Systematic Review and Quantitative Synthesis

Transcription

1 Systematic Review and Quantitative Synthesis Reporting Systematic Reviews and Meta-Analyses Thu 8 March am. Porjai Pattanittum Epidemiology and Biostatistics Department, Public Health Faculty, Khon Kaen University, Thailand pporja@kku.ac.th Outline The PRISMA for Abstracts Checklist 2 1

2 Beller EM, Glasziou PP, Altman DG, et al. PRISMA for Abstracts: Reporting Systematic Reviews in Journal and Conference Abstracts. PLoS Medicine. 2013;10(4):e doi: /journal.pmed

3 The PRISMA for Abstracts Checklist Incorporate the PICOS approach Improve indexing and electronic searching Systematic review and meta-analysis of the diagnostic and therapeutic role of water-soluble contrast agent in adhesive small bowel obstruction. Inhaled corticosteroids vs placebo for preventing COPD [chronic obstructive pulmonary disease] exacerbations: a systematic review and metaregression of randomized controlled trials. 5 The PRISMA for Abstracts Checklist reflect what the review intended to evaluate To assess the effect on survival of supportive care and chemotherapy versus supportive care alone in advanced NSCLC [non-small cell lung cancer] benefit To evaluate the risk of serious asthma-related events among patients treated with formoterol harms The objective of this study was to investigate the predictive value of C-reactive protein in critically ill patients 6 association, predictive value 3

4 The PRISMA for Abstracts Checklist Study eligibility characteristics (+ language of Publication, publication status, year of publication) randomized trials of compression stockings versus no stockings in passengers on flights lasting at least four hours. Trials in which passengers wore a stocking on one leg but not the other, or those comparing stockings and another intervention were also eligible. studies published in English, French, Spanish, Italian and German between 1966 and July, 2008 were included. 7 The PRISMA for Abstracts Checklist listing key databases searched, date range (or date of last search) PubMed, ERIC and Cochrane Reviews databases from January 1980 to November 2007 were searched for studies. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), other trial registries and product information sheets through June

5 The PRISMA for Abstracts Checklist Methods for assessing risk of bias (specify which individual methodological components, provide a description and judgment) Risk of bias was assessed regarding randomisation, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases. 9 The PRISMA for Abstracts Checklist enable readers to gauge the validity and descriptors of applicability of the systematic review s results the participants (e.g., age, severity of disease), range of interventions used (e.g., dose and frequency of drug administration), measurement of outcomes (e.g., follow-up times). We included 22 trials involving 101,507 participants: 11 trials reported on presumptive pneumococcal pneumonia, 19 on all-cause pneumonia and 12 on all-cause mortality. The current 23-valent vaccine was used in 8 trials Eight studies included in this review (n = 586 patients, median PEDro score = 8.0/10) evaluated various parameters, including the duration of patients symptoms (0 12 months), duty cycle (20% and 100%), intensity ( W/cm2), treatment time per session ( minutes), number of treatments (6 39), and total energy applied per treatment (181 8,152 J) 10 5

6 The PRISMA for Abstracts Checklist should not report only those outcomes that have statistically significant or clinically important results (If there are no summary measures, some numerical data may still be given) CRT [cardiac resynchonization therapy] reduced all-cause mortality (6 trials, 4572 participants; risk ratio [RR], 0.83 [95% CI, 0.72 to 0.96]) and heart failure hospitalizations (4 trials, 4349 participants; RR, 0.71 [CI, 0.57 to 0.87]) without improving functional outcomes or quality of life. Eight studies presented adjusted odds ratios, ranging from 0.3 to 0.9, suggesting a reduced likelihood of self-reported sharing of non- N/S [non-needle/syringe] injecting paraphernalia associated with use of NSP [needle and syringe exchange programmes] or SIF [safer injection facilities] 11 The PRISMA for Abstracts Checklist summarise the main outcomes in words (direction; e.g., lower, fewer, reduced; greater, more, increased) and numbers (size of the effect) Radial access reduced major bleeding by 73% compared to femoral access 0.05% vs 2.3%, OR 0.27 [95% CI 0.16, 0.45], P<0.001). Length of hospital and critical care unit stay were both modestly reduced in the tested group compared with the control group, with a mean difference of day (CI, to day) and day (CI, to day), respectively. 12 6

