Papers by Zbys Fedorowicz
JEBM
Aims: Breast cancer within the region continues to present challenges to the healthcare services.... more Aims: Breast cancer within the region continues to present challenges to the healthcare services.
Strategies to shed light on clinical gaps could better support country-specific circumstances. The
aims of the mapping study were to identify the gaps in the evidence base, for the management
of breast cancer with relevance to Bahrain and the Gulf Region. In parallel, focusing on areas and
directions of research, which are compatible with international and local clinical interests. It was
envisaged that the mapping project would expose not only opportunities to improve support to the
community but also illustrate the possible engagement of a government entity and a Nongovernment Organization in a private-public partnership.
Method: An extensive literature review of local and international publications from the period
between 1979 and 2015 was undertaken. Searches were conducted using free-text terms, singularly or combined, with no limiters, to provide unrestricted retrieval of available English studies.
Results: A total of 326 citations were identified, which after deduplication provided 277 unique
citations of which included 236 studies within 13 different categories, relevant to breast cancer
within the Gulf Cooperation Council (GCC).
Conclusion:Contextualizing gaps in literature and, therefore, providing evidence-based decisions,
not only support the enduser, but better support the country-specific challenges and burdens
to healthcare. Three broad but key areas were identified after mapping of the literature, covering:screening and mammography, knowledge translation and dissemination, and lymphoedema
postsurgical resection. Similar mapping projects could be undertaken by other national NGO’s to
better support the government and solidify the framework for a public-private partnership.
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JAMA Network Open, 2019
IMPORTANCE Hypertension is very common, but guideline recommendations for hypertension
have been ... more IMPORTANCE Hypertension is very common, but guideline recommendations for hypertension
have been controversial, are of increasing interest, and have profound implications.
OBJECTIVE To systematically assess the consistency of recommendations regarding hypertension
management across clinical practice guidelines (CPGs).
DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study of hypertension management
recommendations included CPGs that had been published as of April 2018. Two point-of-care
resources that provided graded recommendations were included for secondary analyses. Discrete
and unambiguous specifications of the population, intervention, and comparison states were used to
define a series of reference recommendations. Three raters reached consensus on coding the
direction and strength of each recommendation made by each CPG. Three independent raters
reached consensus on the importance of each reference recommendation.
MAIN OUTCOMES AND MEASURES The main outcomes were rates of consistency for direction and
strength among CPGs. Sensitivity analyses testing the robustness were conducted by excluding
recommendation statements that were described as insufficient evidence, excluding single
recommendation sources, and stratifying by importance of recommendations.
RESULTS The analysis included 8 CPGs with a total of 71 reference recommendations, 68 of which
had clear recommendations from 2 or more CPGs. Across CPGs, 22 recommendations (32%) were
consistent in direction and strength, 18 recommendations (27%) were consistent in direction but
inconsistent in strength, and 28 recommendations (41%) were inconsistent in direction. The rate of
consistency was lower in secondary analyses. When insufficient evidence ratings were excluded,
there was still substantial inconsistency, and a leave-one-out sensitivity analysis suggested the
inconsistency could not be attributed to any single recommendation source. Inconsistency in
direction was more common for recommendations deemed to be of lower importance (11 of 20
recommendations [55%]), but 17 of 48 high-importance recommendations (35%) had inconsistency
in direction.
CONCLUSIONS AND RELEVANCE Hypertension is a common chronic condition with widespread
expectations surrounding guideline-based care, yet CPGs have a high rate of inconsistency. Further
investigations should determine the reasons for inconsistency, the implications for recommendation
development, and the role of synthesis across recommendations for optimal guidance of clinical care.
