Frequency of use and adequacy of Cochrane risk of bias tool 2 in non-Cochrane systematic reviews published in 2020: Meta-research study

Risk of bias (RoB) assessment is essential to the systematic review methodology. The new version of the Cochrane RoB tool for randomized trials (RoB 2) was published in 2019 to address limitations identified since the first version of the tool was published in 2008 and to increase the reliability of assessments. This study analyzed the frequency of usage of the RoB 2 and the adequacy of reporting the RoB 2 assessments in non-Cochrane reviews published in 2020. This meta-research study included non-Cochrane systematic reviews of interventions published in 2020. For the reviews that used the RoB 2 tool, we analyzed the reporting of the RoB 2 assessment. Among 3880 included reviews, the Cochrane RoB 1 tool was the most frequently used (N = 2228; 57.4%), followed by the Cochrane RoB 2 tool (N = 267; 6.9%). From 267 reviews that reported using the RoB 2 tool, 213 (79.8%) actually used it. In 26 (12.2%) reviews, erroneous statements were used to indicate the RoB 2 assessment. Only 20 (9.4%) reviews presented a complete RoB 2 assessment with a detailed table of answers to all signaling questions. The judgment of risk of bias by the RoB 2 tool was not justified by a comment in 158 (74.2%) reviews. Only in 33 (14.5%) of reviews the judgment in all domains was justified in the accompanying comment. In most reviews (81.7%), the RoB was inadequately assessed at the study level. In conclusion, the majority of non-Cochrane reviews published in 2020 still used the Cochrane RoB 1 tool. Many reviews used the RoB 2 tool inadequately. Further studies about the uptake and the use of the RoB 2 tool are needed.

Oncological aspect of incidental appendectomy with regard to histopathological findings: A retrospective cohort study

INTRODUCTION

The aim of this retrospective cohort study was to describe the findings on histopathological examination of removed, macroscopically non-diseased, vermicular appendix during another primary surgical procedure (incidental appendectomy (IA)). Previous studies disapproved IA but were based on the possibility of complicated appendicitis. We observed the prevalence of neoplasms of the appendix in IA versus the appendectomy performed due to acute appendicitis (AA).

METHODS

The database of histopathology reports of the Surgery Department, University Hospital of Split was reviewed in the period from January 1, 2017, to December 31, 2021. A total of 2832 histopathology reports were reviewed.

RESULTS

There was no difference in gender distribution between these two groups, but AA had a statistically significantly lower median patient age compared to the group IA (40 vs. 68 years; P < 0.001). In the AA group, there were 84.5% acute appendicitis, 11.1% normal appendiceal reports, 3.2% appendiceal neoplasms, and 1.2% other pathologies. The group IA had 89.5% normal findings of the appendix, 7.2% appendiceal neoplasms, and 0.5% other pathology. The difference in neoplasm prevalence between IA and AA groups was 4.0% (95%CI: 2.2 to 5.8), P < 0.001. The number of incidental appendectomies needed to detect one neoplasm of the appendix is 25.

CONCLUSION

Incidental appendectomies in patients undergoing abdominal surgery revealed a relatively high prevalence of appendiceal neoplasms above the age of 60 years. Prospective studies about incidental appendectomies, their clinical consequences, and impact on prognosis should be performed to define the value of incidental appendectomy in those patients.

A novel Appendicitis TriMOdal prediction Score (ATMOS) for acute appendicitis in pregnancy: a retrospective observational study

Several scoring systems exist for the management of acute appendicitis (AA) during pregnancy. However, the systems are based on the nonpregnant adult population. The aim of this study was to create a highly accurate scoring system that can be applied to pregnant women and to compare it to the most commonly used scores in general population and pregnant women. The creation and subsequent implementation of a highly accurate score system could shorten the diagnostic period and minimize the use of (ionizing) diagnostic imaging allowing the selection of the best treatment approach in pregnant patients with acute appendicitis. A single-center, retrospective cohort observational study was conducted at the University Hospital Centre Zagreb, Zagreb, Croatia. Data were extracted from medical records of pregnant patients with suspected AA from January 2010 to December 2020. A total of 59 pregnant patients diagnosed with AA during pregnancy were identified, 41 were treated surgically, and 18 had non-surgical management. The main objective of our study was the detection of predictive factors of AA during pregnancy. Anorexia, pain migration to the right lower quadrant, rebound pain, axillary temperature over 37.3 °C, CRP/platelet ratio > 0.0422, neutrophil/lymphocyte ratio > 7.182, and ultrasonic signs of AA were scored. Scoring in Appendicitis TriMOdal Score (ATMOS) consists of positive clinical parameter, each bringing 1 point and other parameters mentioned above that bring 2 points each. The score ranges from 0 to 10. Our model of ATMOS yields a high area under the receiver-operating characteristic curve of 0.963. The positive likelihood ratio is 9.97 (95% CI 2.64-38.00), and the negative likelihood ratio is 0.1 (95% CI 0.03-0.31), meaning that 94% of cases with ATMOS > 4 have AA, while less than 13% with an ATMOS ≤ 4 have the diagnosis of AA. The potential of ATMOS differentiating AA during pregnancy was demonstrated. Future prospective, randomized trials are needed to evaluate its accuracy and whether it should be used instead of Alvarado or Tzanakis scores in clinical decision-making.Trial registration number ClinicalTrials.gov-NCT05202483. Date of registration: January 21, 2022.

