Representing narrative evidence as clinical evidence logic statements

Objective

Clinical evidence logic statements (CELS) are shareable knowledge artifacts in a semistructured “If-Then” format that can be used for clinical decision support systems. This project aimed to assess factors facilitating CELS representation.

Materials and Methods

We described CELS representation of clinical evidence. We assessed factors that facilitate representation, including authoring instruction, evidence structure, and educational level of CELS authors. Five researchers were tasked with representing CELS from published evidence. Represented CELS were compared with the formal representation. After an authoring instruction intervention, the same researchers were asked to represent the same CELS and accuracy was compared with that preintervention using McNemar’s test. Moreover, CELS representation accuracy was compared between evidence that is structured versus semistructured, and between CELS authored by specialty-trained versus nonspecialty-trained researchers, using χ2 analysis.

Results

261 CELS were represented from 10 different pieces of published evidence by the researchers pre- and postintervention. CELS representation accuracy significantly increased post-intervention, from 20/261 (8%) to 63/261 (24%, P value < .00001). More CELS were assigned for representation with 379 total CELS subsequently included in the analysis (278 structured and 101 semistructured) postintervention. Representing CELS from structured evidence was associated with significantly higher CELS representation accuracy (P = .002), as well as CELS representation by specialty-trained authors (P = .0004).

Discussion

CELS represented from structured evidence had a higher representation accuracy compared with semistructured evidence. Similarly, specialty-trained authors had higher accuracy when representing structured evidence.

Conclusion

Authoring instructions significantly improved CELS representation with a 3-fold increase in accuracy. However, CELS representation remains a challenging task.

Variation in Radiologists' Follow-Up Imaging Recommendations for Small Cystic Pancreatic Lesions

OBJECTIVE

This study aimed to determine the incidence, identify imaging and patient factors, and measure individual radiologist variation associated with follow-up recommendations for small focal cystic pancreatic lesions (FCPLs), a common incidental imaging finding.

METHODS

This institutional review board-approved retrospective study analyzed 146,709 reports from abdominal CTs and MRIs performed in a large academic hospital from July 1, 2016, to June 30, 2018. A trained natural language processing tool identified 4,345 reports with FCPLs, which were manually reviewed to identify those containing one or more <1.5-cm pancreatic cysts. For these patients, patient, lesion, and radiologist features and follow-up recommendations for FCPL were extracted. A nonlinear random-effects model estimated degree of variation in follow-up recommendations across radiologists at department and division levels.

RESULTS

Of 2,872 reports with FCPLs < 1.5 cm, 708 (24.7%) had FCPL-related follow-up recommendations. Average patient age was 67 years (SD ± 11). In all, 1,721 (60.0%) reports were for female patients; 59.3% of patients had only one cyst. In multivariable analysis, older patients had slightly lower follow-up recommendation rates (odds ratio [OR]: 0.98 [0.98-1.00] per additional year), and lesions associated with main duct dilatation and septation were more likely to have a follow-up recommendation (ORs: 1.93 [1.11-3.36] and 2.88 [1.89-4.38], respectively). Radiologist years in practice (P = .51), trainee presence (P = .21), and radiologist gender (P = .52) were not associated with increased follow-up recommendations. There was significant interradiologist variation in the Abdominal Imaging Division (P = .04), but not in Emergency Radiology (P = .31) or Cancer Imaging Divisions (P = .29).

DISCUSSION

Interradiologist variation significantly contributes to variability in follow-up imaging recommendations for FCPLs.

Integrity of clinical information in radiology reports documenting pulmonary nodules

OBJECTIVE

Quantify the integrity, measured as completeness and concordance with a thoracic radiologist, of documenting pulmonary nodule characteristics in CT reports and assess impact on making follow-up recommendations.

MATERIALS AND METHODS

This Institutional Review Board-approved, retrospective cohort study was performed at an academic medical center. Natural language processing was performed on radiology reports of CT scans of chest, abdomen, or spine completed in 2016 to assess presence of pulmonary nodules, excluding patients with lung cancer, of which 300 reports were randomly sampled to form the study cohort. Documentation of nodule characteristics were manually extracted from reports by 2 authors with 20% overlap. CT images corresponding to 60 randomly selected reports were further reviewed by a thoracic radiologist to record nodule characteristics. Documentation completeness for all characteristics were reported in percentage and compared using χ2 analysis. Concordance with a thoracic radiologist was reported as percentage agreement; impact on making follow-up recommendations was assessed using kappa.

RESULTS

Documentation completeness for pulmonary nodule characteristics differed across variables (range = 2%-90%, P < .001). Concordance with a thoracic radiologist was 75% for documenting nodule laterality and 29% for size. Follow-up recommendations were in agreement in 67% and 49% of reports when there was lack of completeness and concordance in documenting nodule size, respectively.

DISCUSSION

Essential pulmonary nodule characteristics were under-reported, potentially impacting recommendations for pulmonary nodule follow-up.

CONCLUSION

Lack of documentation of pulmonary nodule characteristics in radiology reports is common, with potential for compromising patient care and clinical decision support tools.

Integration of a Community Radiology Division into a Subspecialty-Focused Academic Radiology Department

INTRODUCTION

Assimilate a general radiology division into a subspecialty-focused radiology department at an academic medical center.

METHODS

This Institutional Review Board-approved quality improvement initiative was performed at an academic medical centers' subspecialty-focused academic radiology department, aiming to assimilate a general radiology division providing interpretive services for a distributed set of community ambulatory practices. An Oversight Committee charged by the department chair created a charter with unambiguous goal, timelines, clear decision-making, and conflict resolution processes. The Committee assessed the resources and clinical capabilities of the general radiologists, and the anticipated shift in exam volume from the community into subspecialty divisions. Primary outcome, percentage of targeted organ systems-specific interpretations by general radiologists based on assigned subspecialty division, and secondary outcome of report turnaround time (TAT) for all ambulatory exams, were compared before and after sub-specialization.

