewer to 70 more; moderate-certainty evidence), probably reduce the risk of pulmonary embolism slightly compared to no prophylaxis (RR 0.48, 95% CI 0.24 to 0.98; RD 24 fewer per 1000, 95% CI 35 fewer to 1 fewer; moderate-certainty evidence), probably reduce symptomatic DVT slightly (RR 0.58, 95% CI 0.30 to 1.15; RD 21 fewer per 1000, 95% CI 35 fewer to 8 more; moderate-certainty evidence), probably do not increase major bleeding (RR 1.65, 95% CI 0.72 to 3.80; RD 9 more per 1000, 95% CI 4 fewer to 40 more; moderate-certainty evidence), and may increase minor bleeding (RR 3.58, 95% CI 0.55 to 23.44; RD 55 more per 1000, 95% CI 10 fewer to 482 more; low-certainty evidence). AUTHORS' CONCLUSIONS In ambulatory people with cancer undergoing chemotherapy, targeted therapy, immunotherapy, or radiotherapy (either alone or in combination), the current evidence on VKA thromboprophylaxis suggests that the harm of major bleeding might outweigh the benefit of reduction in venous thromboembolism. With DOACs, the benefit of reduction in venous thromboembolic events outweighs the risk of major bleeding. Editorial note: this is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence, as it becomes available. Please refer to the 'What's new' section in the Cochrane Database of Systematic Reviews for the current status of this review.
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Affiliation(s)
- Lara A Kahale
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Charbel F Matar
- Department of Internal Medicine, University of Connecticut, Hartford, Connecticut, USA
| | | | - Maram B Hakoum
- Family Medicine, American University of Beirut, Beirut, Lebanon
| | - Maddalena Barba
- Division of Medical Oncology 2 - Scientific Direction, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | | | - Irene Terrenato
- Biostatistics-Scientific Direction, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Francesca Sperati
- Biostatistics-Scientific Direction, Regina Elena National Cancer Institute, Rome, Italy
| | - Holger Schünemann
- Departments of Health Research Methods, Evidence, and Impact and of Medicine, McMaster University, Hamilton, Canada
| | - Elie A Akl
- Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
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Kahale LA, Matar CF, Tsolakian I, Hakoum MB, Yosuico VE, Terrenato I, Sperati F, Barba M, Hicks LK, Schünemann H, Akl EA. Antithrombotic therapy for ambulatory patients with multiple myeloma receiving immunomodulatory agents. Cochrane Database Syst Rev 2021; 9:CD014739. [PMID: 34582035 PMCID: PMC8477647 DOI: 10.1002/14651858.cd014739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Multiple myeloma is a malignant plasma cell disorder characterised by clonal plasma cells that cause end-organ damage such as renal failure, lytic bone lesions, hypercalcaemia and/or anaemia. People with multiple myeloma are treated with immunomodulatory agents including lenalidomide, pomalidomide, and thalidomide. Multiple myeloma is associated with an increased risk of thromboembolism, which appears to be further increased in people receiving immunomodulatory agents. OBJECTIVES (1) To systematically review the evidence for the relative efficacy and safety of aspirin, oral anticoagulants, or parenteral anticoagulants in ambulatory patients with multiple myeloma receiving immunomodulatory agents who otherwise have no standard therapeutic or prophylactic indication for anticoagulation. (2) To maintain this review as a living systematic review by continually running the searches and incorporating newly identified studies. SEARCH METHODS We conducted a comprehensive literature search that included (1) a major electronic search (14 June 2021) of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE via Ovid, and Embase via Ovid; (2) hand-searching of conference proceedings; (3) checking of reference lists of included studies; and (4) a search for ongoing studies in trial registries. As part of the living systematic review approach, we are running continual searches, and we will incorporate new evidence rapidly after it is identified. SELECTION CRITERIA Randomised controlled trials (RCTs) assessing the benefits and harms of oral anticoagulants such as vitamin K antagonist (VKA) and direct oral anticoagulants (DOAC), anti-platelet agents such as aspirin (ASA), and parenteral anticoagulants such as low molecular weight heparin (LMWH)in ambulatory patients with multiple myeloma receiving immunomodulatory agents. DATA COLLECTION AND ANALYSIS Using a standardised form, we extracted data in duplicate on study design, participants, interventions, outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), major bleeding, and minor bleeding. For each outcome we calculated the risk ratio (RR) with its 95% confidence interval (CI) and the risk difference (RD) with its 95% CI. We then assessed the certainty of evidence at the outcome level following the GRADE approach (GRADE Handbook). MAIN RESULTS We identified 1015 identified citations and included 11 articles reporting four RCTs that enrolled 1042 participants. The included studies made the following comparisons: ASA versus VKA (one study); ASA versus LMWH (two studies); VKA versus LMWH (one study); and ASA versus DOAC (two studies, one of which was an abstract). ASA versus VKA One RCT compared ASA to VKA at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 3.00, 95% CI 0.12 to 73.24; RD 2 more per 1000, 95% CI 1 fewer to 72 more; very low-certainty evidence); symptomatic DVT (RR 0.57, 95% CI 0.24 to 1.33; RD 27 fewer per 1000, 95% CI 48 fewer to 21 more; very low-certainty evidence); PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence); major bleeding (RR 7.00, 95% CI 0.36 to 134.72; RD 6 more per 1000, 95% CI 1 fewer to 134 more; very low-certainty evidence); and minor bleeding (RR 6.00, 95% CI 0.73 to 49.43; RD 23 more per 1000, 95% CI 1 fewer to 220 more; very low-certainty evidence). One RCT compared ASA to VKA at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to VKA on all-cause mortality (RR 0.50, 95% CI 0.05 to 5.47; RD 5 fewer per 1000, 95% CI 9 fewer to 41 more; very low-certainty evidence); symptomatic DVT (RR 0.71, 95% CI 0.35 to 1.44; RD 22 fewer per 1000, 95% CI 50 fewer to 34 more; very low-certainty evidence); and PE (RR 1.00, 95% CI 0.25 to 3.95; RD 0 fewer per 1000, 95% CI 14 fewer to 54 more; very low-certainty evidence). ASA versus LMWH Two RCTs compared ASA to LMWH at six months follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.81; RD 0 fewer per 1000, 95% CI 2 fewer to 38 more; very low-certainty evidence); symptomatic DVT (RR 1.23, 95% CI 0.49 to 3.08; RD 5 more per 1000, 95% CI 11 fewer to 43 more; very low-certainty evidence); PE (RR 7.71, 95% CI 0.97 to 61.44; RD 7 more per 1000, 95% CI 0 fewer to 60 more; very low-certainty evidence); major bleeding (RR 6.97, 95% CI 0.36 to 134.11; RD 6 more per 1000, 95% CI 1 fewer to 133 more; very low-certainty evidence); and minor bleeding (RR 1.42, 95% CI 0.35 to 5.78; RD 4 more per 1000, 95% CI 7 fewer to 50 more; very low-certainty evidence). One RCT compared ASA to LMWH at two years follow-up. The pooled data did not confirm or exclude a beneficial or detrimental effect of ASA relative to LMWH on all-cause mortality (RR 1.00, 95% CI 0.06 to 15.89; RD 0 fewer per 1000, 95% CI 4 fewer to 68 more; very low-certainty evidence); symptomatic DVT (RR 1.20, 95% CI 0.53 to 2.72; RD 9 more per 1000, 95% CI 21 fewer to 78 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). VKA versus LMWH One RCT compared VKA to LMWH at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 0.33, 95% CI 0.01 to 8.10; RD 3 fewer per 1000, 95% CI 5 fewer to 32 more; very low-certainty evidence); symptomatic DVT (RR 2.32, 95% CI 0.91 to 5.93; RD 36 more per 1000, 95% CI 2 fewer to 135 more; very low-certainty evidence); PE (RR 8.96, 95% CI 0.49 to 165.42; RD 8 more per 1000, 95% CI 1 fewer to 164 more; very low-certainty evidence); and minor bleeding (RR 0.33, 95% CI 0.03 to 3.17; RD 9 fewer per 1000, 95% CI 13 fewer to 30 more; very low-certainty evidence). The study reported that no major bleeding occurred in either arm. One RCT compared VKA to LMWH at two years follow-up. The data did not confirm or exclude a beneficial or detrimental effect of VKA relative to LMWH on all-cause mortality (RR 2.00, 95% CI 0.18 to 21.90; RD 5 more per 1000, 95% CI 4 fewer to 95 more; very low-certainty evidence); symptomatic DVT (RR 1.70, 95% CI 0.80 to 3.63; RD 32 more per 1000, 95% CI 9 fewer to 120 more; very low-certainty evidence); and PE (RR 9.00, 95% CI 0.49 to 166.17; RD 8 more per 1000, 95% CI 1 fewer to 165 more; very low-certainty evidence). ASA versus DOAC One RCT compared ASA to DOAC at six months follow-up. The data did not confirm or exclude a beneficial or detrimental