Instruments assessing risk of bias of randomized trials frequently included items that are not addressing risk of bias issues

Proton-Pump Inhibitors to Prevent Gastrointestinal Bleeding - An Updated Meta-Analysis

BACKGROUND

The goal of this systematic review was to examine the efficacy and safety of proton-pump inhibitors for stress ulcer prophylaxis in critically ill patients.

METHODS

We included randomized trials comparing proton-pump inhibitors versus placebo or no prophylaxis in critically ill adults, performed meta-analyses, and assessed certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations approach. To explore the effect of proton-pump inhibitors on mortality based on disease severity, a subgroup analysis was conducted combining within-trial subgroup data from the two largest trials and assessed credibility using the Instrument for Assessing the Credibility of Effect Modification Analyses.

RESULTS

Twelve trials that enrolled 9533 patients were included. Proton-pump inhibitors were associated with a reduced incidence of clinically important upper gastrointestinal bleeding (relative risk [RR], 0.51 [95% confidence interval (CI), 0.34 to 0.76]; high certainty evidence). Proton-pump inhibitors may have little or no effect on mortality (RR, 0.99 [95% CI, 0.93 to 1.05]; low certainty). Within-trial subgroup analysis with intermediate credibility suggested that the effect of proton-pump inhibitors on mortality may differ based on disease severity. Subgroup results raise the possibility that proton-pump inhibitors may decrease 90-day mortality in less severely ill patients (RR, 0.89; 95% CI, 0.80 to 0.98) and may increase mortality in more severely ill patients (RR, 1.08; 95% CI, 0.96 to 1.20]. Proton-pump inhibitors may have no effect on pneumonia and little or no effect on Clostridioides difficile infection (low certainty).

CONCLUSIONS

High certainty evidence supports the association of proton-pump inhibitors with decreased upper gastrointestinal bleeding. Proton-pump inhibitors may have little or no effect on mortality, although a decrease in mortality in less severely ill patients and an increase in mortality in more severely ill patients remain possible. (PROSPERO number CRD42023461695.).

Proton pump inhibitors for gastrointestinal bleeding prophylaxis in critically ill patients: A systematic review protocol

BACKGROUND

Proton pump inhibitors (PPIs) are the most commonly prescribed drugs for preventing upper gastrointestinal bleeding in critically ill patients. However, concerns have arisen about the possible harms of using PPIs, including potentially increased risk of pneumonia, Clostridioides difficile infection, and more seriously, an increased risk of death in the most severely ill patients. Triggered by the REVISE trial, which is a forthcoming large randomized trial comparing pantoprazole to placebo in invasively mechanically ventilated patients, we will conduct this systematic review to evaluate the efficacy and safety of PPIs versus no prophylaxis for critically ill patients.

METHODS

We will systematically search randomized trials that compared gastrointestinal bleeding prophylaxis with PPIs versus placebo or no prophylaxis in adults in the intensive care unit (ICU). Pairs of reviewers will independently screen the literature, and for those eligible trials, extract data and assess risk of bias. We will perform meta-analyses using a random-effects model, and calculate relative risks for dichotomous outcomes and mean differences for continuous outcomes, and the associated 95% confidence intervals. We will conduct subgroup analysis to explore whether the impact of PPIs on mortality differs in more and less severely ill patients. We will assess certainty of evidence using the GRADE approach.

DISCUSSION

This systematic review will provide the most up-to-date evidence regarding the merits and limitations of stress ulcer prophylaxis with PPIs in critically ill patients in contemporary practice.

Author instructions in biomedical journals infrequently address systematic review reporting and methodology: a cross-sectional study

OBJECTIVES

We aimed to analyze how instructions for authors in journals indexed in MEDLINE address systematic review (SR) reporting and methodology.

STUDY DESIGN AND SETTING

We analyzed instructions for authors in 20% of MEDLINE-indexed journals listed in the online catalog of the National Library of Medicine on July 27, 2021. We extracted data only from the instructions published in English. We extracted data on the existence of instructions for reporting and methodology of SRs.

RESULTS

Instructions from 1,237 journals mentioned SRs in 45% (n = 560) of the cases. Systematic review (SR) registration was mentioned in 104/1,237 (8%) of instructions. Guidelines for reporting SR protocols were found in 155/1,237 (13%) of instructions. Guidelines for reporting SRs were explicitly mentioned in 461/1,237 (37%), whereas the EQUATOR (Enhancing the Quality and Transparency of Health Research) network was referred to in 474/1,237 (38%) of instructions. Less than 2% (n = 20) of instructions mentioned risk of bias and meta-analyses; less than 1% mentioned certainty of evidence assessment, methodological expectations, updating of SRs, overviews of SRs, or scoping reviews.

CONCLUSION

Journals indexed in MEDLINE rarely provide instructions for authors regarding SR reporting and methodology. Such instructions could potentially raise authors' awareness and improve how SRs are prepared and reported.

Compelling evidence from meta-epidemiological studies demonstrates overestimation of effects in randomized trials that fail to optimize randomization and blind patients and outcome assessors

OBJECTIVES

To investigate the impact of potential risk of bias elements on effect estimates in randomized trials.