RESULTS

Among 10 general radiologists, 4.5 were assigned to subspecialty divisions; 5.5 continued to cover an independent general radiology practice in a for-profit delivery network. In the 5 months' post-transition, a total 86.6% (11,668/13,477) of reports by the integrated general radiologists were within designated subspecialty divisions vs 23.9% (2,586/10,829) pre-transition (P < 0.01). There was no change in ambulatory radiology report TAT for non-urgent care center (UCC) or UCC exams pre- vs post-integration.

DISCUSSION

A quality improvement initiative with unambiguous decision-making and conflict resolution processes incorporated a general radiology practice (radiologists and exams) into a subspecialty-focused academic radiology practice without negatively impacting TAT metrics. Future studies would be needed to assess impact on quality of interpretations.

Radiologist Variation in the Rates of Follow-up Imaging Recommendations Made for Pulmonary Nodules

OBJECTIVE

Determine whether differences exist in rates of follow-up recommendations made for pulmonary nodules after accounting for multiple patient and radiologist factors.

METHODS

This Institutional Review Board-approved, retrospective study was performed at an urban academic quaternary care hospital. We analyzed 142,001 chest and abdominal CT reports from January 1, 2016, to December 31, 2018, from abdominal, thoracic, and emergency radiology subspecialty divisions. A previously validated natural language processing (NLP) tool identified 24,512 reports documenting pulmonary nodule(s), excluding reports NLP-positive for lung cancer. A second validated NLP tool identified reports with follow-up recommendations specifically for pulmonary nodules. Multivariable logistic regression was used to determine the likelihood of pulmonary nodule follow-up recommendation. Interradiologist variability was quantified within subspecialty divisions.

RESULTS

NLP classified 4,939 of 24,512 (20.1%) reports as having a follow-up recommendation for pulmonary nodule. Male patients comprised 45.3% (11,097) of the patient cohort; average patient age was 61.4 years (±14.1 years). The majority of reports were from outpatient studies (62.7%, 15,376 of 24,512), were chest CTs (75.9%, 18,615 of 24,512), and were interpreted by thoracic radiologists (63.7%, 15,614 of 24,512). In multivariable analysis, studies for male patients (odds ratio [OR]: 0.9 [0.8-0.9]) and abdominal CTs (OR: 0.6 [0.6-0.7] compared with chest CT) were less likely to have a pulmonary nodule follow-up recommendation. Older patients had higher rates of follow-up recommendation (OR: 1.01 for each additional year). Division-level analysis showed up to 4.3-fold difference between radiologists in the probability of making a follow-up recommendation for a pulmonary nodule.

DISCUSSION

Significant differences exist in the probability of making a follow-up recommendation for pulmonary nodules among radiologists within the same subspecialty division.

Assessing information sources to elucidate diagnostic process errors in radiologic imaging - a human factors framework

Objective

To assess information sources that may elucidate errors related to radiologic diagnostic imaging, quantify the incidence of potential safety events from each source, and quantify the number of steps involved from diagnostic imaging chain and socio-technical factors.

Materials and Methods

This retrospective, Institutional Review Board-approved study was conducted at the ambulatory healthcare facilities associated with a large academic hospital. Five information sources were evaluated: an electronic safety reporting system (ESRS), alert notification for critical result (ANCR) system, picture archive and communication system (PACS)-based quality assurance (QA) tool, imaging peer-review system, and an imaging computerized physician order entry (CPOE) and scheduling system. Data from these sources (January-December 2015 for ESRS, ANCR, QA tool, and the peer-review system; January-October 2016 for the imaging ordering system) were collected to quantify the incidence of potential safety events. Reviewers classified events by the step(s) in the diagnostic process they could elucidate, and their socio-technical factors contributors per the Systems Engineering Initiative for Patient Safety (SEIPS) framework.

Results

Potential safety events ranged from 0.5% to 62.1% of events collected from each source. Each of the information sources contributed to elucidating diagnostic process errors in various steps of the diagnostic imaging chain and contributing socio-technical factors, primarily Person, Tasks, and Tools and Technology.

Discussion

Various information sources can differentially inform understanding diagnostic process errors related to radiologic diagnostic imaging.

Conclusion

Information sources elucidate errors in various steps within the diagnostic imaging workflow and can provide insight into socio-technical factors that impact patient safety in the diagnostic process.

A Bayesian decision support sequential model for severity of illness predictors and intensive care admissions in pneumonia

Background

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in the USA. Our objective was to assess the predictive value on critical illness and disposition of a sequential Bayesian Model that integrates Lactate and procalcitonin (PCT) for pneumonia.

Methods

Sensitivity and specificity of lactate and PCT attained from pooled meta-analysis data. Likelihood ratios calculated and inserted in Bayesian/ Fagan nomogram to calculate posttest probabilities. Bayesian Diagnostic Gains (BDG) were analyzed comparing pre and post-test probability. To assess the value of integrating both PCT and Lactate in Severity of Illness Prediction we built a model that combined CURB65 with PCT as the Pre-Test markers and later integrated the Lactate Likelihood Ratio Values to generate a combined CURB 65 + Procalcitonin + Lactate Sequential value.