effect of ASA relative to DOAC on DVT, PE, and major bleeding and minor bleeding (minor bleeding: RR 5.00, 95% CI 0.31 to 79.94; RD 4 more per 1000, 95% CI 1 fewer to 79 more; very low-certainty evidence). The study reported that no DVT, PE, or major bleeding events occurred in either arm. These results did not change in a meta-analysis including the study published as an abstract. AUTHORS' CONCLUSIONS The certainty of the available evidence for the comparative effects of ASA, VKA, LMWH, and DOAC on all-cause mortality, DVT, PE, or bleeding was either low or very low. People with multiple myeloma considering antithrombotic agents should balance the possible benefits of reduced thromboembolic complications with the possible harms and burden of anticoagulants. Editorial note: This is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.
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Affiliation(s)
- Lara A Kahale
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Charbel F Matar
- Department of Internal Medicine, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Ibrahim Tsolakian
- Department of Obstertrics and Gynaecology, University of Toledo College of Medicine and Life Sciences, Ohio, USA
| | - Maram B Hakoum
- Department of Family Medicine, Cornerstone Care Teaching Health Center, Mount Morris, Pennsylvania, USA
| | | | - Irene Terrenato
- Scientific Direction, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Francesca Sperati
- Scientific Direction, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Maddalena Barba
- Scientific Direction, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Lisa K Hicks
- Medicine, St. Michael's Hospital and the University of Toronto, Toronto, Canada
| | - Holger Schünemann
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Elie A Akl
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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Xu C, Zhou X, Zorzela L, Ju K, Furuya-Kanamori L, Lin L, Lu C, Musa OAH, Vohra S. Utilization of the evidence from studies with no events in meta-analyses of adverse events: an empirical investigation. BMC Med 2021; 19:141. [PMID: 34126999 PMCID: PMC8204528 DOI: 10.1186/s12916-021-02008-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/17/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUNDS Zero-events studies frequently occur in systematic reviews of adverse events, which consist of an important source of evidence. We aimed to examine how evidence of zero-events studies was utilized in the meta-analyses of systematic reviews of adverse events. METHODS We conducted a survey of systematic reviews published in two periods: January 1, 2015, to January 1, 2020, and January 1, 2008, to April 25, 2011. Databases were searched for systematic reviews that conducted at least one meta-analysis of any healthcare intervention and used adverse events as the exclusive outcome. An adverse event was defined as any untoward medical occurrence in a patient or subject in healthcare practice. We summarized the frequency of occurrence of zero-events studies in eligible systematic reviews and how these studies were dealt with in the meta-analyses of these systematic reviews. RESULTS We included 640 eligible systematic reviews. There were 406 (63.45%) systematic reviews involving zero-events studies in their meta-analyses, among which 389 (95.11%) involved single-arm-zero-events studies and 223 (54.93%) involved double-arm-zero-events studies. The majority (98.71%) of these systematic reviews incorporated single-arm-zero-events studies into the meta-analyses. On the other hand, the majority (76.23%) of them excluded double-arm-zero-events studies from the meta-analyses, of which the majority (87.06%) did not discuss the potential impact of excluding such studies. Systematic reviews published at present (2015-2020) tended to incorporate zero-events studies in meta-analyses than those published in the past (2008-2011), but the difference was not significant (proportion difference=-0.09, 95% CI -0.21 to 0.03, p = 0.12). CONCLUSION Systematic review authors routinely treated studies with zero-events in both arms as "non-informative" carriers and excluded them from their reviews. Whether studies with no events are "informative" or not largely depends on the methods and assumptions applied, thus sensitivity analyses using different methods should be considered in future meta-analyses.