7 The PRISMA for Abstracts Checklist Four potentially eligible trials were not included in the meta-analysis because mortality data by age group were not available. All trials were open label, which may introduce bias. Most of the trials were of 24 weeks duration or less, limiting assessment of long-term safety. Meta-analyses for some outcomes had large statistical heterogeneity or evidence for publication bias. Only 11 trials followed outcomes beyond 12 months. Meta-regression showed that small, poor-quality studies that assessed outcomes soon after radiocontrast administration were more likely to suggest benefit (P<0.05 for all). 13 The PRISMA for Abstracts Checklist + explanation if the conclusions of the review differ substantially from previous SRs + reference(s) if any ongoing studies Travel is associated with a nearly 3-fold higher risk for VTE [venous thromoboembolism], with a dose-response relationship of 18% higher risk for each 2-hour increase in travel duration. 14 7

8 The PRISMA for Abstracts Checklist conflict of interest in respect of the findings of the systematic review This work was supported, in part, by the Program in Reproductive and Adult Endocrinology, NICHD, NIH, Bethesda, MD. The authors have no competing interests to declare. Funding: National Institute for Health Research Programme Grant for Applied Research. 15 The PRISMA for Abstracts Checklist PROSPERO registration: CRD

9 Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: Explanation and elaboration. Vol. 6, PLoS Medicine

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11 21 Incorporate the PICOS approach Improve indexing and electronic searching (not a term of review or overview ) Example Recurrence rates of video-assisted thoracoscopic versus open surgery in the prevention of recurrent pneumothoraces: a systematic review of randomised and non-randomised trials Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis 22 11

12 give readers more complete information and facilitate finding information more easily than unstructured abstracts Background (context, explanation of the importance of review question) Objective (PICOs) Data sources (Sources for searching, any restrictions, dates (start/end)) Study selection (who selected studies using what inclusion criteria) Study appraisal (describe appraisal methods) Data extraction and Data analysis ((in case of meta-analyses) provide numerical results and CI. for the most important outcomes, +no. of studies, no. of participants) Results Limitations (most important weakness of included studies, limitations of the review process) Conclusions +funding, registration information 23 Importance of the review question current state of knowledge, its limitations what the review aims to add (a new systematic review or an update of an existing one) 24 12

13 help define other components of the review process - the eligibility criteria (Item 6) - the search for relevant literature (Items 7 and 8) Example To examine whether topical or intraluminal antibiotics reduce catheter-related bloodstream infection, we reviewed randomized, controlled trials that assessed the efficacy of these antibiotics for primary prophylaxis against catheter-related bloodstream infection and mortality compared with no antibiotic therapy in adults undergoing hemodialysis. 25 help restrict the likelihood of biased post hoc decisions in review methods (e.g. selective outcome reporting) 26 13

14 + language of publication, publication status, year of publication - essential in appraising the validity, applicability, and comprehensiveness of a review - influence the development of the search strategy 27 should also report - who developed and conducted the search - supplementary approaches to identify studies - any attempted to acquire any missing information (who was contacted, what unpublished info. obtained) lets readers assess the currency of the review 28 14

15 - report full electronic search strategy at least one major database (appendix/electronic link) - report any additional limitations (language, date restrictions) - others may access and review them (e.g., replicate them or understand why their review of a similar topic did not identify the same reports) - Future updates 29 - report how authors screened the retrieved records - + the PRISMA flow diagram Example Eligibility assessment [was] performed independently in an unblinded standardized manner by 2 reviewers Disagreements between reviewers were resolved by consensus

