Cost-effectiveness of outpatient versus inpatient non-invasive ventilation setup in obesity hypoventilation syndrome: the OPIP trial.

BACKGROUND: Current guidelines recommend that patients with obesity hypoventilation syndrome (OHS) are electively admitted for inpatient initiation of home non-invasive ventilation (NIV). We hypothesised that outpatient NIV setup would be more cost-effective. METHODS: Patients with stable OHS referred to six participating European centres for home NIV setup were recruited to an open-labelled clinical trial. Patients were randomised via web-based system using stratification to inpatient setup, with standard fixed level NIV and titrated during an attended overnight respiratory study or outpatient setup using an autotitrating NIV device and a set protocol, including home oximetry. The primary outcome was cost-effectiveness at 3 months with daytime carbon dioxide (PaCO2) as a non-inferiority safety outcome; non-inferiority margin 0.5 kPa. Data were analysed on an intention-to-treat basis. Health-related quality of life (HRQL) was measured using EQ-5D-5L (5 level EQ-5D tool) and costs were converted using purchasing power parities to £(GBP). RESULTS: Between May 2015 and March 2018, 82 patients were randomised. Age 59±14 years, body mass index 47±10 kg/m2 and PaCO2 6.8±0.6 kPa. Safety analysis demonstrated no difference in ∆PaCO2 (difference -0.27 kPa, 95% CI -0.70 to 0.17 kPa). Efficacy analysis showed similar total per-patient costs (inpatient £2962±£580, outpatient £3169±£525; difference £188.20, 95% CI -£61.61 to £438.01) and similar improvement in HRQL (EQ-5D-5L difference -0.006, 95% CI -0.05 to 0.04). There were no differences in secondary outcomes. DISCUSSION: There was no difference in medium-term cost-effectiveness, with similar clinical effectiveness, between outpatient and inpatient NIV setup. The home NIV setup strategy can be led by local resource demand and patient and clinician preference. TRIAL REGISTRATION NUMBERS: NCT02342899 and ISRCTN51420481.

Oxygen Uptake and Heart Rate On-Kinetics during Prehabilitation in Patients with Scheduled Non-Small Cell Lung Cancer Resection.

BACKGROUND: Oxygen uptake (V̇O2) and heart rate (HR) kinetics during a constant work-rate test (CWRT) are used to evaluate the response to exercise in healthy subjects as well as subjects with various pathologies. OBJECTIVES: This study aimed to explore the feasibility of these measures and their responsiveness to a prehabilitation program in patients with non-small cell lung cancer (NSCLC). METHOD: This study is preregistered (NCT04041297) ancillary analysis of a subgroup of individuals with NSCLC included in the Preo-Dens study (NCT03936764). Thirty individuals performed a moderate-CWRT before and after a 15-session prehabilitation program between July 2019 and April 2021. V̇O2 and HR on-kinetics were extracted from the first 240 s of breath-by-breath data using Box-Jenkins transfer functions. RESULTS: Pre/post V̇O2 on-kinetic feature values were reliable for 25/30 participants, and pre/post HR kinetic feature values were reliable for 19/30. V̇O2 time constant (τ) and mean response time reduced from pre-post prehabilitation (mean difference -7.8 s; 95% CI: -14.6 to -1.0, and -8.4 s; 95% CI: -14.7 to -2.0, respectively). For HR on-kinetics, τ did not change from pre-post prehabilitation (median difference -4.0 s; 95% CI: -36.0 to +11.0). V̇O2 and HR response amplitudes reduced significatively from pre-post prehabilitation (mean difference -38.6 mL/min; 95% CI: -73.3 to -3.9, and -3.1 beats/min; 95% CI: -6.4 to -0.2, respectively). CONCLUSION: V̇O2 on-kinetic analysis during moderate-CWRT is feasible in individuals with scheduled NSCLC resection, and results are responsive to prehabilitation. These results support a true speeding of the adaptation of aerobic metabolism after a 15-session prehabilitation program.

