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Increasing complexity of mAbs in development creates challenges in predicting human pharmacokinetic (PK) parameters from preclinical data. The aim of this analysis was to identify optimal allometric scaling exponents.Data were extracted from literature to create a central database (currently the largest available published database) of two-compartment model parameters for mAbs (n = 59) in cynomolgus monkey (CM) and human.Global allometric exponents were calculated and drug-dependent factors were investigated as potential variables in determining the optimal scaling factor.The global exponents for scaling CM mAb PK data were 0.74 (CL), 0.80 (CL with Fc-modified mAbs excluded), 0.44 (CL with Fc-modified mAbs only), 0.71 (Q), 1.12 (V1), and 0.99 (V2). These values are in line with previously published literature values.
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Medical professionals are increasingly required to use digital technologies as part of care delivery and this may represent a risk for medical error and subsequent malpractice liability. For example, if there is a medical error, should the error be attributed to the clinician or the artificial intelligence-based clinical decision-making system? In this article, we identify and discuss digital health technology-specific risks for malpractice liability and offer practical advice for the mitigation of malpractice risk.
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Background: Time to pregnancy (TTP) is a biomarker of fecundability and has been associated with behavioral and environmental characteristics; however, these associations have not been examined in a large population-based sample of application (app) users. Materials and Methods: This observational study followed 5,376 women with an age range of 18 to 45 years who used an app to identify their fertile window. We included women who started trying to conceive between September 30, 2017 and August 31, 2018. TTP was calculated as the number of menstrual cycles from when the user switched to "Plan" mode up to and including the cycle in which they logged a positive pregnancy test. We examined associations with several characteristics, including age, gravidity, body mass index, cycle length and cycle length variation, frequency of sexual intercourse, and temperature measuring frequency. Discrete time fecundability models were used to estimate fecundability odds ratios. Results: For the complete cohort the 6-cycle and 12-cycle cumulative pregnancy probabilities were found to be 61% (95% confidence interval [CI]: 59-62) and 74% (95% CI: 73-76), respectively. The median TTP was four cycles. The highest fecundability was associated with an age of less than 35 years, with cycle length variation <5 days and logging sexual intercourse on at least 20% of days added (the proportion of days in which intercourse was logged) (11.5% [n = 613] of entire sample). This group achieved a 6- and 12-cycle cumulative pregnancy probability of 88% (95% CI: 85-91) and 95% (95% CI: 94-97), respectively, and a TTP of 2 cycles. Conclusions: Natural Cycles was an effective method of identifying the fertile window and a noninvasive educational option for women planning a pregnancy. Women under age 35 with regular cycles showed a high pregnancy rate.
Subject(s)
Mobile Applications , Adolescent , Adult , Cohort Studies , Female , Fertility , Humans , Middle Aged , Pregnancy , Pregnancy Rate , Prospective Studies , Time-to-Pregnancy , Young AdultABSTRACT
PURPOSE: Digital fertility awareness-based contraception offers an alternative choice for women who do not wish to use hormonal or invasive methods. The aim of this study was to investigate the key demographics of current users of the Natural Cycles app and assess the contraceptive outcomes of women preventing pregnancy in a UK cohort of women. MATERIALS AND METHODS: This was a real world observational prospective observational study. The typical-use effectiveness of the method was calculated using both 13-cycle cumulative probability of pregnancy (life table analysis) and Pearl Index for the entire study cohort. Perfect-use PI was calculated using data from cycles where sexual intercourse during the fertile window was marked as protected and no unprotected sex was recorded on fertile days. RESULTS: 12,247 women were included in the study and contributed an average of 9.9 months of data for a total of 10,066 woman years of exposure. The mean age of the cohort was 30, mean BMI 23.4, the majority were in a stable relationship (83.2%) and had a university degree or higher (83%). The one year typical use, PI was 6.1 (95% CI: 5.6, 6.6) and with perfect-use was 2.0 (95% CI: 1.3, 2.8). 13 cycle pregnancy probability was 7.1%. CONCLUSIONS: This is the first study which describes the use of a digital contraceptive by women in the UK. It describes the demographics of users and how they correlate with the apps effectiveness at preventing pregnancy.