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Cochrane Database of Systematic Reviews, Oct 15, 2014
Thalassemia is an inherited blood disorder, caused by mutations in regulatory genes and transmitt... more Thalassemia is an inherited blood disorder, caused by mutations in regulatory genes and transmitted as an autosomal recessive disorder, which results in a reduced rate of synthesis of one of the globin chains that make up haemoglobin. In ß-thalassaemia major there is an underproduction of ß-globin chains combined with excess of free α-globin chains. The excess free α-globin chains damage the red blood cell membranes, leading to their destruction and a phenomenon termed ineffective erythropoiesis. The conventional approach to treatment is based on the correction of haemoglobin status through regular blood transfusions and iron chelation therapy for iron overload. Although conventional treatment has the capacity to improve the quality of life of people with ß-thalassaemia major, allogeneic hematopoietic stem cell transplantation is the only currently available procedure which has the potential to definitively cure the disease. To evaluate the effectiveness and safety of different types of allogeneic hematopoietic stem cell transplantation, in people with severe transfusion-dependant ß-thalassaemia major, ß-thalassaemia intermedia or ß0/+- thalassaemia variants requiring chronic blood transfusion. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 11 November 2013. Randomised controlled trials and quasi-randomised controlled trials comparing allogeneic hematopoietic stem cell transplantation with each other or with standard therapy (regular transfusion and chelation regimen). Two review authors independently screened studies and had planned to extract data and assess risk of bias using standard Cochrane Collaboration methodologies but no studies were identified for inclusion. No relevant studies were retrieved after a comprehensive search of the literature. We were unable to identify any randomised controlled trials or quasi-randomised controlled trials on the effectiveness and safety of different types of allogeneic stem cell transplantation in people with severe transfusion-dependant ß-thalassaemia major or ß0/+- thalassaemia variants requiring chronic blood transfusion. The absence of high-level evidence for the effectiveness of these interventions emphasises the need for well-designed, adequately-powered, randomised controlled clinical trials.
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The Cochrane library, Jan 24, 2007
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The Cochrane library, May 30, 2019
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Cochrane Database of Systematic Reviews, Jun 12, 2013
Sickle cell disease is one of the most common and severe genetic disorders in the world. It can b... more Sickle cell disease is one of the most common and severe genetic disorders in the world. It can be broadly divided into two distinct clinical phenotypes characterized by either haemolysis or vaso-occlusion. Pain is the most prominent symptom of vaso-occlusion, and hypercoagulability is a well-established pathogenic phenomenon in people with sickle cell disease. Low-molecular-weight heparins might control this hypercoagulable state through their anticoagulant effect. To assess the effects of low-molecular-weight heparins for managing vaso-occlusive crises in people with sickle cell disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches. We also searched abstract books of conference proceedings and several online trials registries for ongoing trials.Date of the last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 6 December 2012. Randomised controlled clinical trials and controlled clinical trials that assessed the effects of low-molecular-weight heparins in the management of vaso-occlusive crises in people with sickle cell disease. Study selection, data extraction, assessment of risk of bias and analyses were carried out independently by the two review authors. One study (with an overall unclear to high risk of bias) comprising 253 participants was included. This study, with limited data, reported that pain severity at day two and day three was lower in the tinzaparin group than in the placebo group (P < 0.01, analysis of variance (ANOVA)) and additionally at day 4 (P < 0.05 (ANOVA)). Thus tinzaparin resulted in more rapid resolution of pain, as measured with a numerical pain scale. The mean difference in duration of painful crises was statistically significant at -1.78 days in favour of the tinzaparin group (95% confidence interval -1.94 to -1.62). Participants treated with tinzaparin had statistically significantly fewer hospitalisation days than participants in the group treated with placebo, with a mean difference of -4.98 days (95% confidence interval -5.48 to -4.48). Two minor bleeding events were reported as adverse events in the tinzaparin group, and none were reported in the placebo group. Based on the results of one study, evidence is incomplete to support or refute the effectiveness of low-molecular-weight heparins in people with sickle cell disease. Vaso-occlusive crises are extremely debilitating for sufferers of sickle cell disease; therefore well-designed placebo-controlled studies with other types of low-molecular-weight heparins, and in participants with different genotypes of sickle cell disease, still need to be carried out to confirm or dismiss the results of this single study.