Chest CT scan plus x-ray versus chest x-ray for the follow-up of completely resected non-small-cell lung cancer (IFCT-0302): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: Even after resection of early-stage non-small-cell lung cancer (NSCLC), patients have a high risk of developing recurrence and second primary lung cancer. We aimed to assess efficacy of a follow-up approach including clinic visits, chest x-rays, chest CT scans, and fibre-optic bronchoscopy versus clinical visits and chest x-rays after surgery for resectable NSCLC. METHODS: In this multicentre, open-label, randomised, phase 3 trial (IFCT-0302), patients aged 18 years or older and after complete resection of pathological stage I-IIIA NSCLC according to the sixth edition of the TNM classification were enrolled within 8 weeks of resection from 122 hospitals and tertiary centres in France. Patients were randomly assigned (1:1) to CT-based follow-up (clinic visits, chest x-rays, thoraco-abdominal CT scans, and fibre-optic bronchoscopy for non-adenocarcinoma histology) or minimal follow-up (visits and chest x-rays) after surgery for NSCLC, by means of a computer-generated sequence using the minimisation method. Procedures were repeated every 6 months for the first 2 years and yearly until 5 years. The primary endpoint was overall survival analysed in the intention-to-treat population. Secondary endpoints, also analysed in the intention-to-treat population, included disease-free survival. This trial is registered with ClinicalTrials.gov, NCT00198341, and is active, but not enrolling. FINDINGS: Between Jan 3, 2005, and Nov 30, 2012, 1775 patients were enrolled and randomly assigned to a follow-up group (888 patients to the minimal follow-up group; 887 patients to the CT-based follow-up group). Median overall survival was not significantly different between follow-up groups (8·5 years [95% CI 7·4-9·6] in the minimal follow-up group vs 10·3 years [8·1-not reached] in the CT-based follow-up group; adjusted hazard ratio [HR] 0·95, 95% CI 0·83-1·10; log-rank p=0·49). Disease-free survival was not significantly different between follow-up groups (median not reached [95% CI not estimable-not estimable] in the minimal follow-up group vs 4·9 [4·3-not reached] in the CT-based follow-up group; adjusted HR 1·14, 95% CI 0·99-1·30; log-rank p=0·063). Recurrence was detected in 246 (27·7%) of 888 patients in the minimal follow-up group and in 289 (32·6%) patients of 887 in the CT-based follow-up group. Second primary lung cancer was diagnosed in 27 (3·0%) patients in the minimal follow-up group and 40 patients (4·5%) in the CT-based follow-up group. No serious adverse events related to the trial procedures were reported. INTERPRETATION: The addition of thoracic CT scans during follow-up, which included clinic visits and chest x-rays after surgery, did not result in longer survival among patients with NSCLC. However, it did enable the detection of more cases of early recurrence and second primary lung cancer, which are more amenable to curative-intent treatment, supporting the use of CT-based follow-up, especially in countries where lung cancer screening is already implemented, alongside with other supportive measures. FUNDING: French Health Ministry, French National Cancer Institute, Weisbrem-Benenson Foundation, La Ligue Nationale Contre Le Cancer, and Lilly Oncology. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Effects of exercise training in people with non-small cell lung cancer before lung resection: a systematic review and meta-analysis.

