ABSTRACT BACKGROUND: Although the concept of an “ongoing study” seems self-explanatory, it is difficult to determine whether a trial is underway. OBJECTIVE: To analyze the definitions of “ongoing clinical trial” across different clinical trial registries, methodological guidelines, and other sources. DESIGN AND SETTING: This meta-research study was conducted at the Universidade Federal de São Paulo (UNIFESP), Brazil. METHODS: We performed a cross-sectional analysis of relevant clinical trial registry databases, methodological guidelines for conducting systematic reviews, and other sources that would define or regulate clinical trials. RESULTS: We identified various heterogeneous definitions used by eligible sources at both the start and end of a clinical trial. The starting criteria used were as follows: when the team is planning the protocol, when permission is given to conduct the study, or when the first participant is enrolled. Some sources used the time at which the last outcome data was collected as a criterion to determine the end of the trial. The International Committee of Medical Journal Editors stated that a study is still “ongoing” during the analysis process. Several sources use a vague definition or present no clear criteria for defining the start or end of a study. CONCLUSION: The concept of “ongoing clinical trials” lacks a transparent and homogeneous definition across relevant sources. A consensus on this concept is important to facilitate the evaluation of available evidence and conduct research synthesis. Further efforts are necessary to determine the best definition for the start and end of a clinical trial. BACKGROUND ongoing selfexplanatory, selfexplanatory self explanatory, explanatory self-explanatory underway OBJECTIVE registries SETTING metaresearch meta UNIFESP, UNIFESP , (UNIFESP) Brazil METHODS crosssectional cross sectional databases reviews trials RESULTS follows protocol enrolled process CONCLUSION synthesis (UNIFESP

SUMMARY OBJECTIVE: The aim of this study was to identify the frequency of Cochrane systematic reviews and Cochrane systematic reviews protocols using (or planning to use) the risk of bias 2.0 tool to assess the risk of bias of the included randomized clinical trials. STUDY DESIGN: This is a meta-research study. METHODS: We included Cochrane systematic reviews or Cochrane systematic reviews protocols that planned to include randomized clinical trials. We assessed the Cochrane Database of Systematic Reviews and screened for issues published after the launch of risk of bias 2.0 tool (2019–2022). Two independent investigators performed the study selection and data extraction. RESULTS: We analyzed 440 Cochrane systematic reviews and 536 Cochrane systematic reviews protocols. Overall, 4.8% of the Cochrane systematic reviews and 28.5% of the Cochrane systematic reviews protocols used or planned to use risk of bias 2.0 tool. Although low, adherence is increasing over time. In 2019, 0% of Cochrane systematic reviews used risk of bias 2.0 tool, compared to 24.1% in 2022. In Cochrane systematic reviews protocols, adherence increased from 6.9% in 2019 to 41.5% in 2022. A total of 274 (62.1%) Cochrane systematic reviews had their protocols published before 2018; only one used risk of bias 2.0 tool and reported the change of versions in the “Differences between protocol and revision” section. CONCLUSION: The Cochrane's risk of bias 2.0 tool has low adherence among Cochrane protocols and systematic reviews. Further efforts are necessary to facilitate the implementation of this new tool. OBJECTIVE 20 2 0 2. trials DESIGN metaresearch meta research METHODS 2019–2022. 20192022 2019–2022 . 2022 (2019–2022) extraction RESULTS 44 53 Overall 48 4 8 4.8 285 28 5 28.5 time 241 24 1 24.1 69 6 9 6.9 201 415 41 41.5 27 62.1% 621 62 (62.1% 2018 Differences revision section CONCLUSION Cochranes s 2019202 2019–202 202 (2019–2022 4. 28. 24. 6. 41. 62.1 (62.1 201920 2019–20 (2019–202 62. (62. 20192 2019–2 (2019–20 (62 2019– (2019–2 (6 (2019– ( (2019 (201 (20 (2