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Cochrane Database of Systematic Reviews, Oct 5, 2011
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Cochrane Database of Systematic Reviews, Oct 8, 2008
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Cochrane Database of Systematic Reviews, Apr 15, 2009
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Cochrane Database of Systematic Reviews, Dec 19, 2013
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Contact Dermatitis, 2024
The Global Guidelines in Dermatology Mapping Project (GUIDEMAP) assesses the methodological quali... more The Global Guidelines in Dermatology Mapping Project (GUIDEMAP) assesses the methodological quality of clinical practice guidelines (CPGs) for high-burden skin diseases. This review focuses on contact dermatitis. We searched MEDLINE, Embase, PubMed, Web of Science, Cochrane Library, Emcare, Epistemonikos, PsycINFO and Academic Search Premier for CPGs published between 1 November 2018 and 1 November 2023. Prespecified guideline resources were hand searched. Two authors independently undertook screening, data extraction and quality assessments. Instruments used were the Appraisal of Guidelines for Research and Evaluation (AGREE) II Reporting Checklist, the U.S. Institute of Medicine's (IOM) criteria of trustworthiness, The Agency for Healthcare Research and Quality's National Guideline Clearinghouse Extent Adherence to Trustworthy Standards (NEATS) Instrument and Lenzer's Red Flags. Twenty five CPGs were included, exhibiting heterogeneity in both the topics they addressed and their methodological quality. Whereas the CPGs on management of hand eczema from Denmark, Europe and the Netherlands scored best, most CPGs fell short of being clear, unbiased, trustworthy and evidence-based. Disclosure of conflicts of interest scored well, and areas needing improvement include ‘strength and wording of recommendations’, ‘applicability’, ‘updating’ and ‘external review’. Adhering to AGREE II and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) enhances methodological quality.
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Cochrane Database of Systematic Reviews, Jun 13, 2012
Multiple sclerosis (MS) is a leading cause of neurological disability in young adults. The most w... more Multiple sclerosis (MS) is a leading cause of neurological disability in young adults. The most widely accepted hypothesis regarding its pathogenesis is that it is an immune-mediated disease. It has been hypothesised more recently that chronic venous congestion may be an important factor in the pathogenesis of MS. This concept has been named 'chronic cerebrospinal venous insufficiency' (CCSVI) and is characterised by stenoses of either the internal jugular or azygos veins, or both. It is suggested that these stenoses restrict the normal blood flow from the brain, causing the deposition of iron in the brain and the eventual triggering of an auto-immune response. The proposed treatment for CCSVI is percutaneous transluminal angioplasty, also known as the 'liberation procedure', which is claimed to improve the blood flow in the brain thereby alleviating some of the symptoms of MS. To assess the effects of percutaneous transluminal angioplasty for the treatment of CCSVI in people with MS. We searched the following databases up to June 2012: The Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Specialised Register, CENTRAL in The Cochrane Library 2012, Issue 5, MEDLINE (from 1946), EMBASE (from 1974), and reference lists of articles. We also searched several online trials registries for ongoing trials. Randomised controlled trials assessing the effects of percutaneous transluminal angioplasty in adults with multiple sclerosis, that have been diagnosed to have CCSVI. Our searches retrieved 159 references, six of which were to ongoing trials. Based on assessment of the title or abstract, or both, we excluded all of the studies, with the exception of one which was evaluated following examination of the full text report. However, this study also did not meet our inclusion criteria and was subsequently excluded. No randomised controlled trials met our inclusion criteria. There is currently no high level evidence to support or refute the efficacy or safety of percutaneous transluminal angioplasty for treatment of CCSVI in people with MS. Clinical practice should be guided by evidence supported by well-designed randomised controlled trials: closure of some of the gaps in the evidence may be feasible at the time of completion of the six ongoing clinical trials.
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The Cochrane library, May 26, 2016
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Cochrane Database of Systematic Reviews, Apr 15, 2009
Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria fr... more Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria from the biofilm (dental plaque) leads to localised demineralisation of tooth surfaces, which may ultimately result in cavity formation. Resin composites are widely used in dentistry to restore teeth. These restorations can fail for a number of reasons, such as secondary caries, excessive wear, marginal degradation, tooth sensitivity, pulpal death, and restorative material fracture. Caries adjacent to restorations is one of the main causes for restoration replacement. The presence of antibacterials in both the filling material and the bonding systems would theoretically be able to affect the initiation and progression of caries adjacent to restorations.