INTRODUCTION: Exercise training before lung resection for non-small cell lung cancer is believed to decrease postoperative complications (POC) by improving cardiorespiratory fitness. However, this intervention lacks a strong evidence base. AIM: To assess the effectiveness of preoperative exercise training compared with usual care on POC and other secondary outcomes in patients with scheduled lung resection. METHODS: A systematic search of randomised trials was conducted by two authors. Meta-analysis was performed, and the effect of exercise training was estimated by risk ratios (RR) and mean differences, with their CIs. Clinical usefulness was estimated according to minimal important difference values (MID). RESULTS: Fourteen studies involving 791 participants were included. Compared with usual care, exercise training reduced overall POC (10 studies, 617 participants, RR 0.58, 95% CI 0.45 to 0.75) and clinically relevant POC (4 studies, 302 participants, Clavien-Dindo score ≥2 RR 0.42, 95% CI 0.25 to 0.69). The estimate of the effect of exercise training on mortality was very imprecise (6 studies, 456 participants, RR 0.66, 95% CI 0.20 to 2.22). The main risks of bias were a lack of participant blinding and selective reporting. Exercise training appeared to improve exercise capacity, pulmonary function and also quality of life and depression, although the clinical usefulness of the changes was unclear. The quality of the evidence was graded for each outcome. CONCLUSION: Preoperative exercise training leads to a worthwhile reduction in postoperative complications. These estimates were both accurate and large enough to make recommendations for clinical practice.

Long-term survival following initiation of home non-invasive ventilation: a European study.

INTRODUCTION: Although home non-invasive ventilation (NIV) is increasingly used to manage patients with chronic ventilatory failure, there are limited data on the long-term outcome of these patients. Our aim was to report on home NIV populations and the long-term outcome from two European centres. METHODS: Cohort analysis including all patients established on home NIV from two European centres between 2008 and 2014. RESULTS: Home NIV was initiated in 1746 patients to treat chronic ventilatory failure caused by (1) obesity hypoventilation syndrome±obstructive sleep apnoea (OHS±OSA) (29.5%); (2) neuromuscular disease (NMD) (22.7%); and (3) obstructive airway diseases (OAD) (19.1%). Overall cohort median survival following NIV initiation was 6.6 years. Median survival varied by underlying aetiology of respiratory failure: rapidly progressive NMD 1.1 years, OAD 2.7 years, OHS±OSA >7 years and slowly progressive NMD >7 years. Multivariate analysis demonstrated higher mortality in patients with rapidly progressive NMD (HR 4.78, 95% CI 3.38 to 6.75), COPD (HR 2.25, 95% CI 1.64 to 3.10), age >60 years at initiation of home NIV (HR 2.41, 95% CI 1.92 to 3.02) and NIV initiation following an acute admission (HR 1.38, 95% CI 1.13 to 1.68). Factors associated with lower mortality were NIV adherence >4 hours per day (HR 0.64, 95% CI 0.51 to 0.79), OSA (HR 0.51, 95% CI 0.31 to 0.84) and female gender (HR 0.79, 95% CI 0.65 to 0.96). CONCLUSION: The mortality rate following initiation of home NIV is high but varies significantly according to underlying aetiology of respiratory failure. In patients with chronic respiratory failure, initiation of home NIV following an acute admission and low levels of NIV adherence are poor prognostic features and may be amenable to intervention.

AVAPS-AE versus ST mode: A randomized controlled trial in patients with obesity hypoventilation syndrome.

BACKGROUND AND OBJECTIVE: Average volume-assured pressure support-automated expiratory positive airway pressure (AVAPS-AE) combines an automated positive expiratory pressure to maintain upper airway patency to an automated pressure support with a targeted tidal volume. The aim of this study was to compare the effects of 2-month AVAPS-AE ventilation versus pressure support (ST) ventilation on objective sleep quality in stable patients with OHS. Secondary outcomes included arterial blood gases, health-related quality of life, daytime sleepiness, subjective sleep quality and compliance to NIV. METHODS: This is a prospective multicentric randomized controlled trial. Consecutive OHS patients included had daytime Pa CO2 > 6 kPa, BMI ≥ 30 kg/m2 , clinical stability for more than 2 weeks and were naive from home NIV. PSG were analysed centrally by two independent experts. Primary endpoint was sleep quality improvement at 2 months. RESULTS: Among 69 trial patients, 60 patients had successful NIV setup. Baseline and follow-up PSG were available for 26 patients randomized in the ST group and 30 in the AVAPS-AE group. At baseline, Pa CO2 was 6.94 ± 0.71 kPa in the ST group and 6.61 ± 0.71 in the AVAPS-AE group (P = 0.032). No significant between-group difference was observed for objective sleep quality indices. Improvement in Pa CO2 was similar between groups with a mean reduction of -0.87 kPa (95% CI: -1.12 to -0.46) in the ST group versus -0.87 kPa (95% CI: -1.14 to -0.50) in the AVAPS-AE group (P = 0.984). Mean NIV use was 6.2 h per night in both groups (P = 0.93). NIV setup duration was shorter in the AVAPS-AE group (P = 0.012). CONCLUSION: AVAPS-AE and ST ventilation for 2 months had similar impact on sleep quality and gas exchange.