Enhanced access to recommendations from the Cochrane Handbook for improving authors' judgments about risk of bias: A randomized controlled trial

This randomized controlled trial (RCT) aimed to test the efficacy of enhanced access to Cochrane Handbook (Handbook) recommendations for judging the 2011 Cochrane risk of bias (RoB) domains for improving the adequacy of RoB judgments. Parallel-group RCT with a 1:1 allocation ratio (N = 2271 per group) was conducted. Eligible participants were corresponding authors of all published Cochrane reviews and protocols. After allocation by a random number generator, participants received 20 scenarios for assessing RoB. The intervention group was shown tables from the Handbook with instructions for assessing 2011 RoB tool together with scenarios they were supposed to assess-enhanced access to the Handbook. The control group was shown only a general link to the Handbook. The primary outcome was the proportion of participants that made an adequate judgment of RoB scenarios for analyzed domains. There were 240 responses out of 2020 delivered e-mail invitations in the intervention and 197/2254 in the control group. Only five participants from the intervention group judged RoB adequately in all the 20 scenarios and no one in the control group. The proportion of participants who adequately assessed all the scenarios within a domain was significantly higher in the intervention than in the control group. The frequency of adequate RoB judgments was 7.1% (95% CI: 5.0-9.3%, p < 0.001) higher in the intervention group (76.2%) than in the control group (69.0%). The enhanced access yields more adequate RoB assessments and could be incorporated in software supporting the RoB tool.

Predictive value of abdominal drain amylase for postoperative pancreatic fistula following gastric resection: A systematic review and meta-analysis

BACKGROUND

Radical dissection of lymph nodes, accompanying gastric cancer resection, can lead to collateral damage to the pancreas and development of postoperative pancreatic fistula (POPF).

METHODS

We searched the Cochrane Library, MEDLINE, Embase, and Web of Science up to April 21, 2020, to identify studies documenting the value of abdominal drain amylase level (d-AMY) on postoperative day 1 (POD1) as a predictor of POPF after gastric surgery. The quality of selected studies was assessed using the QUADAS-2 tool. The diagnostic value of d-AMY on POD1 for prediction of POPF was first assessed by calculation of pooled estimates of sensitivity, specificity, likelihood ratios (LR), and the diagnostic odds ratio (DOR). Secondly, the accuracy was further demonstrated graphically with the hierarchical summary receiver operating curve (hSROC). PROSPERO registration number: CRD42020181145.

RESULTS

DOR of nine studies (cases n = 1856) observing the occurrence of POPF after measurement of d-AMY on POD1 was 18.7 (95%CI: 10.0, 34.8), and the area under hSROC was 0.88 ± 0.02. The pooled sensitivity was 0.74 (95%CI: 0.66, 0.81) and specificity 0.84 (95%CI: 0.82, 0.86). The negative LR was at the lowest point of 0.16 (95%CI: 0.07, 0.37) at the cutoff value for d-AMY of 941 IU/L, while the positive LR ranged from 4.4 (cutoff 2119 IU/L) to 6.2 (cutoff 5000 IU/L).

CONCLUSION

d-AMY on POD1 can be used as an accurate and non-invasive predictor of POPF in the earliest stage of postoperative course following gastric cancer resection; value ≤ 941 IU/L warrants early drain removal and low probability of POPF (any grade).

Assessing risk of bias judgments for blinding of outcome assessors in Cochrane reviews

Aim: Adequate judging of risk of bias (RoB) for blinding of outcome assessors (detection bias) is important for supporting highest level of evidence. Materials & methods: Judgments and supporting comments for detection bias were retrieved from RoB tables reported in Cochrane reviews. We categorized comments, and then compared judgment and supporting comment with instructions from the Cochrane Handbook. Results: We analyzed 8656 judgments for detection bias from 7626 trials included in 575 reviews. Overall, 1909 judgments (22%) were not in line with the Cochrane Handbook. In 9% of trials, the authors split the detection bias domain according to outcomes. Here, prevalence of inadequate judgments was 19%. Conclusion: Interventions to improve RoB assessments in systematic reviews should be explored.