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Hemoglobin, May 14, 2014
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Cochrane Database of Systematic Reviews, Jan 20, 2010
This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 2010 a... more This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 2010 and previously updated in 2011.Tonsillectomy is the surgical removal of lymphoid tissue, the palatine tonsil, which is located at the back of the throat. It is still commonly performed for patients who have recurrent bouts of acute tonsillitis. Although tonsillectomy is considered a fairly minor procedure, pain and bleeding are two of the most common complications; either may delay recovery and can on occasion lead to hospital readmission. Postoperative tonsillectomy medication should provide an adequate reduction in morbidity while minimising side effects, therefore topical agents would seem to be an ideal, safe option. A number of mouthwashes and topical sprays are available which offer pain relief or can help to reduce bleeding in the immediate postoperative period. To assess the effects of oral rinses, mouthwashes and sprays in improving recovery following tonsillectomy. We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 4 July 2013. We included randomised controlled trials in which oral rinses, mouthwashes and sprays, used pre- and postoperatively, have been compared with placebo in adults or children undergoing tonsillectomy, with or without adenoidectomy. Two review authors selected trials for inclusion, assessed the risk of bias and extracted data independently. We included seven trials (593 participants; 397 children and 196 adults). The period of follow-up ranged from 24 hours to two weeks. Few of the trials provided reliable data for the pre-specified primary outcomes and none for the secondary outcomes. The risk of bias was high in most of the included trials. Lidocaine spray appeared to be more effective than saline spray at reducing the severity of pain until the third postoperative day. A small number of participants experienced a burning or stinging sensation with benzydamine spray but not sufficient to discontinue usage. Poor reporting quality and inadequate data did not permit comprehensive and reliable conclusions to be made. Future trials should be well-constructed and pay more attention to the methods used to assess outcomes, the timing of the assessments, and the quality of reporting and subsequent analysis of the data.
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The Cochrane library, Dec 18, 2015
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Cochrane Database of Systematic Reviews, Jan 24, 2005
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Cochrane Database of Systematic Reviews, Apr 18, 2007
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Papers by Zbys Fedorowicz
Strategies to shed light on clinical gaps could better support country-specific circumstances. The
aims of the mapping study were to identify the gaps in the evidence base, for the management
of breast cancer with relevance to Bahrain and the Gulf Region. In parallel, focusing on areas and
directions of research, which are compatible with international and local clinical interests. It was
envisaged that the mapping project would expose not only opportunities to improve support to the
community but also illustrate the possible engagement of a government entity and a Nongovernment Organization in a private-public partnership.
Method: An extensive literature review of local and international publications from the period
between 1979 and 2015 was undertaken. Searches were conducted using free-text terms, singularly or combined, with no limiters, to provide unrestricted retrieval of available English studies.
Results: A total of 326 citations were identified, which after deduplication provided 277 unique
citations of which included 236 studies within 13 different categories, relevant to breast cancer
within the Gulf Cooperation Council (GCC).
Conclusion:Contextualizing gaps in literature and, therefore, providing evidence-based decisions,
not only support the enduser, but better support the country-specific challenges and burdens
to healthcare. Three broad but key areas were identified after mapping of the literature, covering:screening and mammography, knowledge translation and dissemination, and lymphoedema
postsurgical resection. Similar mapping projects could be undertaken by other national NGO’s to
better support the government and solidify the framework for a public-private partnership.
have been controversial, are of increasing interest, and have profound implications.
OBJECTIVE To systematically assess the consistency of recommendations regarding hypertension
management across clinical practice guidelines (CPGs).
DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study of hypertension management
recommendations included CPGs that had been published as of April 2018. Two point-of-care
resources that provided graded recommendations were included for secondary analyses. Discrete
and unambiguous specifications of the population, intervention, and comparison states were used to
define a series of reference recommendations. Three raters reached consensus on coding the
direction and strength of each recommendation made by each CPG. Three independent raters
reached consensus on the importance of each reference recommendation.
MAIN OUTCOMES AND MEASURES The main outcomes were rates of consistency for direction and
strength among CPGs. Sensitivity analyses testing the robustness were conducted by excluding
recommendation statements that were described as insufficient evidence, excluding single
recommendation sources, and stratifying by importance of recommendations.
RESULTS The analysis included 8 CPGs with a total of 71 reference recommendations, 68 of which
had clear recommendations from 2 or more CPGs. Across CPGs, 22 recommendations (32%) were
consistent in direction and strength, 18 recommendations (27%) were consistent in direction but
inconsistent in strength, and 28 recommendations (41%) were inconsistent in direction. The rate of
consistency was lower in secondary analyses. When insufficient evidence ratings were excluded,
there was still substantial inconsistency, and a leave-one-out sensitivity analysis suggested the
inconsistency could not be attributed to any single recommendation source. Inconsistency in
direction was more common for recommendations deemed to be of lower importance (11 of 20
recommendations [55%]), but 17 of 48 high-importance recommendations (35%) had inconsistency
in direction.