ABSTRACT BACKGROUND: Imaging tests are important for diagnosis during the management of pulmonary nodules; however, biopsy is required to confirm the malignancy. OBJECTIVES: To compare the effects of different techniques used for the biopsy of a pulmonary nodule. DESIGN AND SETTING: Systematic review and meta-analysis were conducted using Cochrane methodology in São Paulo, São Paulo, Brazil. METHODS: We conducted a systematic review of randomized controlled trials (RCTs) on minimally invasive techniques, including tomography-guided percutaneous biopsy (PERCUT), transbronchial biopsies with fluoroscopy (FLUOR), endobronchial ultrasound (EBUSR), and electromagnetic navigation (NAVIG). The primary outcomes were diagnostic yield, major adverse events, and need for another approach. RESULTS: Seven RCTs were included (913 participants; 39.2% female, mean age: 59.28 years). Little to no increase was observed in PERCUT over FLUOR (P = 0.84), PERCUT over EBUSR (P = 0.32), and EBUSR over NAVIG (P = 0.17), whereas a slight increase was observed in NAVIG over FLUOR (P = 0.17); however, the evidence was uncertain. EBUSR may increase the diagnostic yield over FLUOR (P = 0.34). PERCUT showed little to no increase in all bronchoscopic techniques, with uncertain evidence (P = 0.02). CONCLUSION: No biopsy method is definitively superior to others. The preferred approach must consider availability, accessibility, and cost, as safety and diagnostic yield do not differ. Further RCTs planned, conducted, and reported with methodological rigor and transparency are needed, and additional studies should assess cost and the correlation between nodule size and location, as well as their association with biopsy results. SYSTEMATIC REVIEW REGISTRATION: PROSPERO database, CRD42018092367 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=92367. BACKGROUND nodules however malignancy OBJECTIVES SETTING metaanalysis meta analysis Paulo Brazil METHODS (RCTs tomographyguided tomography guided PERCUT, , (PERCUT) FLUOR, (FLUOR) EBUSR, (EBUSR) NAVIG. . (NAVIG) events RESULTS 913 (91 participants 392 39 2 39.2 female age 5928 59 28 59.2 years. years years) P 0.84, 084 0.84 0 84 0.84) 0.32, 032 0.32 32 0.32) 0.17, 017 0.17 17 0.17) 0.34. 034 0.34 34 0.34) 0.02. 002 0.02 02 0.02) CONCLUSION others availability accessibility differ planned needed location results REGISTRATION database CRD CRD4201809236 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=92367. httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID92367 httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID https //www.crd.york.ac.uk/PROSPERO/display_record.php RecordID=92367. www crd york ac uk display record php RecordID 92367 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=92367 (PERCUT (FLUOR (EBUSR (NAVIG 91 (9 3 39. 592 5 59. 08 0.8 8 03 0.3 01 0.1 1 00 0.0 CRD420180923 phpRecordID https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=92367 httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID9236 wwwcrdyorkacukPROSPEROdisplayrecordphp RecordID92367 RecordID=92367 9236 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=9236 9 ( 0. CRD42018092 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=9236 httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID923 RecordID9236 RecordID=9236 923 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=923 CRD4201809 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=923 httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID92 RecordID923 RecordID=923 92 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=92 CRD420180 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=92 httpswwwcrdyorkacukPROSPEROdisplayrecordphpRecordID9 RecordID92 RecordID=92 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=9 CRD42018 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID=9 RecordID9 RecordID=9 -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID= CRD4201 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID= RecordID= -https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID CRD420 https//www.crd.york.ac.uk/PROSPERO/display_record.phpRecordID CRD42 CRD4

Health professionals are encouraged to attend a residency period of two to seven years after graduating. The typical demands of this in-service training modality have been associated with reduced sleep quality, decreased exercise frequency, and detachment from family and social relationships, leading to an increased diagnosis of anxiety, depression, and burnout syndrome. Therefore, conducting a scoping review to identify strategies aimed at promoting mental health and wellbeing among residents from different health areas is essential to support any forthcoming preventive action.