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Affiliation(s)
- Chang Xu
- Department of Population Medicine, College of Medicine, Qatar University, Al Jamiaa Street, P. O. Box, 2713, Doha, Qatar.
| | - Xiaoqin Zhou
- Department of Clinical Research Management, West China Hospital, Sichuan University, Chengdu, China
| | - Liliane Zorzela
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ke Ju
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Luis Furuya-Kanamori
- UQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Lifeng Lin
- Department of Statistics, Florida State University, Tallahassee, FL, USA
| | - Cuncun Lu
- Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Omran A H Musa
- Department of Population Medicine, College of Medicine, Qatar University, Al Jamiaa Street, P. O. Box, 2713, Doha, Qatar
| | - Sunita Vohra
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Department of Psychiatry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
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12
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Kahale LA, Hakoum MB, Tsolakian IG, Matar CF, Terrenato I, Sperati F, Barba M, Yosuico VE, Schünemann H, Akl EA. Anticoagulation for the long-term treatment of venous thromboembolism in people with cancer. Cochrane Database Syst Rev 2018; 6:CD006650. [PMID: 29920657 PMCID: PMC6389342 DOI: 10.1002/14651858.cd006650.pub5] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Cancer increases the risk of thromboembolic events, especially in people receiving anticoagulation treatments. OBJECTIVES To compare the efficacy and safety of low molecular weight heparins (LMWHs), direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) for the long-term treatment of venous thromboembolism (VTE) in people with cancer. SEARCH METHODS We conducted a literature search including a major electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1), MEDLINE (Ovid), and Embase (Ovid); handsearching conference proceedings; checking references of included studies; use of the 'related citation' feature in PubMed and a search for ongoing studies in trial registries. As part of the living systematic review approach, we run searches continually, incorporating new evidence after it is identified. Last search date 14 May 2018. SELECTION CRITERIA Randomized controlled trials (RCTs) assessing the benefits and harms of long-term treatment with LMWHs, DOACs or VKAs in people with cancer and symptomatic VTE. DATA COLLECTION AND ANALYSIS We extracted data in duplicate on study characteristics and risk of bias. Outcomes included: all-cause mortality, recurrent VTE, major bleeding, minor bleeding, thrombocytopenia, and health-related quality of life (QoL). We assessed the certainty of the evidence at the outcome level following the GRADE approach (GRADE handbook). MAIN RESULTS Of 15,785 citations, including 7602 unique citations, 16 RCTs fulfilled the eligibility criteria. These trials enrolled 5167 people with cancer and VTE.Low molecular weight heparins versus vitamin K antagonistsEight studies enrolling 2327 participants compared LMWHs with VKAs. Meta-analysis of five studies probably did not rule out a beneficial or harmful effect of LMWHs compared to VKAs on mortality up to 12 months of follow-up (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.88 to 1.13; risk difference (RD) 0 fewer per 1000, 95% CI 45 fewer to 48 more; moderate-certainty evidence). Meta-analysis of four studies did not rule out a beneficial or harmful effect of LMWHs compared to VKAs on major bleeding (RR 1.09, 95% CI 0.55 to 2.12; RD 4 more per 1000, 95% CI 19 fewer to 48 more, moderate-certainty evidence) or minor bleeding (RR 0.78, 95% CI 0.47 to 1.27; RD 38 fewer per 1000, 95% CI 92 fewer to 47 