Results

The BDG model integrated a CUBR65 Scores combined with Procalcitonin (LR+ and LR-) for Pre-Test Probability Intermediate and High with Lactate Positive Likelihood Ratios. This generated for the PCT LR+ Post-test Probability (POSITIVE TEST) Posterior probability: 93% (95% CI [91,96%]) and Post Test Probability (NEGATIVE TEST) of: 17% (95% CI [15–20%]) for the Intermediate subgroup and 97% for the high risk sub-group POSITIVE TEST: Post-Test probability:97% (95% CI [95,98%]) NEGATIVE TEST: Post-test probability: 33% (95% CI [31,36%]) . ANOVA analysis for CURB 65 (alone) vs CURB 65 and PCT (LR+) vs CURB 65 and PCT (LR+) and Lactate showed a statistically significant difference (P value = 0.013).

Conclusions

The sequential combination of CURB 65 plus PCT with Lactate yielded statistically significant results, demonstrating a greater predictive value for severity of illness thus ICU level care.

Factors Associated With Optimal Follow-up in Women With BI-RADS 3 Breast Findings

OBJECTIVE

Assess rate of and factors associated with optimal follow-up in patients with BI-RADS 3 breast findings.

METHODS

This Institutional Review Board-approved, retrospective cohort study, performed at an academic medical center, included all women undergoing breast imaging (ultrasound and mammography) in 2016. Index reports for unique patients with an assessment of BI-RADS 3 (retrieved via natural language processing) comprised the study population. Patient-specific and provider-related features were extracted from the Research Data Warehouse. The Institutional Cancer Registry identified patients diagnosed with breast cancer. Optimal follow-up rate was calculated as patients with follow-up imaging on the same breast 3 to 9 months from the index examination among patients with BI-RADS 3 assessments. Univariate analysis and multivariable logistic regression determined features associated with optimal follow-up. Malignancy rate and time to malignancy detection were recorded.

RESULTS

Among 93,685 breast imaging examinations, 64,771 were from unique patients of which 2,967 had BI-RADS 3 findings (4.6%). Excluding patients with off-site index examinations and those with another breast examination <3 months from the index, 1,125 of 1,511 patients (74%) had optimal follow-up. In univariate and multivariable analysis, prior breast cancer was associated with optimal follow-up; younger age, Hispanic ethnicity, divorced status, and lack of insurance were associated with not having optimal follow-up. Malignancy rate was 0.86%, and mean time to detection was 330 days.

DISCUSSION

Follow-up of BI-RADS 3 breast imaging findings is optimal in only 74% of women. Further interventions to promote follow-up should target younger, unmarried women, those with Hispanic ethnicity, and women without history of breast cancer and without insurance coverage.

Can Automated Retrieval of Data from Emergency Department Physician Notes Enhance the Imaging Order Entry Process?

BACKGROUND

When a paucity of clinical information is communicated from ordering physicians to radiologists at the time of radiology order entry, suboptimal imaging interpretations and patient care may result.

OBJECTIVES

Compare documentation of relevant clinical information in electronic health record (EHR) provider note to computed tomography (CT) order requisition, prior to ordering of head CT for emergency department (ED) patients presenting with headache.

METHODS

In this institutional review board-approved retrospective observational study performed between April 1, 2013 and September 30, 2014 at an adult quaternary academic hospital, we reviewed data from 666 consecutive ED encounters for patients with headaches who received head CT. The primary outcome was the number of concept unique identifiers (CUIs) relating to headache extracted via ontology-based natural language processing from the history of present illness (HPI) section in ED notes compared with the number of concepts obtained from the imaging order requisition.

RESULTS

Our analysis was conducted on cases where the HPI note section was completed prior to image order entry, which occurred in 23.1% (154/666) of encounters. For these 154 encounters, the number of CUIs specific to headache per note extracted from the HPI (median = 3, interquartile range [IQR]: 2-4) was significantly greater than the number of CUIs per encounter obtained from the imaging order requisition (median = 1, IQR: 1-2; Wilcoxon signed rank p < 0.0001). Extracted concepts from notes were distinct from order requisition indications in 92.9% (143/154) of cases.

CONCLUSION

EHR provider notes are a valuable source of relevant clinical information at the time of imaging test ordering. Automated extraction of clinical information from notes to prepopulate imaging order requisitions may improve communication between ordering physicians and radiologists, enhance efficiency of ordering process by reducing redundant data entry, and may help improve clinical relevance of clinical decision support at the time of order entry, potentially reducing provider burnout from extraneous alerts.

Classifying Safety Events Related to Diagnostic Imaging From a Safety Reporting System Using a Human Factors Framework

Purpose:

To measure diagnostic imaging safety events reported to an electronic safety reporting system (ESRS) and assess steps where they occurred within the diagnostic imaging workflow and contributing socio-technical factors.

Methods:

We evaluated all ESRS safety reports related to diagnostic imaging during calendar 2015 at an academic medical center with 50,000 admissions, 950,000 ambulatory visits, and performing 680,000 diagnostic imaging studies annually. Each report was assigned a 0-4 harm score by the reporter; we classified scores of 2 (minor harm) to 4 (death) as “potential harm”. Two reviewers manually classified reports into steps involved in the diagnostic imaging chain and socio-technical factors per the Systems Engineering Initiative for Patient Safety (SEIPS) framework. Kappa measured inter-reviewer agreement on 10% of reports. The percentage of reports that could cause “potential harm” was compared for each step and socio-technical factor using chi-square analysis.

Results:

Of 11,570 safety reports submitted in 2015, 854 (7%) were related to diagnostic imaging. Although the most common step was Imaging Procedure (54% of reports), potential harm occurred more in Report Communication (Odds Ratio=2.36, p=0.05). Person factors most commonly contributed to safety reports (71%). Potential harm occurred more in safety reports that were related to Task compared to Person factors (OR=5.03, p<0.0001). Kappa was 0.79.