Cochrane risk of bias tool was used inadequately in the majority of non-Cochrane systematic reviews

OBJECTIVES

To analyze how many non-Cochrane systematic reviews (NCSRs) used Cochrane's risk of bias (RoB) tool, domains they used, and whether judgments and comments about RoB were in line with Cochrane Handbook.

METHODS

This was a methodological (research-on-research) study. We retrieved NCSRs from PubMed, extracted information about methods used for RoB assessment, and if they used 2011 Cochrane RoB tool, we analyzed their RoB methods and compared them with Cochrane Handbook guidance.

RESULTS

We included 508 NCSRs; 431 (85%) reported they analyzed RoB, and 269 (53%) used Cochrane RoB tool. Only 16 of those 269 (5.9%) reported both a judgment and a supporting comment in the Cochrane RoB table in the manuscript (N = 4) or in a supplementary file (N = 12). Fifteen reviews, with 158 included trials, used judgments low/high/unclear; 41% of analyzed available judgments were inadequate, either because judgment was not in line with comment or comment was missing.

CONCLUSIONS

Most NCSRs use Cochrane RoB tool to assess RoB, but most of them reported it incompletely, with high prevalence of inadequate judgments. Authors, editors, and peer-reviewers should make an effort to improve completeness and adequacy of Cochrane RoB assessment in non-Cochrane reviews.

Risk of bias judgments for random sequence generation in Cochrane systematic reviews were frequently not in line with Cochrane Handbook

BACKGROUND

Assessing the risk of bias (RoB) in included studies is one of the key methodological aspects of systematic reviews. Cochrane systematic reviews appraise RoB of randomised controlled trials (RCTs) with the Cochrane RoB tool. Detailed instructions for using the Cochrane RoB tool are provided in the Cochrane Handbook for Systematic Reviews of Interventions (The Cochrane Handbook). The purpose of this study was to analyse whether Cochrane authors use adequate judgments about the RoB for random sequence generation of RCTs included in Cochrane reviews.

METHODS

We extracted authors' judgments (high, low or unclear RoB) and supports for judgments (comments accompanying judgments which explain the rationale for a judgment) for random sequence generation of included RCTs from RoB tables of Cochrane reviews using automated data scraping. We categorised all supporting comments, analysed the number and type of various supporting comments and assessed adequacy of RoB judgment for randomisation in line with recommendations from the Cochrane Handbook.

RESULTS

We analysed 10,103 RCTs that were included in 704 Cochrane reviews. For 5,706 RCTs, randomisation was not described, but for the remaining RCTs, it was indicated that randomisation was performed using computer/software/internet (N = 2,850), random number table (N = 883), mechanical method (N = 359) or it was incomplete/inappropriate (N = 305). Overall, 1,220/10,103 trials (12%) did not have a RoB judgment in line with Cochrane Handbook guidance about randomisation. The highest proportion of misjudgements was found for trials with high RoB (28%), followed by those with low (20%) or unclear (3%). Therefore, one in eight judgments for the analysed domain in Cochrane reviews was not in line with Cochrane Handbook, and one in four if the judgment was "high risk".

CONCLUSION

Authors of Cochrane reviews often make judgments about the RoB related to random sequence generation that are not in line with instructions given in the Cochrane Handbook, which compromises the reliability of the systematic reviews. Our results can help authors of both Cochrane and non-Cochrane reviews which use Cochrane RoB tool to avoid making common mistakes when assessing RoB in included trials.

Investigation of spermatozoa and seminal plasma by fourier transform infrared spectroscopy

Fourier transform infrared (FT-IR) spectra of human spermatozoa and seminal plasma were recorded and analyzed. The procedure that was established for sample preparation enabled acquisition of reproducible spectra. The parameter I(1087)/I(966) for controlling spectra reproducibility was defined. The assignment of bands was carried out using an empirical approach and the origin of the "sperm specific doublet", the bands at 968 cm(-1) and 981 cm(-1), was determined. The principal component regression (PCR) algorithm was used to define the specific spectral regions correlating to characteristics of spermatozoa, such as concentration, straight-line velocity (VSL), and beat cross frequency (BCF). Then, simple spectral parameters, such as band intensities and band ratios, were tested to determine which one best correlates to characteristics of spermatozoa. The region of the amide I band, between 1700 cm(-1) and 1590 cm(-1), was defined as a specific spectral region that correlates to the concentration of spermatozoa. The parameter that gave the linear dependence to the concentration of spermatozoa was the intensity of the amide I band. For VSL, the bands between 1119 cm(-1) and 943 cm(-1) were defined as the specific spectral region. The relative amount of nucleic acids with respect to proteins showed linear dependence on the straight-line velocity of spermatozoa. BCF showed the best correlation to the bands between 3678 cm(-1) and 2749 cm(-1), which largely represent lipids and proteins. These results suggest that FT-IR spectroscopy can serve as an adjunct to conventional histopathology studies.