ABSTRACT BACKGROUND: Numerous systematic reviews on coronavirus disease-19 (COVID-19) treatment have been developed to provide syntheses of the large volume of primary studies. However, the methodological quality of most of these reviews is questionable and the results provided may therefore present bias. OBJECTIVE: To investigate how many systematic reviews on the therapeutic or preventive options for COVID-19 assessed the certainty of the evidence through the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. METHODS: We conducted a sensitive search in MEDLINE (via PubMed) and included all systematic reviews that assessed any intervention for COVID-19. The systematic reviews included were examined to identify any planned and/or actual assessment using the GRADE approach (or absence thereof) regarding the certainty of the evidence. RESULTS: We included 177 systematic reviews and found that only 37 (21%; 37/177) assessed and reported the certainty of the evidence using the GRADE approach. This number reduced to 27 (16.2%; 27/167) when Cochrane reviews (n = 10), in which an evaluation using GRADE is mandatory, were excluded. CONCLUSION: Most of the systematic reviews on interventions relating to COVID-19 omitted assessment of the certainty of the evidence. This is a critical methodological omission that must not be overlooked in further research, so as to improve the impact and usefulness of syntheses relating to COVID-19.

Resumo Objetivo Nós realizamos uma revisão sistemática para avaliar a efetividade e a segurança do Tribulus terrestris no tratamento da disfunção sexual feminina (DSF). Fontes de dados Nós realizados uma busca eletrônica irrestrita nas seguintes bases de dados: MEDLINE, CENTRAL, EMBASE, LILACS, CINAHL, PsycINFO, WHO-ICTR, Clinicaltrials.gov, e OpenGrey. Seleção dos estudos Nós incluímos todos os ensaios clínico randomizados (ECR) que comparou T. terrestris com controles ativos/inativos. Após o processo de seleção, conduzido por 2 revisores, 5 ECRs (n = 279 participantes) foram incluídos. Extração de dados O processo de extração de dados foi realizado por dois revisores, utilizando-se um formulário de extração de dados pré-estabelecido. Síntese de dados Devido à falta de dados disponíveis e à heterogeneidade clínica entre os estudos incluídos, nós não realizamos meta-análises. O risco de viés foi avaliado pela tabela de risco de viés da Cochrane e, a certeza do corpo da evidência foi avaliada pelo Grading of Recommendations, Assessment, Development and Evaluations (GRADE). Resultados Após 1 a três 3 meses de tratamento, mulheres na pré e pós-menopausa randomizadas ao T. terrestris tiveram um aumento significante nos escores de função sexual. O grupo com 3 meses de tratamento com T. terrestris exibiu um aumento significante dos níveis séricos de testosterona emmulheres pré-menopausa. Não houve relato de eventos adversos graves, e nenhum estudo avaliou qualidade de vida das participantes. A certeza da evidência foi considerada muito baixa, o que significa que existe pouca certeza na estimativa dos efeitos e que é provável que futuros estudos mudem estas estimativas. Conclusão Mais ECRs são importantes para apoiar ou refutar o uso do T. terrestris. A decisão de usar essa intervenção deve ser compartilhada com pacientes, e as incertezas sobre seus efeitos devem ser discutidas durante o processo de decisão clínica.

Abstract Objective We performed a systematic review to assess the effectiveness and safety of Tribulus terrestris to treat female sexual dysfunction (FSD). Data sources We performed unrestricted electronic searches in the MEDLINE, CENTRAL, EMBASE, LILACS, CINAHL, PsycINFO,WHO-ICTR, Clinicaltrials.gov and OpenGrey databases. Selection of studies We included any randomized controlled trials (RCTs) that compared T. terrestris versus inactive/active interventions. After the selection process, conducted by two reviewers, 5 RCTs (n = 279 participants) were included. Data collection Data extraction was performed by two reviewers with a preestablished data collection formulary. Data synthesis Due to lack of data and clinical heterogeneity, we could not perform meta-analyses. The risk of bias was assessed by the Cochrane Risk of Bias (RoB) tool, and the certainty of evidence was assessed with Grading of Recommendations, Assessment, Development and Evaluations (GRADE). Results After 1 to 3 months of treatment, premenopausal and postmenopausal women randomized to T. terrestris had a significant increase in sexual function scores. Three months of treatment with T. terrestris showed a significant increase in the serum testosterone levels of premenopausal women. There was no report of serious adverse events, and none of the studies assessed health-related quality of life. The certainty of the evidence was very low, whichmeans that we have very little confidence in the effect estimates, and future studies are likely to change these estimates. Conclusion MoreRCTs are needed to supportor refute the use of T. terrestris. The decision to use this intervention should be shared with the patients, and the uncertainties around its effects should be discussed in the clinical decision-making process. Number of Protocol registration in PROSPERO database: CRD42019121130