Conclusion:

Safety events were related to diagnostic imaging in 7% of reports and potential harm occurred primarily during Imaging Procedure and Report Communication. Safety events were attributed to multifactorial socio-technical factors. Further work is necessary to decrease safety events related to diagnostic imaging.

HEART Score and Stress Test Emergency Department Bayesian Decision Scheme: Results from the Acute Care Diagnostic Collaboration

BACKGROUND

Accurate identification of patients at risk of major adverse cardiac events (MACE) places a substantial burden on emergency physicians (EPs). Bayesian nomogram for risk stratification in low- to intermediate-risk cardiovascular patients has not been investigated previously.

OBJECTIVE

The objective of this study was to develop a comparative diagnostic model using Bayesian statistics for exercise treadmill test (ETT) and stress echocardiogram (ECHO) to calculate post-test diagnostic risk of MACE using HEART (history, electrocardiogram, age, risk factors, and troponin) risk score as predictor of pretest probability.

METHODS

Stratification was made by applying HEART scores for the prediction of MACE. Likelihood ratios (LR) were calculated using pooled sensitivity and specificity of ETT and ECHO from the American College of Cardiology Foundation/American Heart Association systematic review. Post-test probabilities were obtained after inserting HEART score and LR into Bayesian nomogram. Analysis of variance was used to assess statistical association.

RESULTS

Positive LR (LR+) for ETT was 4.56 and negative LR (LR-) was 0.27; for ECHO, LR+ 5.65 and LR- 0.15. Bayesian statistical modeling post-test probabilities for LR+ and low HEART risk yielded a post-test probability for ETT of 7.75% and 9.09% for ECHO; intermediate risk gave 47.62% and 52.63%, respectively. For LR-, low HEART risk post-test probability for ETT was 0.46% and for ECHO 0.26%; intermediate risk probabilities were 4.48% and 2.49%, respectively. LR- was statistically significant in ruling out MACE with ECHO (p < 0.001), but no significant differences were seen for LR+ (p = 0.64).

CONCLUSIONS

This Bayesian analysis demonstrated slight superiority of stress ECHO over ETT in low- and intermediate-risk patients in ruling out MACE.

Bayesian comparative assessment of diagnostic accuracy of low-dose CT scan and ultrasonography in the diagnosis of urolithiasis after the application of the STONE score

OBJECTIVE

The objective of our study was to assess the diagnostic quality of low-dose computed tomography (CT) when compared to ultrasound (US) in diagnosis of urolithiasis using STONE score as a predictor of pre-test probability and the Bayesian statistical model to calculate post-test probabilities (POST) for both diagnostic tests.

METHODS

STONE score was used to form risk groups to obtain pre-test probabilities. Likelihood ratios (LR) were calculated from external data for low-dose CT and US. POST were obtained using pre-test probabilities and likelihood ratios with Bayesian nomogram. Absolute (ADG) and relative (RDG) gains in diagnostic value were calculated.

RESULTS

Calculated +LR for US was 12 and -LR was 0.32; for CT, +LR was 19 and -LR 0.04. +LR and low STONE for US yielded POST 57% and RDG 470%; intermediate STONE POST 92% and RDG 84%; and high STONE POST 99% and RDG 10%. -LR and low STONE for US POST 3% and RDG -70%; intermediate POST 24% and RDG -52%; and high STONE POST 74% and RDG -17.7%. +LR and low STONE for CT POST 68% and RDG 580%; moderate STONE POST 95% and RDG 90%; and high STONE POST 99% and RDG 10%. -LR and low STONE for CT POST 0% and RDG -100%; intermediate POST 4% and RDG -92%; and high STONE POST 26% and RDG -71.1%. ANOVA calculations comparing CT vs US for +LR showed no statistical significance (P value = 0.9893; LR- P value = 0.5488).

CONCLUSION

Bayesian statistical analysis demonstrated slight superiority of CT scan over US on STONE score low- and moderate-risk stratified subtypes, whereas no significant advantage was seen when evaluating high-probability patients.

Bayesian comparative model of CT scan and ultrasonography in the assessment of acute appendicitis: results from the Acute Care Diagnostic Collaboration project

The objective of this study was to develop a comparative diagnostic model for computed tomography (CT) and ultrasound (US) in the assessment of acute appendicitis using Alvarado risk score as a predictor of pretest probability and Bayesian statistical model as a tool to calculate posttest probabilities for both diagnostic test. Stratification was made by applying the Alvarado score for the prediction of acute appendicitis. Likelihood ratios were calculated using sensitivity and specificity of both CT and US from a Meta-analysis. Posttest probabilities were obtained after inserting Alvarado score and likelihood ratios into Bayesian nomogram. Absolute and relative gains were calculated. ANOVA was used to assess statistical association. 4341 patients from 31 studies yielded a pooled sensitivity and specificity US of 83% (95% CI, 78%-87%) and 93% (95% CI, 90%-96%) and 94% (95% CI, 92%-95%) and 94% (95% CI, 94%-96%), respectively, for CT studies. Positive likelihood ratios (LR) for US were 12 and negative LR was 0.18; for CT +LR was 16 and -LR 0.06. Bayesian statistical modeling posttest probabilities for +LR and low Alvarado risk results yielded a posttest probability for US of 83.72% and 87.27% for CT, intermediate risk gave 95.88% and 96.88%, high risk 99.37% and 99.53 respectively. No statistical differences were found between Ultrasound and CT. This Bayesian analysis demonstrated slight superiority of CT scan over US low-risk patients, whereas no significant advantage was seen when evaluating intermediate and high risk patients. This study also favored elevated accuracy of the Alvarado score.