STUDY DESIGN AND SETTING

We conducted a systematic survey of meta-epidemiological studies examining the influence of potential risk of bias elements on effect estimates in randomized trials. We included only meta-epidemiological studies that either preserved the clustering of trials within meta-analyses (compared effect estimates between trials with and without the potential risk of bias element within each meta-analysis, then combined across meta-analyses; between-trial comparisons), or preserved the clustering of substudies within trials (compared effect estimates between substudies with and without the element, then combined across trials; within-trial comparisons). Separately for studies based on between- and within-trial comparisons, we extracted ratios of odds ratios (RORs) from each study and combined them using a random-effects model. We made overall inferences and assessed certainty of evidence based on Grading of Recommendations, Assessment, development, and Evaluation and Instrument to assess the Credibility of Effect Modification Analyses.

RESULTS

Forty-one meta-epidemiological studies (34 of between-, 7 of within-trial comparisons) proved eligible. Inadequate random sequence generation (ROR 0.94, 95% confidence interval [CI] 0.90-0.97) and allocation concealment (ROR 0.92, 95% CI 0.88-0.97) probably lead to effect overestimation (moderate certainty). Lack of patients blinding probably overestimates effects for patient-reported outcomes (ROR 0.36, 95% CI 0.28-0.48; moderate certainty). Lack of blinding of outcome assessors results in effect overestimation for subjective outcomes (ROR 0.69, 95% CI 0.51-0.93; high certainty). The impact of patients or outcome assessors blinding on other outcomes, and the impact of blinding of health-care providers, data collectors, or data analysts, remain uncertain. Trials stopped early for benefit probably overestimate effects (moderate certainty). Trials with imbalanced cointerventions may overestimate effects, while trials with missing outcome data may underestimate effects (low certainty). Influence of baseline imbalance, compliance, selective reporting, and intention-to-treat analysis remain uncertain.

CONCLUSION

Failure to ensure random sequence generation or adequate allocation concealment probably results in modest overestimates of effects. Lack of patients blinding probably leads to substantial overestimates of effects for patient-reported outcomes. Lack of blinding of outcome assessors results in substantial effect overestimation for subjective outcomes. For other elements, though evidence for consistent systematic overestimate of effect remains limited, failure to implement these safeguards may still introduce important bias.

Exercise for sarcopenia in older people: A systematic review and network meta-analysis

BACKGROUND

Sarcopenia is a serious public health concern among older adults worldwide. Exercise is the most common intervention for sarcopenia. This study aimed to compare the effectiveness of different exercise types for older adults with sarcopenia.

METHODS

Randomized controlled trials (RCTs) that examined the effectiveness of exercise interventions on patient-important outcomes for older adults with sarcopenia were eligible. We systematically searched MEDLINE, Embase and Cochrane Central Register of Controlled Trials via Ovid until 3 June 2022. We used frequentist random-effects network meta-analyses to summarize the evidence and applied the Grading of Recommendations, Assessment, Development, and Evaluations framework to rate the certainty of evidence.

RESULTS

Our search identified 5988 citations, of which 42 RCTs proved eligible with 3728 participants with sarcopenia (median age: 72.9 years, female: 73.3%) with a median follow-up of 12 weeks. We are interested in patient-important outcomes that include mortality, quality of life, muscle strength and physical function measures. High or moderate certainty evidence suggested that resistance exercise with or without nutrition and the combination of resistance exercise with aerobic and balance training were the most effective interventions for improving quality of life compared to usual care (standardized mean difference from 0.68 to 1.11). Moderate certainty evidence showed that resistance and balance exercise plus nutrition (mean difference [MD]: 4.19 kg) was the most effective for improving handgrip strength (minimally important difference [MID]: 5 kg). Resistance and balance exercise with or without nutrition (MD: 0.16 m/s, moderate) were the most effective for improving physical function measured by usual gait speed (MID: 0.1 m/s). Moderate certainty evidence showed that resistance and balance exercise (MD: 1.85 s) was intermediately effective for improving physical function measured by timed up and go test (MID: 2.1 s). High certainty evidence showed that resistance and aerobic, or resistance and balance, or resistance and aerobic exercise plus nutrition (MD from 1.72 to 2.28 s) were intermediately effective for improving physical function measured by the five-repetition chair stand test (MID: 2.3 s).

CONCLUSIONS

In older adults with sarcopenia, high or moderate certainty evidence showed that resistance exercise with or without nutrition and the combination of resistance exercise with aerobic and balance training were the most effective interventions for improving quality of life. Adding nutritional interventions to exercise had a larger effect on handgrip strength than exercise alone while showing a similar effect on other physical function measures.

Methodological quality assessment should move beyond design specificity

OBJECTIVE

This study aimed to assess the utility of a unified tool (MASTER) for bias assessment against design-specific tools in terms of content and coverage.

METHODS

Each of the safeguards in the design-specific tools was compared and matched to safeguards in the unified MASTER scale. The design-specific tools were the JBI, Scottish Intercollegiate Guidelines Network (SIGN), and the Newcastle-Ottawa Scale (NOS) tools for analytic study designs. Duplicates, safeguards that could not be mapped to the MASTER scale, and items not applicable as safeguards against bias were flagged and described.

RESULTS

Many safeguards across the JBI, SIGN, and NOS tools were common, with a minimum of 10 to a maximum of 23 unique safeguards across various tools. These 3 design-specific toolsets were missing 14 to 26 safeguards from the MASTER scale. The MASTER scale had complete coverage of safeguards within the 3 toolsets for analytic designs.

CONCLUSIONS

The MASTER scale provides a unified framework for bias assessment of analytic study designs, has good coverage, avoids duplication, has less redundancy, and is more convenient when used for methodological quality assessment in evidence synthesis. It also allows assessment across designs that cannot be done using a design-specific tool.