Subject(s)
Contraception , Contraceptive Agents , Fertility , Mobile Applications , Adult , Female , Humans , Life Tables , Middle Aged , Pregnancy , Prospective Studies , United KingdomABSTRACT
Background: Digital fertility awareness-based methods of birth control are an attractive alternative to hormonal or invasive birth control for modern women. They are also popular among women who may be planning a pregnancy over the coming years and wish to learn about their individual menstrual cycle. The aim of this study was to assess the effectiveness of the Natural Cycles app at preventing pregnancy for a cohort of women from the United States and to describe the key demographics of current users of the app in such a cohort. Materials and Methods: This prospective real-world cohort study included users who purchased an annual subscription to prevent pregnancy. Demographics were assessed through answers to in-app questionnaires. Birth control effectiveness estimates for the entire cohort were calculated using 1-year pearl index (PI) and 13-cycle cumulative pregnancy probability (Kaplan-Meier life table analysis). Results: The study included 5879 women who contributed an average of 10.5 months of data for a total of 5125 woman-years of exposure. The average user was 30 years old with a body mass index of 24 and reported being in a stable relationship. With typical use, the app had a 13-cycle cumulative pregnancy probability of 7.2% and a 1-year typical use PI of 6.2. When the app was used under perfect use, the PI was 2.0. Conclusions: The data presented in this study give insights into the cohort of women using this app in the United States, and provide country-specific effectiveness estimates. The contraceptive effectiveness of the app was in line with previously published figures from Natural Cycles (PI of seven for typical use and two for perfect use).
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Contraceptive Effectiveness , Mobile Applications , Adult , Cohort Studies , Contraception , Female , Humans , Pregnancy , Prospective Studies , United StatesSubject(s)
Coronavirus Infections/blood , Coronavirus Infections/therapy , Mass Screening , Pneumonia, Viral/blood , Pneumonia, Viral/therapy , Testosterone/deficiency , COVID-19 , Coronavirus Infections/mortality , Early Diagnosis , Humans , Male , Pandemics , Pneumonia, Viral/mortality , Risk AssessmentABSTRACT
Despite growing interest from both patients and healthcare providers, there is little clinical guidance on how mobile apps should be utilized to add value to patient care. We categorize apps according to their functionality (e.g. preventative behavior change, digital self-management of a specific condition, diagnostic) and discuss evidence for effectiveness from published systematic reviews and meta-analyses and the relevance to patient care. We discuss the limitations of the current literature describing clinical outcomes from mHealth apps, what FDA clearance means now (510(k)/de novo FDA clearance) and in the future. We discuss data security and privacy as a major concern for patients when using mHealth apps. Patients are often not involved in the development of mobile health guidelines, and professionals' views regarding high-quality health apps may not reflect patients' views. We discuss efforts to develop guidelines for the development of safe and effective mHealth apps in the US and elsewhere and the role of independent app reviews sites in identifying mHealth apps for patient care. There are only a small number of clinical scenarios where published evidence suggests that mHealth apps may improve patient outcomes.
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Purpose: This study aims to compare the accuracy of fertile window identification with the contraceptive app Natural Cycles against the Rhythm Method and Standard Days Method (SDM).Materials and methods: Menstruation dates, basal body temperature (BBT), and luteinising hormone (LH) test results were collected anonymously from Natural Cycles app users. The fraction of green days (GDs) and wrong green days (WGDs) allocated by the various algorithms was determined over 12 cycles. For comparison of Natural Cycles and the Rhythm Method, 26,626 cycles were analysed.Results: Natural Cycles' algorithms allocated 59% GDs (LH, BBT) in cycle 12, while the fraction of WGDs averaged 0.08%. The Rhythm Method requires monitoring of six cycles, resulting in no GDs or WGDs in cycle 1-6. In cycle 7, 49% GDs and 0.26% WGDs were allocated. GDs and WGDs decreased to 43% and 0.08% in cycle 12. The probabilities of WGDs on the day before ovulation with Natural Cycles were 0.31% (BBT) and 0% (LH, BBT), and 0.80% with the Rhythm Method. The probability of WGDs on the day before ovulation was 6.90% with the SDM.Conclusions: This study highlights that individualised algorithms are advantageous for accurate determination of the fertile window and that static algorithms are more likely to fail during the most fertile days.