ABSTRACT BACKGROUND: Age-related macular degeneration (AMD) is the third largest cause of blindness worldwide, accounting for 8.7% of all cases. A considerable number of preventive or therapeutic interventions have been used for AMD. OBJECTIVE: This study presents a critical view of the interventions that have been assessed through Cochrane systematic reviews. DESIGN AND SETTING: Review of systematic reviews, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP). METHODS: Review of Cochrane systematic reviews about interventions for AMD. RESULTS: The 18 systematic reviews included assessed the effects of surgical techniques, laser/photo/radiotherapy, intravitreal injections, systemic drugs and phytotherapy/vitamins/supplements. CONCLUSION: The Cochrane systematic reviews found evidence that use of bevacizumab, ranibizumab, pegaptanib, laser photocoagulation, photodynamic therapy and multivitamin compounds may present some benefits for treating AMD. There was insufficient evidence for supporting the use of macular translocation, submacular surgery, steroid implantation, radiotherapy, intravitreal aflibercept, interferon alfa, statins or omega-3 fatty acids for treating AMD; or the use of multivitamin antioxidant vitamins or mineral supplementation for preventing AMD. Future randomized controlled trials are imperative to reduce the uncertainty in several clinical questions regarding AMD.

ABSTRACT BACKGROUND: Irritable bowel syndrome (IBS) is a clinical disorder associated with high socioeconomic burden. Despite its importance, management of IBS remains difficult and several interventions have been hypothesized as beneficial for this condition. This study identified and summarized all Cochrane systematic reviews (SRs) about the effects of interventions for managing IBS patients. DESIGN AND SETTING: Review of systematic reviews, carried out in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP). METHODS: Review of Cochrane SRs addressing interventions for IBS. RESULTS: We included six SRs assessing acupuncture, bulking agents, antispasmodics, antidepressants, herbal medicines, homeopathy, hypnotherapy and psychological therapy for IBS. The certainty of evidence ranged from unknown to moderate, mainly due to imprecision in the estimates and high risk of bias from the primary studies included. There was moderate certainty of evidence that acupuncture had no important benefit regarding improvement of symptoms and quality of life, compared with sham acupuncture. There was also very low certainty of evidence that homeopathic asafoetida, used alone or in association with nux, was better than placebo regarding self-reported overall improvement. CONCLUSION: There was moderate certainty of evidence that acupuncture had no important benefit regarding improvement of symptoms and quality of life. Further well-designed and well-conducted randomized clinical trials are needed in order to reduce the uncertainties regarding the most commonly used interventions for patients with IBS.

ABSTRACT CONTEXT AND OBJECTIVE: Insomnia is a frequent complaint that generates more than five million visits to doctors per year in the United States. This study summarizes all Cochrane systematic reviews (SRs) that evaluated interventions to treat insomnia. DESIGN AND SETTING: Review of SRs, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP). METHODS: A sensitive search was carried out in the Cochrane Database of Systematic Reviews to identify Cochrane SRs that assessed the effects of any type of intervention for people with insomnia. The results, main characteristics of the SRs and the certainty of the evidence obtained from them were synthesized and discussed. RESULTS: Seven SRs were included. They addressed the benefits and harm of acupuncture (n = 1), behavioral interventions (n = 1), music (n = 1), pharmacotherapy (n = 2), phototherapy (n = 1) and physical exercise (n = 1). The certainty of the evidence ranged from moderate to very low. CONCLUSION: Acupuncture, music, physical exercise, paroxetine, doxepin, trimipramine and trazodone seem to present some benefit for patients with insomnia. However, the uncertainty around these results means that no robust and definitive recommendations for clinical practice can be made until the benefits and harms from each intervention for patients with insomnia have been confirmed through further studies.