Polysomnography versus limited respiratory monitoring and nurse-led titration to optimise non-invasive ventilation set-up: a pilot randomised clinical trial.

Polysomnography (PSG) is recommended for non-invasive ventilation (NIV) set-up in patients with chronic respiratory failure. In this pilot randomised clinical trial, we compared the physiological effectiveness of NIV set-up guided by PSG to limited respiratory monitoring (LRM) and nurse-led titration in patients with COPD-obstructive sleep apnoea (OSA) overlap. The principal outcome of interest was change in daytime arterial partial pressure of carbon dioxide (PaCO2) at 3 months. Fourteen patients with daytime PaCO2 >6 kPa and body mass index >30 kg/m2 were recruited. At 3 months, PaCO2 was reduced by -0.88 kPa (95% CI -1.52 to -0.24 kPa) in the LRM group and by -0.36 kPa (95% CI -0.96 to 0.24 kPa) in the PSG group. These pilot data provide support to undertake a clinical trial investigating the clinical effectiveness of attended limited respiratory monitoring and PSG to establish NIV in patients with COPD-OSA overlap. TRIAL NUMBER: Results, NCT02444806.

Nasal High Flow for Stable Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.

There is a growing body of evidence supporting the use of nasal high flow (NHF) to treat acute respiratory failure, particularly in Chronic Obstructive Pulmonary Disease (COPD) patients. Conversely, there are sparse data evaluating its effects in stable COPD patients.We identified randomized controlled trial comparing the effects of delivering air or oxygen via NHF, compared with delivering the same gas without NHF, in stable COPD patients through a systematic search using MEDLINE, CENTRAL, Science Direct, and others sources until January 2019. Study selection, data extraction and assessment of the risk of bias (using the Cochrane Risk of Bias tool) was performed by two independent authors.We included 6 studies (339 participants). Our meta-analysis showed a significant reduction of arterial carbon dioxide pressure (PaCO2) at long (two studies, MD -3 mmHg, [95% Confidence interval (CI) -4 to -2]) and short-term (two studies, MD -3 mmHg [95% CI -4 to -2]). NHF significantly improved quality of life on the St George's Respiratory Questionnaire (two studies, MD -5 out of 100, [95% CI -8 to -2]). NHF significantly reduced the rate of acute exacerbation at 1 year (one study, rate ratio: 0.6, [95% CI 0.6 to 0.7]). NHF did not significantly improve exercise capacity, hospitalization rate or mortality, but improved breathing pattern.NHF reduced PaCO2, acute exacerbation and improved quality of life in stable COPD patients. Further long-term studies are needed to confirm the present results and provide more data on patient-centered outcome such as quality of life, exacerbation, hospitalization and mortality.

Home-based Neuromuscular Electrical Stimulation as an Add-on to Pulmonary Rehabilitation Does Not Provide Further Benefits in Patients With Chronic Obstructive Pulmonary Disease: A Multicenter Randomized Trial.