Subject(s)
Mobile Applications , Natural Family Planning Methods/methods , Ovulation Detection/methods , Adolescent , Adult , Algorithms , Body Temperature , Female , Humans , Luteinizing Hormone/urine , Middle Aged , Young AdultABSTRACT
The use of apps that record detailed menstrual cycle data presents a new opportunity to study the menstrual cycle. The aim of this study is to describe menstrual cycle characteristics observed from a large database of cycles collected through an app and investigate associations of menstrual cycle characteristics with cycle length, age and body mass index (BMI). Menstrual cycle parameters, including menstruation, basal body temperature (BBT) and luteinising hormone (LH) tests as well as age and BMI were collected anonymously from real-world users of the Natural Cycles app. We analysed 612,613 ovulatory cycles with a mean length of 29.3 days from 124,648 users. The mean follicular phase length was 16.9 days (95% CI: 10-30) and mean luteal phase length was 12.4 days (95% CI: 7-17). Mean cycle length decreased by 0.18 days (95% CI: 0.17-0.18, R 2 = 0.99) and mean follicular phase length decreased by 0.19 days (95% CI: 0.19-0.20, R 2 = 0.99) per year of age from 25 to 45 years. Mean variation of cycle length per woman was 0.4 days or 14% higher in women with a BMI of over 35 relative to women with a BMI of 18.5-25. This analysis details variations in menstrual cycle characteristics that are not widely known yet have significant implications for health and well-being. Clinically, women who wish to plan a pregnancy need to have intercourse on their fertile days. In order to identify the fertile period it is important to track physiological parameters such as basal body temperature and not just cycle length.
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Objective: The aim of the study was to compare the effect of previously used contraceptive methods on women's short- and long-term fecundity. Use of hormonal contraception (HC) was compared with the use of a contraceptive mobile application (app). Methods: This real-life prospective observational study comprised 2874 women who were attempting to become pregnant using the Natural Cycles mobile app to monitor their fertility. The women registered to use the app between August 2014 and June 2016 with the intention of planning a pregnancy and had previously either used the same app to prevent pregnancy or had recently discontinued HC use. We calculated the average time to pregnancy (TTP) for all women who became pregnant during the study and performed Kaplan-Meier life-table analysis to examine the cumulative probabilities of pregnancy for all women in the study. Results: The average TTP was 2.3 (95% confidence interval [CI] 2.1, 2.4) and 3.7 (95% CI 3.4, 3.9) cycles for women who had previously used Natural Cycles and HC, respectively. The time to reach 30% pregnancy probability for women previously on HC was 1.6 (95% CI 1.5, 1.8) times longer than for women previously using Natural Cycles. There was no significant difference in the 13 cycle cumulated pregnancy probability between the two groups. Conclusion: The results show that fertility awareness-based methods of contraception increase short-term pregnancy rates relative to HC, but have no effect on long-term pregnancy rates.
Subject(s)
Contraception/methods , Contraceptive Agents, Hormonal/adverse effects , Fertility/drug effects , Mobile Applications , Pregnancy Rate , Adult , Female , Fertilization , Humans , Life Tables , Pregnancy , Prospective Studies , Sweden/epidemiology , Time , Young AdultABSTRACT
OBJECTIVE: To investigate the association between contraceptive effectiveness of Natural Cycles and users' previous choice of contraceptive, and to evaluate the impact of shifting from other methods to Natural Cycles on the risk of unintended pregnancy. SETTING: Natural Cycles mobile application. PARTICIPANTS: 16 331 Natural Cycles users in Sweden for the prevention of pregnancy. OUTCOME MEASURES: Risk of unintended pregnancy. STUDY DESIGN: Real world evidence was collected from Natural Cycles users regarding contraceptive use prior to using Natural Cycles and sexual activity while using Natural Cycles. We calculated the typical use 1-year Pearl Index (PI) and 13-cycle failure rate of Natural Cycles for each cohort. The PI was compared with the population PI of their stated previous methods. RESULTS: For women who had used condoms before, the PI of Natural Cycles was the lowest at 3.5±0.5. For women who had used the pill before, the PI of Natural Cycles was the highest at 8.1±0.6. The frequency of unprotected sex on fertile days partially explained some of the observed variation in PI between cohorts. 89% of users switched to Natural Cycles from methods with higher or similar reported PIs. CONCLUSION: The effectiveness of Natural Cycles is influenced by previous contraceptive choice and this should be considered when evaluating the suitability of the method for the individual. We estimate that Natural Cycles usage can reduce the overall likelihood of having an unintended pregnancy by shifting usage from less effective methods.