ABSTRACT BACKGROUND: The therapeutic effects of cannabinoid compounds have been the center of many investigations. This study provides a synthesis on all Cochrane systematic reviews (SRs) that assessed the use of cannabinoids as a therapeutic approach. DESIGN AND SETTING: Review of SRs, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP). METHODS: A broad search was conducted in the Cochrane Database of Systematic Reviews to retrieve any Cochrane SRs that assessed the efficacy and safety of cannabinoids as a therapeutic approach. The results and key characteristics of all reviews included were summarized and discussed. RESULTS: Eight SRs were included. They assessed the use of cannabinoids for the following types of conditions: neurological (two SRs), psychiatric (two SRs), rheumatological (one SR), infectious (one SR) and oncological (two SRs). There was moderate-quality evidence showing that the use of cannabinoids reduced nausea and vomiting among adults, compared with placebo. Additionally, there was moderate-quality evidence showing that there was no difference between cannabinoids and prochlorperazine regarding the number of participants who reported vomiting, in this same population. CONCLUSIONS: This review identified eight Cochrane systematic reviews that provided evidence of unknown to moderate quality regarding the use of cannabinoids as a therapeutic intervention. Further studies are still imperative for solid conclusions to be reached regarding practical recommendations.

ABSTRACT CONTEXT AND OBJECTIVE: Psoriasis is a common chronic inflammatory skin disease characterized by abnormal and increased growth of the cells that produce keratin and abnormal functioning of the immune system. We aimed to summarize the evidence available regarding interventions for patients with psoriasis. DESIGN AND SETTING: Review of systematic reviews, developed in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo. METHODS: A systematic search was conducted to identify Cochrane systematic reviews that fulfilled the eligibility criteria. Two authors screened titles and abstracts that had been retrieved through the search strategy. The results from all the Cochrane systematic reviews that were included were summarized and presented in a narrative synthesis. RESULTS: We included six Cochrane systematic reviews assessing interventions for treating psoriasis. The findings from high-quality evidence were that (a) etanercept reduced the psoriasis severity index, compared with placebo and (b) steroids plus vitamin D, compared with vitamin D alone, improved the skin clearance rate, as assessed by investigators, but was associated with a higher proportion of participants who dropped out due to adverse events. For all other comparisons, the quality of the evidence ranged from moderate to very low. CONCLUSION: This review included six Cochrane systematic reviews that provided evidence ranging in quality from unknown to high, regarding management of psoriasis. Further randomized controlled trials are imperative to reduce the uncertainties relating to several treatments that are already used in clinical practice.

ABSTRACT BACKGROUND: This study identified and summarized all Cochrane systematic reviews (SRs) on the effects of ten integrative practices that were recently added to the Brazilian public healthcare system (SUS). DESIGN AND SETTING: Review of systematic reviews, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (Unifesp). METHODS: Review of Cochrane SRs on the following interventions were identified, summarized and critically assessed: apitherapy, aromatherapy, bioenergetics, family constellation, flower therapy, chromotherapy, geotherapy, hypnotherapy, hand imposition or ozone therapy. RESULTS: We included a total of 16 SRs: 4 on apitherapy, 4 on aromatherapy, 6 on hypnotherapy and 2 on ozone therapy. No Cochrane SR was found regarding bioenergetics, family constellation, chromotherapy, clay therapy, flower therapy or hand imposition. The only high-quality evidence was in relation to the potential benefit of apitherapy, specifically regarding some benefits from honey dressings for partial healing of burn wounds, for reduction of coughing among children with acute coughs and for preventing allergic reactions to insect stings. CONCLUSION: Except for some specific uses of apitherapy (honey for burn wounds and for acute coughs and bee venom for allergic reactions to insect stings), the use of ten integrative practices that have recently been incorporated into SUS does not seem to be supported by evidence from Cochrane SRs.