A prospective, randomized, pharmacodynamic study of quick-starting a desogestrel progestin-only pill following ulipristal acetate for emergency contraception

STUDY QUESTION

Is there a pharmacodynamic interaction between ulipristal acetate (UPA) 30 mg for emergency contraception and a daily progestin-only contraceptive pill, desogestrel (DSG) 0.75 mg, when initiated the next day?

SUMMARY ANSWER

In this study, DSG impaired the ability of UPA to delay ovulation, but UPA had little impact on the onset of contraceptive effects due to DSG.

WHAT IS KNOWN ALREADY

UPA is a progesterone receptor modulator used for emergency contraceptive (EC) at the dose of 30 mg. UPA delays ovulation by at least 5 days when administered in the mid to late follicular phase. In theory, potent progestins could reactivate progesterone signaling that leads to follicle rupture, thereby impacting the effectiveness of UPA as EC. In addition, UPA could alter the onset of the contraceptive effect of progestin-containing contraceptives started immediately after UPA.

STUDY DESIGN, SIZE, DURATION

A single-blind (for observer), placebo-controlled, partial crossover study was conducted in two sites [Dominican Republic (DR) and the Netherlands (NDL)] over 11 months from October 2012 to September 2013. Healthy female volunteers participated in two of the three treatment cycles separated by a washout cycle. Treatment combinations studied were as follows: (i) a single 30 mg dose of UPA followed by 75 µg per day DSG for 20 days, (ii) a single 30 mg dose of UPA followed by 20 days of placebo matching that of DSG (PLB2) or (iii) one tablet of placebo-matching UPA (PLB1) followed by 75 µg per day DSG for 20 days. Participants were randomized to one of the three treatment sequences (UPA + DSG/UPA + PLB2, PLB1 + DSG/UPA + DSG and UPA + PLB2/PLB1 + DSG) when a lead follicle was ≥ 14 to <16 mm diameter on transvaginal ultrasound imaging (TVU).

PARTICIPANTS/MATERIAL, SETTING, METHODS

A total of 71 women were included, and 49 were randomized to a first treatment combination of the three period sequences (20 in the DR and 29 in the NDL); 41 of the 49 continued and completed two treatment combinations (20 in the DR and 21 in the NDL).

MAIN RESULTS AND THE ROLE OF CHANCE

Initiating DSG treatment the day after UPA significantly reduced the ovulation delaying effect of UPA (P = 0.0054). While ovulation occurred in only one of the 29 UPA-only cycles (3%) in the first 5 days, it occurred in 13 of the 29 (45%) UPA + DSG cycles.

LIMITATIONS, REASONS FOR CAUTION

This was a small, descriptive, pharmacodynamic study in which some findings differed by study site. Distinguishing between a cystic corpus luteum and a luteinized unruptured follicle (LUF) by TVU was difficult in some cases; however, the investigators reached consensus, when the study was still blinded, regarding ovulation based on hormone levels and careful review of daily TVU images.

WIDER IMPLICATIONS OF THE FINDINGS

Initiating the use of a DSG progestin-only pill (POP) immediately after UPA reduces the ability of UPA to delay ovulation and thus may decrease its efficacy as EC. If starting a DSG POP after using UPA for EC, and possibly any progestin-only method, consideration should be given to delaying for at least 5 days after UPA intake in order to preserve the ovulation delaying effects of UPA.

Changes in rat soleus muscle phenotype consecutive to a growth in hypergravity followed by normogravity

It has been demonstrated that a long-term stay in hypergravity (HG: 2G) modified the phenotype and the contractile properties of rat soleus muscle. The ability of this muscle to contract was drastically reduced, which is a sign of anticipated aging. Consequently, our aim was to determine whether rats conceived, born, and reared in hypergravity showed adaptative capacities in normogravity (NG: 1G). This study was performed on rats divided into two series: the first was reared in HG until 100 days and was submitted to normogravity until 115 to 220 postnatal days (HG-NG rats); the second was made up of age paired groups reared in normogravity (NG rats). The contractile, morphological, and phenotypical properties of soleus muscle were studied. Our results showed that the NG rats were characterized by coexpressions of slow and fast myosin, respectively, 76.5 and 23.5% at 115 days. During their postnatal maturation, the fast isoform was gradually replaced by slow myosin. At 220 days, the relative proportions were respectively 91.05% and 8.95%. From 115 to 220 days, the HG-NG rats expressed 100% of slow myosin isoform and they presented a slower contractile behavior compared with their age-matched groups; at 115 days, the whole muscle contraction time was increased by 35%, and by 15%, at 220 days. Our study underlined the importance of gravity in the muscular development and suggested the existence of critical periods in muscle phenotype installation.

Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation

We assessed to what extent the standard dose of levonorgestrel (LNG), used for emergency contraception, or a single dose (half dose), given in the follicular phase, affects the ovulatory process during the ensuing 5-day period. Fifty-eight women were divided into three groups according to timing of treatment. Each woman contributed with three treatment cycles separated by resting cycles. All received placebo in one cycle, and standard or single dose in two other cycles, in a randomized order. The diameter of the dominant follicle determined the time of treatment. Each woman had the same diameter assigned for all her treatments. Diameters were grouped into 33 categories: 12-14, 15-17 or 18-20 mm. Follicular rupture failed to occur during the 5-day period in 44%, 50% and 36% of cycles with the standard, half dose and placebo, respectively. Ovulatory dysfunction, characterized by follicular rupture associated with absent, blunted or mistimed gonadotropin surge, occurred in 35%, 36% and 5% of standard, single dose or placebo cycles, respectively. In conclusion, LNG can disrupt the ovulatory process in 93% of cycles treated when the diameter of the dominant follicle is between 12 and 17 mm. It is highly probable that this mode of action fully accounts for the contraceptive efficacy as well as the failure rate of this method. The present data suggest that half the dose may be as effective as the standard dose.

