The obstetrical research landscape: a cross-sectional analysis of clinical trials from 2007-2020

Background

Obstetrical complications affect more than a third of women globally, but are underrepresented in clinical research. Little is known about the comprehensive obstetrical clinical trial landscape, how it compares with other fields, or factors associated with the successful completion of obstetrical trials.

Objective

This study aimed to characterize obstetrical clinical trials registered on ClinicalTrials.gov with the primary objective of identifying features associated with early discontinuation and results reporting.

Study Design

This is a cross-sectional study with descriptive, logistic regression and Cox regression analyses of clinical trials registered on ClinicalTrials.gov. Our primary exposure variables were trial focus (obstetrical or nonobstetrical) and trial funding (industry, United States government, or academic). We conducted additional exploratory analyses of other trial features including design, enrollment, and therapeutic focus. We examined the associations of exposure variables and other trial features with 2 primary outcomes: early discontinuation and results reporting.

Results

We downloaded data for all studies (N=332,417) registered on ClinicalTrials.gov from October 1, 2007, to March 9, 2020, from the Aggregate Analysis of ClinicalTrials.gov database. We excluded studies with a noninterventional design (n=63,697) and those registered before October 1, 2007 (n=45,209). A total of 4276 obstetrical trials (1.9%) (ie, interventional studies) and 219,235 nonobstetric trials (98.1%) were compared. Among all trials, 2.8% of academic-funded trials, 1.9% of United States government–funded trials, and 0.4% of industry-funded trials focused on obstetrics. The quantity of obstetrical trials increased over time (10.8% annual growth rate). Compared with nonobstetrical trials, obstetrical trials had a greater risk of early discontinuation (adjusted hazard ratio, 1.40; 95% confidence interval, 1.21–1.62; P<.0001) and similar odds of results reporting (adjusted odds ratio, 0.89; 95% confidence interval, 0.72–1.10; P=.19). Among obstetrical trials funders after controlling for confounding variables, United States government–funded trials were at the lowest risk of early discontinuation (United States government, adjusted hazard ratio, 0.23; 95% confidence interval, 0.07–0.69; P=.009; industry reference; academic, adjusted hazard ratio, 1.04; 95% confidence interval, 0.62–1.74; P=.88). Academic-funded trials had the lowest odds of results reporting after controlling for confounding variables (academic institutions, adjusted odds ratio, 0.39; 95% confidence interval, 0.22–0.68; P=.0009; industry reference; United States government, adjusted odds ratio, 1.06; 95% confidence interval, 0.53–2.09; P=.87).

Conclusion

Obstetrical trials represent only 1.9% of all clinical trials in ClinicalTrials.gov and have comparatively poor completion. All stakeholders should commit to increasing the number of obstetrical trials and improving their completion and dissemination to ensure clinical research reflects the obstetrical burden of disease and advances maternal health.

Double-balloon enteroscopy: Experience with an innovative endoscopic technique at the Hospital Universitario de la Fundación Santa Fe de Bogotá

INTRODUCTION AND AIMS

Double-balloon enteroscopy is a recently introduced endoscopic method that enables complete visualization of the small bowel, as well as biopsy sampling and therapeutic interventions in that part of the intestine. The aim of the present study was to describe the experience acquired at our hospital to determine the characteristics of the patients that underwent the procedure.

MATERIALS AND METHODS

A descriptive, cross-sectional study was conducted on all patients above 18 years of age admitted to the Hospital Universitario de la Fundación Santa Fe de Bogotá for double-balloon enteroscopy, within the time frame of January 2013 to December 2017.

RESULTS

The study sample included 93 procedures in 73 patients. Mean patient age was 57.91 years, with a similar number of men and women. There were no severe complications. The most frequent indication for the enteroscopy was gastrointestinal bleeding (overt or occult), presenting in 49.46% of the patients, followed by chronic diarrhea (16.13%). Video capsule endoscopy was the previous study most frequently performed (53.76%). Anterograde double-balloon enteroscopy was carried out in 49 patients and 44 patients underwent the retrograde procedure. A total of 86.02% of the enteroscopies were diagnostic procedures and 13.98% were therapeutic. Normal enteroscopy was the most frequent finding (59.68%), followed by the presence of ulcers (15.05%).

CONCLUSIONS

Our results were similar to those reported worldwide, with respect to indications, insertion route, and insertion depth, and there were no severe complications.

Tolerance and diagnostic accuracy of an abbreviated adenosine infusion for myocardial scintigraphy: a randomized, prospective study

BACKGROUND

The objectives of this study were 2-fold: (1) to determine the tolerance of adenosine perfusion tomography with the use of an abbreviated (3-minute) infusion in comparison to the standard (6-minute) infusion, and (2) to assess the relative diagnostic accuracy of a 3-minute adenosine infusion in patients referred for arteriography. An abbreviated adenosine infusion may decrease the frequency and duration of side effects and be a more cost-effective alternative.