Subject(s)
Contraception Behavior , Contraception/methods , Family Planning Services/methods , Menstrual Cycle , Mobile Applications , Pregnancy, Unplanned , Safe Sex , Adolescent , Adult , Condoms , Contraceptive Agents , Female , Fertility , Humans , Middle Aged , Pregnancy , Sweden , Young AdultABSTRACT
OBJECTIVE: The use of inferior vena cava (IVC) filters for prevention of venous thromboembolism (VTE) in bariatric surgery is a contentious issue. We aim to review the evidence for the use of IVC filters in bariatric surgical patients, describe trends in practice, and discuss challenges in developing evidence-based guidelines. BACKGROUND: The incidence of VTE in modern bariatric procedures with traditional methods of thromboprophylaxis, such as sequential calf compression devices and perioperative low molecular weight heparin, is approximately 2%. METHODS: A systematic review of the literature was conducted according to PRISMA guidelines. We searched Medline up until July 2013 with the terms "bariatric filter" and "gastric bypass filter." Two investigators independently screened search results according to an agreed list of eligibility criteria. RESULTS: Eighteen studies were included. There were no randomized controlled trials. Data from controlled cohort studies suggest that those who undergo IVC filter insertion preoperatively may be at higher risk of developing deep vein thrombosis (DVT) and pulmonary embolism (PE). A small cohort of patients with multiple risk factors for VTE benefitted from reduced PE-related mortality after preoperative IVC filter insertion. Data from 12 case series reporting VTE outcomes from a total of 497 patients who underwent preoperative IVC filter insertion demonstrated DVT rates of 0% to 20.8% and PE rates ranging from 0% to 6.4%. CONCLUSIONS: Published data reporting the safety and efficacy of IVC filter use in bariatric surgical patients is highly heterogeneous. There is no evidence to suggest that the potential benefits of IVC filters outweigh the significant risks of therapy.
Subject(s)
Bariatric Surgery/adverse effects , Obesity, Morbid/surgery , Vena Cava Filters , Venous Thromboembolism/prevention & control , Equipment Safety , Humans , Risk Factors , Vena Cava Filters/adverse effectsABSTRACT
BACKGROUND: Obstructive sleep apnoea (OSA) is a well-recognised complication of obesity. Non-surgical weight loss (medical, behavioural and lifestyle interventions) may improve OSA outcomes, although long-term weight control remains challenging. Bariatric surgery offers a successful strategy for long-term weight loss and symptom resolution. OBJECTIVES: To comparatively appraise bariatric surgery vs. non-surgical weight loss interventions in OSA treatment utilising body mass index (BMI) and apnoea-hypopnoea index (AHI) as objective measures of weight loss and apnoea severity. METHODS: A systematic literature review revealed 19 surgical (n = 525) and 20 non-surgical (n = 825) studies reporting the primary endpoints of BMI and AHI before and after intervention. Data were meta-analysed using random effects modelling. Subgroup analysis, quality scoring and risk of bias were assessed. RESULTS: Surgical patients had a mean pre-intervention BMI of 51.3 and achieved a significant 14 kg/m(2) weighted decrease in BMI (95%CI [11.91, 16.44]), with a 29/h weighted decrease in AHI (95%CI [22.41, 36.74]). Non-surgical patients had a mean pre-intervention BMI of 38.3 and achieved a significant weighted decrease in BMI of 3.1 kg/m(2) (95%CI [2.42, 3.79]), with a weighted decrease in AHI of 11/h (95%CI [7.81, 14.98]). Heterogeneity was high across all outcomes. CONCLUSIONS: Both bariatric surgery and non-surgical weight loss may have significant beneficial effects on OSA through BMI and AHI reduction. However, bariatric surgery may offer markedly greater improvement in BMI and AHI than non-surgical alternatives. Future studies must address the lack of randomised controlled and comparative trials in order to confirm the exact relationship between metabolic surgery and non-surgical weight loss interventions in OSA resolution.