Effects of the Yuzpe regimen, given during the follicular phase, on ovarian function

This study was conducted to assess to what extent the Yuzpe regimen, or half the dose, given in the follicular phase, prevents ovulation during the ensuing 5 days. Sixty women were divided into six groups. All groups received placebo in one cycle and drug in another, in a randomized order. Groups differed by the dose and size of the leading follicle at the time of treatment (12-14, 15-17, or 18-20 mm). Ovulation was absent during the ensuing 5 days in 13 of 20 participants (65%) and in 8 of 20 participants (40%) who received the full and the half dose, respectively, when follicles were 12-17 mm. No ovulation occurred, within the critical period, in 7 of 39 placebo cycles (18%). When follicles were 18-20 mm, treatment did not prevent ovulation. In most drug-treated cycles, plasma gonadotropin and sex steroid levels were significantly depressed within the 5-day period, even when follicular rupture occurred within that period. In conclusion, the Yuzpe regimen can suppress or postpone ovulation to an extent that exceeds the fertile life of spermatozoa. Lack of ovulation within the critical period and dysfunction of the ovulatory process probably account for the contraceptive effect of this method in most cases. The present data do not warrant the use of half the dose of the Yuzpe regimen.

Nonmenstrual adverse events during use of implantable contraceptives for women: data from clinical trials

Contraceptive methods, including implants, do not prevent common symptoms and adverse health events that most people experience. It is difficult, therefore, to decide whether or not the occurrence of symptoms or adverse events that are common can be attributed to use of a contraceptive method or to determine if a given method changes the likelihood of their occurrence. Based on the review of the literature, no apparent differences in the frequency of adverse events are evident between the six-implant or two-rod levonorgestrel systems and the single implant etonogestrel and nomegestrol acetate systems. The most frequent adverse events reported in clinical trials that are probably related to implant use are headaches and acne. Weight gain, dizziness, and mood changes are also frequently mentioned adverse events and are possibly steroid-related. Other possibly related adverse events, although much less frequently reported, are loss of libido, fatigue, hair loss, and other skin conditions. Persistent ovarian follicles that spontaneously disappear are a common event during use of progestin-only contraceptives, and providers should be aware of this condition to avoid unnecessary interventions. Overall, the vast experience reported in the clinical studies reviewed here show that all existing implantable contraceptives are equally safe. This can probably be attributed to the low-hormonal dose delivered by progestin-implant systems.

Ovarian function during use of Nestorone(R) subdermal implants

Nestorone(R) progestin (NES) is a potent 19-nor-progesterone derivative which is biologically inactive when administered orally; however, it is an excellent option for implant contraception. The objective of this study was to evaluate ovarian function during use of either one 4-cm or two 3-cm NES implants for 24 months. A total of 60 volunteers were enrolled in each dose group. Vaginal ultrasound (VUS) and blood sampling for determinations of estradiol (E(2)), progesterone (P) and NES serum levels were carried out twice a week for 6 consecutive weeks, beginning in months 1, 6, 12, 18, and 24 of implant use. Serum levels of NES declined with time, with a more pronounced decrease during the first 18 months of implant use; thereafter, NES levels remained stable until the end of the study at 24 months. Luteal activity was very infrequent during the first year of use (<3%) but increased during the second year, occurring in 27% and 35% of the sampling periods in the 1-implant group, and 2% and 16% of the sampling periods in the 2-implant group, at months 18 and 24 of use, respectively. No luteal activity was observed with NES levels above 80 pmol/L. Serum P levels in periods of luteal activity were significantly lower than those of controls. Persistent anovulatory follicles were the most common VUS finding and this was associated with E(2) levels that remained within the normal range (101-1500 pmol/L) in the majority of the sampling periods studied. Considering that a single implant offers advantage for insertion and removal, a new single NES implant is being developed with a slightly higher release rate, to reduce effectively the incidence of ovulation and provide a greater margin of safety beyond 2 years.

Prevalence of enlarged ovarian follicles among users of levonorgestrel subdermal contraceptive implants (Norplant)

OBJECTIVE

The aim of this study was to determine the prevalence of enlarged follicles, as detected by a single clinical or ultrasonographic examination, among users of levonorgestrel subdermal contraceptive implants (Norplant implants).

STUDY DESIGN

This was a cross-sectional study of 103 users of Norplant implants and 50 users of the TCu380A intrauterine contraceptive device, all of whom received reproductive health services from PROFAMILIA, Santo Domingo, Dominican Republic. Bimanual pelvic examination and vaginal ultrasonography were performed. Enlarged follicles (>25 mm) were followed up weekly. The chi(2) test was applied to these data.

RESULTS

Enlarged follicles were detected by ultrasonography in 17. 5% of Norplant implants users and 4% of TCu380A intrauterine contraceptive device users, respectively (P <.04). There was no difference according to duration of use. The longest time to involution of the follicles was 4 weeks. Forty percent of the enlarged follicles detected by ultrasonography were also detected by bimanual pelvic examination.

CONCLUSION

Enlarged follicles are a frequent finding among women who use Norplant implants, but they are less frequent than described in previous studies, which were based on serial ultrasonographic scans in selected groups of users. Physicians and users should be aware of the transient nature of these enlarged follicles, which do not require intervention.