more; low-certainty evidence), or thrombocytopenia (RR 0.94, 95% CI 0.52 to 1.69). Meta-analysis of five studies showed that LMWHs probably reduced the recurrence of VTE compared to VKAs (RR 0.58, 95% CI 0.43 to 0.77; RD 53 fewer per 1000, 95% CI 29 fewer to 72 fewer, moderate-certainty evidence).Direct oral anticoagulants versus vitamin K antagonistsFive studies enrolling 982 participants compared DOACs with VKAs. Meta-analysis of four studies may not rule out a beneficial or harmful effect of DOACs compared to VKAs on mortality (RR 0.93, 95% CI 0.71 to 1.21; RD 12 fewer per 1000, 95% CI 51 fewer to 37 more; low-certainty evidence), recurrent VTE (RR 0.66, 95% CI 0.33 to 1.31; RD 14 fewer per 1000, 95% CI 27 fewer to 12 more; low-certainty evidence), major bleeding (RR 0.77, 95% CI 0.38 to 1.57, RD 8 fewer per 1000, 95% CI 22 fewer to 20 more; low-certainty evidence), or minor bleeding (RR 0.84, 95% CI 0.58 to 1.22; RD 21 fewer per 1000, 95% CI 54 fewer to 28 more; low-certainty evidence). One study reporting on DOAC versus VKA was published as abstract so is not included in the main analysis.Direct oral anticoagulants versus low molecular weight heparinsTwo studies enrolling 1455 participants compared DOAC with LMWH. The study by Raskob did not rule out a beneficial or harmful effect of DOACs compared to LMWH on mortality up to 12 months of follow-up (RR 1.07, 95% CI 0.92 to 1.25; RD 27 more per 1000, 95% CI 30 fewer to 95 more; low-certainty evidence). The data also showed that DOACs may have shown a likely reduction in VTE recurrence up to 12 months of follow-up compared to LMWH (RR 0.69, 95% CI 0.47 to 1.01; RD 36 fewer per 1000, 95% CI 62 fewer to 1 more; low-certainty evidence). DOAC may have increased major bleeding at 12 months of follow-up compared to LMWH (RR 1.71, 95% CI 1.01 to 2.88; RD 29 more per 1000, 95% CI 0 fewer to 78 more; low-certainty evidence) and likely increased minor bleeding up to 12 months of follow-up compared to LMWH (RR 1.31, 95% CI 0.95 to 1.80; RD 35 more per 1000, 95% CI 6 fewer to 92 more; low-certainty evidence). The second study on DOAC versus LMWH was published as an abstract and is not included in the main analysis.Idraparinux versus vitamin K antagonistsOne RCT with 284 participants compared once-weekly subcutaneous injection of idraparinux versus standard treatment (parenteral anticoagulation followed by warfarin or acenocoumarol) for three or six months. The data probably did not rule out a beneficial or harmful effect of idraparinux compared to VKAs on mortality at six months (RR 1.11, 95% CI 0.78 to 1.59; RD 31 more per 1000, 95% CI 62 fewer to 167 more; moderate-certainty evidence), VTE recurrence at six months (RR 0.46, 95% CI 0.16 to 1.32; RD 42 fewer per 1000, 95% CI 65 fewer to 25 more; low-certainty evidence) or major bleeding (RR 1.11, 95% CI 0.35 to 3.56; RD 4 more per 1000, 95% CI 25 fewer to 98 more; low-certainty evidence). AUTHORS' CONCLUSIONS For the long-term treatment of VTE in people with cancer, evidence shows that LMWHs compared to VKAs probably produces an important reduction in VTE and DOACs compared to LMWH, may likely reduce VTE but may increase risk of major bleeding. Decisions for a person with cancer and VTE to start long-term LMWHs versus oral anticoagulation should balance benefits and harms and integrate the person's values and preferences for the important outcomes and alternative management strategies.Editorial note: this is a living systematic review (LSR). LSRs offer new approaches to review updating in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.
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Affiliation(s)
- Lara A Kahale
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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