Subject(s)
Bariatric Surgery , Life Style , Obesity, Morbid/therapy , Sleep Apnea, Obstructive/therapy , Weight Loss , Body Mass Index , Humans , Obesity, Morbid/complications , Obesity, Morbid/surgery , Sleep Apnea, Obstructive/etiology , Sleep Apnea, Obstructive/surgery , Treatment OutcomeABSTRACT
BACKGROUND: Fundoplication is a leading application of robotic surgery in children, yet the learning curve for this procedure (RF) remains ill-defined. This study aims to identify various learning curve transition points, using cumulative summation (CUSUM) analysis. METHODS: A prospective database was examined to identify RF cases undertaken during 2006-2014. Time-based surgical process outcomes were evaluated, as well as clinical outcomes. RESULTS: A total of 57 RF cases were included. Statistically significant transitions beyond the learning phase were observed at cases 42, 34 and 37 for docking, console and total operating room times, respectively. A steep early learning phase for docking time was overcome after 12 cases. There were three Clavien-Dindo grade ≥ 3 complications, with two patients requiring redo fundoplication. CONCLUSIONS: We identified numerous well-defined learning curve trends to affirm that experience confers significant temporal improvements. Our findings highlight the value of the CUSUM method for learning curve evaluation.
Subject(s)
Fundoplication/methods , Gastroesophageal Reflux/surgery , Robotic Surgical Procedures/methods , Adolescent , Child , Child, Preschool , Databases, Factual , Female , Fundoplication/adverse effects , Fundoplication/statistics & numerical data , Humans , Infant , Infant, Newborn , Learning Curve , Male , Postoperative Complications/etiology , Prospective Studies , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/statistics & numerical data , Treatment OutcomeABSTRACT
BACKGROUND: Diagnosis of vascular injury in pediatric trauma is challenging as clinical signs may be masked by physiologic compensation. We aimed to (1) investigate the prevalence of noniatrogenic pediatric venous injuries, (2) discuss options in management of traumatic venous injury, and (3) investigate mortality from venous injury in pediatric trauma. Our objective was to provide the practicing clinician with a summary of the published literature and to develop an evidence-based guide to the diagnosis and management of traumatic venous injuries in children. METHODS: A systematic review of published literature (PubMed) describing noniatrogenic traumatic venous injury in the pediatric population (<17 years) was performed according to PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] guidelines. Data were retrieved systematically under the following headings: Study Design, Population Demographics (dates of recruitment, mean age, mechanism of injury), Diagnostic Approach, Vessel Injured, Management (operative technique), and Mortality. RESULTS: Thirteen articles were included in this systematic review. In total, 508 noniatrogenic traumatic venous injuries were reported in children between the year 1957 and present day. Mechanisms of injury included blunt trauma from seat belt-related injury and fall from height or penetrating trauma from gunshot and foreign object. Injury to the inferior vena cava was most frequently reported, followed by femoral vein and internal jugular injuries. Primary repair was the most frequently reported technique for surgical repair (38%), followed by ligation (25%) and end-to-end anastomosis (15%). Mortality in pediatric trauma patients who had venous injury was reported as 0% to 67% in published series, highest in the series in which the most frequently reported injury was of the inferior vena cava. CONCLUSION: Traumatic venous injury in the pediatric population is uncommon but may be associated with significant morbidity and mortality. Intra-abdominal venous injuries are associated with high mortality from exsanguination. Early diagnosis and intervention are therefore essential in such cases. LEVEL OF EVIDENCE: Systematic review, level IV.
Subject(s)
Veins/injuries , Child , Evidence-Based Medicine , Humans , Mortality , Prevalence , Veins/surgerySubject(s)
Emphysema , Pyelonephritis , Adult , Emphysema/diagnosis , Emphysema/therapy , Humans , Male , Pyelonephritis/diagnosis , Pyelonephritis/therapyABSTRACT
Vancomycin-induced thrombocytopenia is a rare side effect of a commonly used drug that may cause life-threatening disease. A 51-year-old man was treated for an episode of acute severe alcohol-induced pancreatitis complicated by development of a peripancreatic fluid collection. He developed fever of unknown origin and was treated with intravenous vancomycin and piperacillin with tazobactam. On day 6 of vancomycin therapy his platelet count dropped to 46×10(9)/L (237×10(9)/L on day 1 of treatment) and by day 8 of therapy platelets had fallen to a nadir of 9×10(9)/L. The patient at this stage displayed a florid purpuric rash and haematoma formation on attempted intravenous cannulation. A clinical diagnosis of vancomycin-induced thrombocytopaenia was made and the drug withdrawn. After 3 days a significant improvement in the platelet count was noted, rising to 56 × 10(9)/L. Immunofluorescence testing (PIFT) ruled out teicoplanin and heparin as causes of drug-induced thrombocytopenia.