METHODS AND RESULTS

We prospectively randomized 599 patients undergoing adenosine myocardial perfusion tomography to either a 3-minute or 6-minute adenosine infusion at 140 microg/kg per minute. Among the 599 enrolled patients, 142 subsequently underwent coronary angiography. Patients randomized to the 3-minute adenosine infusion tolerated the procedure better than those randomized to the standard infusion (P <.01). Flushing, headache, neck pain, and atrioventricular block were all significantly less frequent (P <.01) with the abbreviated infusion. Moreover, patients receiving the abbreviated infusion had less hypotension and tachycardia (P <.05). The sensitivity of the test for detection of coronary artery disease was 88% for both the 3- and 6-minute infusions. In patients with abnormal scan results, perfusion defect size was slightly larger in those receiving a 6-minute infusion versus those receiving a 3-minute infusion (P =.05).

CONCLUSIONS

An abbreviated 3-minute adenosine infusion, in combination with perfusion tomography, has similar sensitivity for detection of coronary artery disease and is better tolerated than the standard 6-minute infusion.

Dysregulation of melatonin metabolism in chronic renal insufficiency: role of erythropoietin-deficiency anemia

Chronic renal failure (CRF) is associated with a variety of neurological and endocrine disorders. In this study, we examined the effect of CRF and the associated anemia on circadian variation of pineal hormone, melatonin. Animals were studied six weeks after 5/6 nephrectomy (CRF group, N = 26) or sham operation (control group, N = 28). A group of erythropoietin-treated CRF animals (CRF/EPO, N = 6) was included to discern the possible role of EPO-deficiency anemia. Compared with the normal control group, the CRF group showed a marked attenuation of the nocturnal surge in serum melatonin concentration. In addition, pineal gland melatonin content measured after a 12-hour dark cycle (< or = 2 lux) was significantly depressed in the CRF group when compared to that obtained in the control group. However, the CRF animals exhibited appropriate suppression of serum concentration and pineal tissue melatonin content in response to bright light (> or = 2500 lux). Administration of EPO led to correction of the CRF anemia and a marked improvement of the defective nocturnal rhythm of serum melatonin. Based on our results, experimental CRF is associated with a marked attenuation of the normal nocturnal surge of serum melatonin concentration. Regular EPO administration results in the correction of anemia and substantial reversal of this abnormality suggesting the partial role of EPO deficiency. The possible role of melatonin dysregulation in the pathophysiology of CRF and the potential value of melatonin supplementation in this condition is uncertain and awaits future investigations.

Pancreatic anatomy in children: emphasis on its importance to pancreatectomy

The literature is riddled with misconceptions concerning the landmarks and the actual amount of pancreatic tissue resected in "subtotal" 60% to 90% pancreatectomies. In order to clarify the surgical anatomy of the pancreas, 13 autopsy specimens from children aged 2 days to 15 years were carefully examined. Pancreata were serially removed from the in situ position in four sections and weighed. Section 1 included pancreatic tissue from the tail to the left of the superior mesenteric vessels (SMV); section 2 included all tissue from the tail to the right of the SMV; section 3 contained tissue up to the left of the pancreaticoduodenal vessels in the head of the pancreas; and section 4 included the remainder of the pancreatic head within the duodenal sweep and the uncinate process. Results showed that section 1 weighed 47.5% +/- 9.7% (mean +/- SD) of the total pancreatic weight with a wide range of 32.3% to 67.3%; section 2 weighed 53.5% +/- 9.0% (range, 38.7% to 72.2%); section 3 weighed 69.1% +/- 15.6% (range, 43.5% to 95.8%); and section 4 weighed 31.6% +/- 14.6% (range, 4.2% to 56.5%). As noted, pancreatic anatomy was extremely variable in relation to the percent of tissue to either side of the SMV and the proportion of tissue contained within the uncinate process. Resections historically reported to result in a "75%" pancreatectomy (section 2) were demonstrated to contain a mean of only 53.5% +/- 9.0% of the pancreas. Less tissue than expected would be resected by using the SMV as landmarks for a 75% resection. The wide variation in anatomy also has important clinical implications in performing "subtotal" pancreatectomies in infants with nesidioblastosis in whom the amount of tissue resected is critical to the patient's postoperative clinical course. This study demonstrates that a subtotal pancreatectomy should not be based upon the presumed relation of the pancreatic substance to the SMV. The entire gland including the uncinate process should be visualized at operation in order that a proper pancreatectomy is performed.