The relationship between study findings and publication outcome in anesthesia research following implementation of mandatory trial registration: A systematic review of publication bias.

Previously, we reviewed 1052 randomized-controlled trial abstracts presented at the American Society of Anesthesiologists annual meetings from 2001-2004. We found significant positive publication bias in the period examined, with the odds ratio for abstracts with positive results proceeding to journal publication over those with null results being 2.01 [95% confidence interval: 1.52, 2.66; P < 0.001]. Mandatory trial registration was introduced in 2005 as a required standard for publication. We sought to examine whether mandatory trial registration has decreased publication bias in the anesthesia and perioperative medicine literature. We reviewed all abstracts from the 2010-2016 American Society of Anesthesiologists meetings that reported on randomized-controlled trials in humans. We scored the result of each abstract as positive or null according to a priori definitions. We systematically searched for any subsequent publication of the studies and calculated the odds ratio for journal publication, comparing positive vs null studies. We compared the odds ratio from the 2010-2016 abstracts (post-mandatory trial registration) with the odds ratio from the 2001-2004 abstracts (pre-mandatory trial registration) as a ratio of odds ratios. We defined a 33% decrease in the odds ratio as significant, corresponding to a new odds ratio of 1.33. We reviewed 9789 abstracts; 1049 met inclusion criteria as randomized-controlled trials, with 542 (51.7%) of the abstracts going on to publication. The odds ratio for abstracts with positive results proceeding to journal publication was 1.28 [95% CI: 0.97, 1.67; P = 0.076]. With adjustment for sample size and abstract quality, the difference in publication rate between positive and null abstracts was statistically significant (odds ratio 1.34; 95% CI: 1.02, 1.76; P = 0.037). The ratio of odds ratios, comparing the odds ratio from the 2010-2016 abstracts (post-mandatory trial registration) to the odds ratio from the 2001-2004 abstracts (pre-mandatory trial registration), was 0.63 (95% CI: 0.43, 0.93); P = 0.021). We present the first study in the anesthesia and perioperative medicine literature that examines and compares publication bias over two discrete periods of time, prior to and after the implementation of mandatory trial registration. Our results suggest that the amount of publication bias has decreased markedly following implementation of mandatory trial registration. However, some positive publication bias in the anesthesia and perioperative medicine literature remains.

Trial registration of abstracts from the American Society of Anesthesiologists Meetings 2010-2016: A review of prospective trial registration and selective outcome reporting.

Mandatory prospective trial registration was introduced in 2005 to reduce publication bias and selective outcome reporting. In this study, we measured the proportion of prospective trial registration in randomized controlled trials in the anesthesia literature after this introduction, discrepancies between these trial protocols and subsequent publications, the association between being prospectively registered and reporting positive or negative results, and between being prospectively registered and achieving publication. We reviewed all abstracts from the American Society of Anesthesiologists annual meetings between 2010-2016 and included randomized controlled trials in humans. The abstract conclusions were scored as positive or negative according to predetermined definitions. We conducted a systematic search for trial registration and subsequent publication. Of the 9789 abstracts reviewed, 1070 abstracts were included. 222 (21%) of these abstracts had undergone prospective trial registration. 168/222 (76%) had a corresponding journal publication. 81(48%) had a major discrepancy between registration and publication. 149 (67%) of the abstracts with registration had positive outcomes compared with 616 (73%) of those without (Odds Ratio 0.77; 95% CI: 0.56 to 1.06; P = 0.105). Abstracts that had been registered were more likely to proceed to publication than those that had not (Odds Ratio 3.82; 95% CI 2.73 to 5.35; P < 0.001). The proportion of randomized controlled trials being prospectively registered in anesthesia remains low. Discrepancies between registry entries and corresponding journal publications are common. There was no association between prospective trial registration and subsequent positive outcomes. There was a strong association between prospective trial registration and the likelihood of progression to journal publication.

Multicenter Survey on Staff Understanding of Preoperative Fasting Guidelines.

PURPOSE: To assess the knowledge of nursing staff regarding pediatric preoperative fasting in a tertiary pediatric center and a general hospital. DESIGN: Anonymous electronic survey with nine questions modified to each institution. METHODS: This was a prospective quantitative study. Nursing staff at a tertiary pediatric center and pediatric nursing staff at a general hospital with pediatric services were eligible for participation. An anonymous electronic survey with nine questions via Survey Monkey was used over a 2-month period. FINDINGS: There were 295 participants from the tertiary pediatric center and 24 from the general hospital which represented 10% of overall nursing staff at the tertiary pediatric center and approximately 50% of pediatric nursing staff at the general hospital. At both the tertiary pediatric center and the general hospital, 50 to 80% of participants correctly answered most questions. More participants were correct for the fasting times for infants less than 6 month of age than for those over 6 months old. For clear fluids, 61 (20.7%) and 13 (4.4%) considered jelly and breast milk as clear fluids respectively at the tertiary pediatric center. CONCLUSIONS: Preoperative fasting continues to be a core area of pediatric care that is not completely understood. Our survey showed that although the majority of staff claim to be able to access the hospital guidelines, knowledge of these guidelines can be improved. In light of ongoing changing evidence, it is clear that education is a key factor in reducing morbidity and improving patient experience related to preoperative fasting.