ABSTRACT CONTEXT AND OBJECTIVE: Cardiac arrest is associated with high morbidity and mortality and imposes a significant burden on the healthcare system. Management of cardiac arrest patients is complex and involves approaches with multiple interventions. Here, we aimed to summarize the available evidence regarding the interventions used in cardiac arrest cases. DESIGN AND SETTING: Review of systematic reviews (SRs), conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo. METHODS: A systematic search was conducted to identify all Cochrane SRs that fulfilled the inclusion criteria. Titles and abstracts were screened by two authors. RESULTS: We included nine Cochrane SRs assessing compression techniques or devices (three SRs), defibrillation (two SRs) and other interventions (two SRs on hypothermia interventions, one on airway management and one on pharmacological intervention). The reviews included found qualities of evidence ranging from unknown to high, regarding the benefits of these interventions. CONCLUSION: This review included nine Cochrane systematic reviews that provided a diverse range of qualities of evidence (unknown to high) regarding interventions that are used in management of cardiac arrest. High-quality evidence was found by two systematic reviews as follows: (a) increased survival until hospital discharge with continuous compression, compared with interrupted chest compression, both administered by an untrained person and (b) no difference regarding the return of spontaneous circulation, comparing aminophylline and placebo, for bradyasystolic patients under cardiac arrest. Further studies are needed in order to reach solid conclusions.

ABSTRACT BACKGROUND: Urinary incontinence is a highly prevalent condition that impacts self-esteem and overall quality of life. Many non-surgical treatment options are available, ranging from pharmacological approaches to pelvic exercises. We aimed to summarize the available evidence regarding these non-surgical interventions. DESIGN AND SETTING: Review of systematic reviews, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP). METHODS: A sensitive search was conducted to identify all Cochrane systematic reviews that fulfilled the inclusion criteria. Titles and abstracts were screened by two authors. RESULTS: We included 20 Cochrane systematic reviews: 4 assessing methods of vesical training, 3 evaluating pharmacological interventions, 4 studying pelvic floor muscle training approaches and 9 aimed at other alternatives (such as urethral injections, weighted vaginal cone use, acupuncture, biostimulation and radiofrequency therapy). The reviews found that the evidence regarding the benefits of these diverse interventions ranged in quality from low to high. CONCLUSIONS: This review included 20 Cochrane systematic reviews that provided evidence (of diverse quality) for non-pharmacological interventions for patients with urinary incontinence. Moderate to high quality of evidence was found favoring the use of pelvic floor muscle training among women with urinary incontinence. To establish solid conclusions for all the other comparisons, further studies of good methodological quality are needed.

ABSTRACT CONTEXT AND OBJECTIVE: Despite the high prevalence of vitamin D supplementation, its use remains controversial. The objective of this review was to identify and summarize the evidence from Cochrane systematic reviews regarding vitamin D supplementation for preventing ortreating any clinical condition. DESIGN AND SETTING: Review of systematic reviews, conducted in the Discipline of Evidence-Based Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo. METHODS: A search was conducted to identify all Cochrane systematic reviews that fulfilled the inclusion criteria. Titles and abstracts were screened by two authors. RESULTS: We included 27 Cochrane systematic reviews: 10 assessing use of vitamin D for prevention and 17 for treatment. The reviews found moderate to high quality of evidence regarding the benefit of vitamin D for pregnant women (prevention of adverse events: preterm birth risk [rate ratio, RR 0.36; 95% confidence interval, CI 0.14 to 0.93] and low birthweight risk [RR 0.40; 95% CI 0.24 to 0.67]) and for asthma patients (reduction of severe exacerbations [RR 0.63; 95% CI 0.45 to 0.88]). No benefit was found regarding vitamin D supplementation alone (without calcium) for preventing hip or any new fracture. For all other outcomes assessed under various conditions, the current quality of evidence is low or unknown, and therefore insufficient for any recommendation. CONCLUSION: Based on moderate to high quality of evidence, the Cochrane systematic reviews included here showed that there were some benefits from vitamin D supplementation for pregnant women and asthma patients and no benefits for preventing fractures.