16 - pilot, who extracted what data, duplicate approach, independently, how disagreements were resolved - seeking additional info. (how, what info., success in obtaining info. ) - appendix; data extraction form Example We developed a data extraction sheet (based on the Cochrane Consumers and Communication Review Group s data extraction template), pilot-tested it on ten randomly-selected included studies, and refined it accordingly. One review author extracted the following data from included studies and the second author checked the extracted data Disagreements were resolved by discussion between the two review authors; if no agreement could be reached, it was planned a third author would decide. We contacted five authors for further information. All responded and one provided numerical 31 data that had only been presented graphically in the published paper - definitions of variables - report whether some variables were added after the review started (with reasons) - any assumptions authors made about missing or unclear information - appendix; data extraction form 32 16

17 - specify the methodological components - how authors assessed risk of bias (who, duplicate approach, independently, how disagreements were resolved) - seeking additional info. - how their assessments of risk of bias are used subsequently in the data synthesis (e.g. subgroup, sensitivity) Validity of the included studies 33 Example Relative risk of mortality reduction was the primary measure of treatment effect. The meta-analyses were performed by computing relative risks (RRs) using random-effects model. Quantitative analyses were performed on an intention-to-treat basis and were confined to data derived from the period of follow-up. RR and 95% confidence intervals for each side effect (and all side effects) were calculated. The primary outcome measure was the mean difference in log10 HIV-1 viral load comparing zinc supplementation to placebo 34 17

18 - any transformation/imputation (e.g. p-values, t-statistics) - statistical methods (e.g. inverse variance) - model (fixed-, random-effects) 35 report in detail any methods used to investigate possible bias across studies Example For each trial we plotted the effect by the inverse of its standard error. The symmetry of such funnel plots was assessed both visually, and formally with Egger s test, to see if the effect decreased with increasing sample size. We assessed the possibility of publication bias by evaluating a funnel plot of the trial mean differences for asymmetry, which can result from the non publication of small trials with negative results Because graphical evaluation can be subjective, we also conducted an adjusted rank correlation test and a regression asymmetry test as formal statistical tests for publication bias We acknowledge that other factors, such as differences in trial quality or true study heterogeneity, could produce asymmetry in funnel plots

19 Example Sensitivity analyses were pre-specified. The treatment effects were examined according to quality components (concealed treatment allocation, blinding of patients and caregivers, blinded outcome assessment), time to initiation of statins, and the type of statin. One post-hoc sensitivity analysis was conducted including unpublished data from a trial using cerivastatin. 37 a flow diagram 38 19

20 - Forest plot (numerical and graphical display) makes it easier to identify errors 39 Example Mortality data were available for all six trials, randomizing 311 patients and reporting data for 305 patients. There were no deaths reported in the three respiratory syncytial virus/severe bronchiolitis trials; thus our estimate is based on three trials randomizing 232 patients, 64 of whom died. In the pooled analysis, surfactant was associated with significantly lower mortality (relative risk= 0.7, 95% confidence interval = , P =0.04). There was no evidence of heterogeneity (I 2 = 0%)

21 41 (GRADE approach to evaluating the quality of evidence; Summary of findings (SoF) table) Kaner EFS, Beyer FR, Muirhead C, Campbell F, Pienaar ED, Bertholet N, Daeppen JB, Saunders JB, Burnand B. Effectiveness of brief alcohol interventions in primary care populations. Cochrane Database of Systematic Reviews 2018, Issue 2. Art. No.: CD DOI: / CD pub

22 - validity (risk of bias) - reporting of included studies - limitation of review process - generalizability

23 References Beller EM, Glasziou PP, Altman DG, et al. PRISMA for Abstracts: Reporting Systematic Reviews in Journal and Conference Abstracts. PLoS Medicine. 2013;10(4):e doi: /journal.pmed Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: Explanation and elaboration. Vol. 6, PLoS Medicine