CONCLUSIONS AND RELEVANCE Hypertension is a common chronic condition with widespread
expectations surrounding guideline-based care, yet CPGs have a high rate of inconsistency. Further
investigations should determine the reasons for inconsistency, the implications for recommendation
development, and the role of synthesis across recommendations for optimal guidance of clinical care.
Strategies to shed light on clinical gaps could better support country-specific circumstances. The
aims of the mapping study were to identify the gaps in the evidence base, for the management
of breast cancer with relevance to Bahrain and the Gulf Region. In parallel, focusing on areas and
directions of research, which are compatible with international and local clinical interests. It was
envisaged that the mapping project would expose not only opportunities to improve support to the
community but also illustrate the possible engagement of a government entity and a Nongovernment Organization in a private-public partnership.
Method: An extensive literature review of local and international publications from the period
between 1979 and 2015 was undertaken. Searches were conducted using free-text terms, singularly or combined, with no limiters, to provide unrestricted retrieval of available English studies.
Results: A total of 326 citations were identified, which after deduplication provided 277 unique
citations of which included 236 studies within 13 different categories, relevant to breast cancer
within the Gulf Cooperation Council (GCC).
Conclusion:Contextualizing gaps in literature and, therefore, providing evidence-based decisions,
not only support the enduser, but better support the country-specific challenges and burdens
to healthcare. Three broad but key areas were identified after mapping of the literature, covering:screening and mammography, knowledge translation and dissemination, and lymphoedema
postsurgical resection. Similar mapping projects could be undertaken by other national NGO’s to
better support the government and solidify the framework for a public-private partnership.
have been controversial, are of increasing interest, and have profound implications.
OBJECTIVE To systematically assess the consistency of recommendations regarding hypertension
management across clinical practice guidelines (CPGs).
DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study of hypertension management
recommendations included CPGs that had been published as of April 2018. Two point-of-care
resources that provided graded recommendations were included for secondary analyses. Discrete
and unambiguous specifications of the population, intervention, and comparison states were used to
define a series of reference recommendations. Three raters reached consensus on coding the
direction and strength of each recommendation made by each CPG. Three independent raters
reached consensus on the importance of each reference recommendation.
MAIN OUTCOMES AND MEASURES The main outcomes were rates of consistency for direction and
strength among CPGs. Sensitivity analyses testing the robustness were conducted by excluding
recommendation statements that were described as insufficient evidence, excluding single
recommendation sources, and stratifying by importance of recommendations.
RESULTS The analysis included 8 CPGs with a total of 71 reference recommendations, 68 of which
had clear recommendations from 2 or more CPGs. Across CPGs, 22 recommendations (32%) were
consistent in direction and strength, 18 recommendations (27%) were consistent in direction but
inconsistent in strength, and 28 recommendations (41%) were inconsistent in direction. The rate of
consistency was lower in secondary analyses. When insufficient evidence ratings were excluded,
there was still substantial inconsistency, and a leave-one-out sensitivity analysis suggested the
inconsistency could not be attributed to any single recommendation source. Inconsistency in
direction was more common for recommendations deemed to be of lower importance (11 of 20
recommendations [55%]), but 17 of 48 high-importance recommendations (35%) had inconsistency
in direction.
CONCLUSIONS AND RELEVANCE Hypertension is a common chronic condition with widespread
expectations surrounding guideline-based care, yet CPGs have a high rate of inconsistency. Further
investigations should determine the reasons for inconsistency, the implications for recommendation
development, and the role of synthesis across recommendations for optimal guidance of clinical care.
Need: Breast Cancer leading type of cancer for women in the Eastern Mediterranean Region (EMR) commonest in the six Gulf Cooperation Council (GCC) countries.1 Previous guideline (2010). “Guideline for Management of Periodic Screening in Primary Care Settings and Outpatient Clinics in the Kingdom of Bahrain” (MoH Bahrain).
Scope & Purpose of updated guideline: screening, diagnosis and staging, treatment to include surgery, chemotherapy / hormone therapy and radiotherapy in addition to post treatment surveillance and management of recurrence.