Serial Observation of Blood Alcohol Concentration post Ethanol Pleurodesis (SOBER) Study: A Prospective Observational Study.

OBJECTIVES: To measure the blood alcohol concentration levels in patients after chemical pleurodesis with ethanol sclerosant via video-assisted thoracoscopic surgery. DESIGN: Prospective observational study. SETTING: Single tertiary university hospital. PARTICIPANTS: Eight patients undergoing chemical pleurodesis with ethanol sclerosant for management of recurrent pneumothoraces or pleural effusions. INTERVENTIONS: After ethics board approval, written informed consent was obtained from 8 patients undergoing chemical pleurodesis with ethanol sclerosant for management of recurrent pneumothoraces or pleural effusions. Five patients received a dose of 100 mL of 70% ethanol/1% iodine, and 3 patients received 30 mL. Blood alcohol concentration measurement was obtained at 30, 60, 90, and 120 minutes after the ethanol was instilled in the interpleural space. The postoperative quality of recovery scale was conducted preoperatively and then at 30 and 60 minutes postoperatively and on postoperative days 1 and 3. MEASUREMENTS AND MAIN RESULTS: The highest observed blood alcohol concentration was recorded at 30 minutes post-instillation of ethanol in all patients. The blood alcohol concentration peak for 75% of patients (6/8) was >0.05 g/dL at 30 minutes post-instillation of ethanol, and for 4 patients (50%), this remained >0.05 g/dL at 60 minutes. The median area under curve of ethanol absorbed was 5.66 g/dL/min (3.24-7.29). CONCLUSIONS: Significant systemic absorption of ethanol can occur after instillation of ethanol sclerosant, which potentially may affect the quality of recovery in patients. Postoperative management of these patients may need to be specifically tailored to take into account these observations.

The relationship between study findings and publication outcome in anesthesia research: a retrospective observational study examining publication bias.

PURPOSE: Many areas of medicine have shown bias towards the publication of studies with positive results. To estimate publication bias in the anesthesia literature, we reviewed all abstracts presented at the American Society of Anesthesiologists (ASA) annual meetings over a four-year period and compared study results (positive vs negative) with publication outcomes. METHODS: This review included all abstracts from the 2001-2004 ASA annual meetings performed as randomized-controlled trials in humans. We scored their outcome results as positive or negative and assessed abstract quality using a 13-point scoring system. We then performed a systematic literature search to identify any subsequent publication of the studies and calculated the relative risk (RR) for journal publication by comparing positive vs negative studies. RESULTS: Of 5,918 abstracts reviewed, 1,052 met inclusion criteria, and 564 (53.6%) of the abstracts proceeded to publication. The RR for abstracts with positive results proceeding to journal publication was 1.42 (95% confidence interval, 1.22 to 1.66; P < 0.001). This result did not change significantly after adjusting for study size and abstract quality score during logistic regression modelling. There was no significant difference in the abstract quality score between positive vs negative studies or between abstracts proceeding vs not proceeding to publication. CONCLUSIONS: Approximately half of the ASA annual meeting abstracts proceed to publication. After adjustment for study quality and size, abstracts with positive results were more likely to proceed to journal publication than those with negative results, suggesting publication bias in the anesthesia literature.

Minimally invasive measurement of cardiac output during surgery and critical care: a meta-analysis of accuracy and precision.

When assessing the accuracy and precision of a new technique for cardiac output measurement, the commonly quoted criterion for acceptability of agreement with a reference standard is that the percentage error (95% limits of agreement/mean cardiac output) should be 30% or less. We reviewed published data on four different minimally invasive methods adapted for use during surgery and critical care: pulse contour techniques, esophageal Doppler, partial carbon dioxide rebreathing, and transthoracic bioimpedance, to assess their bias, precision, and percentage error in agreement with thermodilution. An English language literature search identified published papers since 2000 which examined the agreement in adult patients between bolus thermodilution and each method. For each method a meta-analysis was done using studies in which the first measurement point for each patient could be identified, to obtain a pooled mean bias, precision, and percentage error weighted according to the number of measurements in each study. Forty-seven studies were identified as suitable for inclusion: N studies, n measurements: mean weighted bias [precision, percentage error] were: pulse contour N = 24, n = 714: -0.00 l/min [1.22 l/min, 41.3%]; esophageal Doppler N = 2, n = 57: -0.77 l/min [1.07 l/min, 42.1%]; partial carbon dioxide rebreathing N = 8, n = 167: -0.05 l/min [1.12 l/min, 44.5%]; transthoracic bioimpedance N = 13, n = 435: -0.10 l/min [1.14 l/min, 42.9%]. None of the four methods has achieved agreement with bolus thermodilution which meets the expected 30% limits. The relevance in clinical practice of these arbitrary limits should be reassessed.