Timing of onset of contraceptive effectiveness in Norplant implant users. II. Effect on the ovarian function in the first cycle of use

The objective of this study was to time the onset of contraceptive effectiveness in Norplant implant users, when the capsules were inserted beyond the first 7 days of the cycle, based on the immediate effect on the ovarian activity. A total of 42 healthy women requesting Norplant implant contraception were enrolled at clinics in Santo Domingo, Dominican Republic, and in Baltimore, Maryland. Implants were inserted on days 8-13 of the menstrual cycle. Blood samples for estradiol (E2), progesterone (P), luteinizing hormone (LH) (in a subset of 12 women), and levonogestrel (LNG) assay, were taken at 0 h and at 6, 12, 24, 72, and 168 h postinsertion. Ovulation, as defined by P > 2.5 ng/mL, occurred in 40% of subjects. A short lasting, frequently blunted, LH peak occurred within 12 h postinsertion, in all these subjects. The remaining subjects had anovulatory cycles with two distinct E2 profiles: continuously increasing E2 levels to a high mean of 414.3 pg/mL (28%), or no sustained increase in E2 (32%). Most cycles (86%) in which Norplant was inserted with high E2 levels (> 175 pg/mL) were ovulatory, whereas none were ovulatory with low E2 (< 100 pg/mL) at insertion. Based on the endocrine effects of Norplant implant insertion in the midadvanced follicular phase, in which ovulation will either occur within 48 h of insertion or will be impaired, additional contraceptive protection is necessary only for 3 days.

Sex hormone binding globulin and free levonorgestrel index in the first week after insertion of Norplant implants

Levonorgestrel has an inhibitory effect on sex hormone binding globulin (SHBG). This decrease in SHBG leads to an increase in the free levonorgestrel index (FLI), which has a stronger biological effect. The interaction between serum levels of levonorgestrel and SHBG in long-term users of Norplant implants has been described. This study was designed to understand the same interaction immediately after the insertion of the implants, in a group of 16 women, sampled at 0 and 6 h and at 1, 3, and 7 days after Norplant implant insertion. Peak serum levonorgestrel levels were achieved at 24 h after insertion, remaining stable on day 3 and decreasing by > 10% by day 7. SHBG did not change during the first 24 h, but decreased by 19% and 60% on days 3 and 7, respectively. FLI more than doubled from day 1 to day 7 after insertion. The large decrease in SHBG and doubling of FLI is not followed by a similar reduction in levonorgestrel, which is hard to explain without an increase in the release rate of the steroid from the capsule.

Timing of onset of contraceptive effectiveness in Norplant implant users. Part I. Changes in cervical mucus

OBJECTIVE

To provide scientific data regarding the changes in cervical mucus within the first hours to days after Norplant implant insertion and to estimate when the cervical mucus is hostile enough to suggest a contraceptive effect.

DESIGN

Multicenter, clinical descriptive study.

SETTING

Family planning clinics.

PATIENT(S)

Forty-two women who were between days 8 and 13 of their menstrual cycle and who had requested Norplant implants were admitted to the study.

INTERVENTION(S)

Cervical mucus and blood samples were obtained.

MAIN OUTCOME MEASURE(S)

Cervical mucus scores, sperm penetration distances, and serum levels of progesterone, estradiol, and levonorgestrel.

RESULT(S)

The median cervical mucus score observed at baseline was 6 ("fair"), indicating that the mucus was already somewhat hostile before insertion of the Norplant implants. The median scores declined to 5 at 12 and 24 hours and continued to decrease through day 7 to 2 ("poor"), a score that is judged as hostile to sperm penetration. Overall, 73% of all subjects had a poor cervical mucus score by 3 days after insertion; at 7 days after insertion, 90% exhibited poor mucus and none had a good score. There was a substantial drop in the overall median distance traveled by the vanguard sperm after 12 hours for each cervical mucus score grouping. The distance traveled decreased rapidly between 12 and 24 hours to < 0.5 cm in subjects with fair and poor mucus, and by day 3, 91% of the subjects exhibited poor sperm penetration.

CONCLUSION(S)

On the basis of our findings, deterioration of the quality of the cervical mucus and sperm penetration is evident by 24 hours after insertion, although not to a level that would suggest adequate protection until 72 hours after insertion. Therefore, we are confident in recommending that backup methods of contraception (e.g, condoms) need not be used for more than 3 days after insertion, even when the implants are inserted close to ovulation. These findings provide policy makers, clinic managers, and clinicians with important information about how they can improve client access to Norplant implants.

Effect of preovulatory insertion of Norplant implants over luteinizing hormone secretion and follicular development

OBJECTIVE

To determine whether the process of ovulation could be interrupted by the insertion of Norplant implants (Leiras Pharmaceuticals, Turku, Finland) in the advanced preovulatory phase.

DESIGN

Prospective study.

SETTING

The Department of Biomedical Research at the Family Planning Clinic of PROFAMILIA, Santo Domingo, Dominican Republic.

PATIENTS

Healthy women of reproductive age, requesting Norplant implants contraception. Thirteen of 15 women volunteers who were admitted completed the study.

INTERVENTIONS

Norplant implants were inserted when the dominant follicle reached a mean diameter of 16 mm, based on serial vaginal ultrasounds (US) beginning on day 10 of the cycle. Blood samples for determination of E2, P, LH, and levonorgestrel, were taken and vaginal US performed at 0, 4, 24, 48, and 72 hours after insertion. If follicle rupture had not occurred at 72 hours after insertion, blood sampling and US were done three times per week during 2 additional weeks.

RESULTS

Follicle rupture occurred in 11 of 13 subjects within 72 hours after insertion, with the exception of 1 subject in whom rupture occurred between 72 and 192 hours. Two women already had an LH peak at the time of insertion. In 9 of the remaining 11 women, a shortlasting, blunted LH surge was observed at 4 hours postinsertion. In the remaining two women, who had the lowest E2 levels, ovulation was inhibited, and a persistent follicle developed without luteinization.

CONCLUSIONS

The insertion of Norplant implants in the advanced follicular phase will not inhibit ovulation if sufficient E2 priming has occurred. On the contrary, the exogenous progestin may rapidly foster ovulation shortly after.

Hormonal treatment for bleeding irregularities in Norplant implant users

OBJECTIVE

Our purpose was to evaluate whether prolonged or irregular bleeding during Norplant implant use could be alleviated with the use of oral hormonal medication.

STUDY DESIGN

One hundred fifty users of the Norplant levonorgestrel contraceptive implant with prolonged or frequent bleeding were enrolled in this prospective, randomized, comparative study and assigned to one of three treatment groups for 20 days: ethinyl estradiol 50 microg, an oral contraceptive (50 microg ethinyl estradiol and 250 microg levonogestrel), and placebo. Total days of bleeding during treatment and length of the bleeding-free interval were analyzed.

RESULTS

Women treated with the levonorgestrel-ethinyl estradiol pill bled an average of 2.6 days during treatment compared with 5.4 and 12.3 days in the ethinyl estradiol and placebo groups, respectively. Differences between both hormonal groups and placebo were significant (p <0.00001); moreover, the combined pill was more effective than ethinyl estradiol along (p <0.0001).

CONCLUSION

The combined pill proved to be an excellent palliative treatment and is a more practical approach because of availability at all clinic sites.

Free levonorgestrel index and its relationship with luteal activity during long-term use of Norplant implants

Levonorgestrel serum levels and sex hormone binding globulin (SHBG) were measured in 82 women during different years of use of Norplant implants. The ratio between levonorgestrel and SHBG was calculated as an indicator of the free biologically active fraction of levonorgestrel (free levonorgestrel index, FLI). These parameters were then correlated with the presence of luteal activity, as determined by progesterone levels above 9.6 nmol/L, in a sampling run of 10 samples taken twice a week for five consecutive weeks. Levonorgestrel serum levels remained constant around 1.0 nmol/L during the five-year period. SHBG levels were below normal for the first 18 months of use, returning to normal levels during the last three years of use. The FLI in the first two years was significantly higher than that observed in the later years. The frequency of cycles with luteal activity was 12% during the first 2 years, increasing to 44% in the latter years, when FLI levels were lower. Our results suggest that the changes in SHBG and consequently in the free biologically active fraction of levonorgestrel may largely account for the differences in degree of ovarian suppression observed between the first two years of use of Norplant implants and the latter three, even in the absence of a significant variation in total levonorgestrel concentrations.

Ovulatory dysfunction during continuous administration of low-dose levonorgestrel by subdermal implants

OBJECTIVE

To study the endocrinologic profile of regularly menstruating users of levonorgestrel subdermal implants.

DESIGN

Observational, prospective, case-controlled comparative study.

SETTING

The Family Planning Clinic of PROFAMILIA, in Santo Domingo, Dominican Republic.

PATIENTS, PARTICIPANTS

Thirty one regularly cycling Norplant users and 12 nonhormonal contraceptors who volunteered to participate.

INTERVENTIONS

Norplant contraceptive implants were inserted in 31 subjects between 13 and 77 months before this study.

MAIN OUTCOME MEASURES

Follicle-stimulating hormone, luteinizing hormone, estradiol (E2), and progesterone (P) were serially assayed for one menstrual cycle.

RESULTS

Almost half of the cycles among Norplant users were anovulatory; all the rest (55%) had some form of dysfunction: diminished gonadotropin surge, luteal phase insufficiency (low P levels and shortened luteal phase), and E2 profiles different from normal controls.

CONCLUSIONS

Anovulation is clearly one of the main mechanisms of action of Norplant, but even in presumptive ovulatory cycles, the dysfunctions described possibly contribute to the high contraceptive effectiveness of Norplant.

Ovarian endocrine function through five years of continuous treatment with NORPLANT subdermal contraceptive implants

Ovarian endocrine function was assessed in 88 women using NORPLANT subdermal implants during different periods of use and in a control group of 15 women using non-hormonal contraception. Blood samples for estradiol (E2) and progesterone (P) assays were obtained twice a week for five consecutive weeks. Three distinct E2 patterns were observed: one was characterized by fluctuating levels within a normal range (20 to 400 pg/ml), a second pattern corresponded to continuous low E2 levels (below 75 pg/ml in the 10 samples) and the third was characterized by high broad estradiol peaks reaching over 400 pg/ml. The proportion of sampling runs characterized by normal fluctuating levels increased from 38% in the first two years of use to 80% during the fifth year of use. Low E2 profile was only observed during the first two years of use (27%) and in only 1 case at the beginning of the third year of use (5%). The percentage of cycles with high broad estradiol peaks remained between 20-40% without a clear tendency to change in either direction with duration of use. Thirty-three percent of the observed sampling runs had luteal activity (P above 3 ng/ml). The proportion of runs with luteal activity increased from 14% during the first two years of use to 40% during the third and fourth, and 60% during the fifth year of use. All control subjects had luteal activity. The mean highest progesterone level was lower in the NORPLANT runs (8.7 +/- 3.9 ng/ml) as compared to the controls (11.3 +/- 3.8 ng/ml). NORPLANT sampling runs with luteal activity had normal fluctuating E2 levels with only one exception. However, not all cycles with normal E2 levels showed luteal activity. On the other hand, all runs with low E2 levels or high broad E2 peaks were without luteal activity. In summary, women using continuous low-dose levonorgestrel contraception through NORPLANT subdermal implants, have a variable degree of ovarian activity as compared with the more complete depression of ovarian function observed among pill or injectables' users. Ovarian activity becomes closer to normal during the third through fifth year of use.