OBJECTIVE: To assess the additional effect of a home-based neuromuscular electrical stimulation (NMES) program as an add-on to pulmonary rehabilitation (PR), on functional capacity in subjects with chronic obstructive pulmonary disease (COPD). DESIGN: Single-blind, multicenter randomized trial. SETTING: Three PR centers. PARTICIPANTS: Subjects with severe to very severe COPD (N=73; median forced expiratory volume in 1 second, 1L (25th-75th percentile, 0.8-1.4L) referred for PR. Twenty-two subjects discontinued the study, but only 1 dropout was related to the intervention (leg discomfort). INTERVENTION: Subjects were randomly assigned to either PR plus quadricipital home-based NMES (35Hz, 30min, 5 time per week) or PR without NMES for 8 weeks. MAIN OUTCOME MEASURE: The 6-minute walk test (6MWT) was used to assess functional capacity. RESULTS: Eighty-two percent of the scheduled NMES sessions were performed. In the whole sample, there were significant increases in the distance walked during the 6MWT (P<.01), peak oxygen consumption (P=.02), maximal workload (P<.01), modified Medical Research Council dyspnea scale (P<.01), and Saint George's Respiratory Questionnaire total score (P=.01). There was no significant difference in the magnitude of change for any outcome between groups. CONCLUSIONS: Home-based NMES as an add-on to PR did not result in further improvements in subjects with severe to very severe COPD; moreover, it may have been a burden for some patients.

Home-Based Care Evolution in Chronic Respiratory Failure between 2001 and 2015 (Antadir Federation Observatory).

BACKGROUND: The aetiologies of chronic respiratory failure (CRF) are moving in many western countries. Obesity-Hypoventilation syndrome (OHS) has become one of the most common indications of non-invasive ventilation (NIV) with Chronic Obstructive Pulmonary Diseases (COPD). Long-Term Oxygen Therapy (LTOT) technology is the treatment plan for CRF patients in the new era. OBJECTIVES: This study aimed to assess home-based care evolution in CRF patients on LTOT (LTOT) and/or NIV from the ANTADIR observatory. METHODS: A computerized database from 14 regional facilities was analysed (30% of French home-treated patients). Patient age, sex, aetiology, home respiratory devices were recorded between 2001 and 2015. RESULTS: By the end of 2015, 12,147 CRF patients received LTOT (40%), NIV (24%), LTOT + NIV (23%), continuous positive airway pressure (CPAP; 11%) or LTOT + CPAP (3%). Between 2001 and 2015, we observed a decrease of LTOT (63-40%) in the benefit of NVI ± LTOT (25-47%). Regarding the aetiology, we note a slight decrease in obstructive disease and a significant increase in restrictive disease, mainly due to OHS. The 10-year survival was better on NIV ± LTOT than on LTOT, for overall patients and for both obstructive and restrictive patients. The 10-year survival was better on NIV ± LTOT than on LTOT (35 vs. 10%, p < 0.05). In COPD patients on LTOT, a switch from conventional to new home devices was observed. Stationary LTOT systems were less prescribed, while portable/transportable -system, liquid oxygen and self-filling oxygen were increasingly prescribed. CONCLUSION: Our study confirmed changes in CRF aetiologies and home devices. OHS is now an important indication of NIV. Using new LTOT technologies changed home prescriptions in COPD patients.

Six-minute Stepper Test to Set Pulmonary Rehabilitation Intensity in Patients with COPD - A Retrospective Study.

Pulmonary rehabilitation (PR) improves outcomes in patients with chronic obstructive pulmonary disease (COPD). Optimal assessment includes cardiopulmonary exercise testing (CPET), but consultations are limited. Field tests could be used to individualize PR instead of CPET. The six-minute stepper test (6MST) is easy to set up and its sensitivity and reproducibility have previously been reported in patients with COPD. The aim of this study was to develop a prediction equation to set intensity in patients attending PR, based on the 6MST. The following relationships were analyzed: mean heart rate (HR) during the first (HR1-3) and last (HR4-6) 3 minutes of the 6MST and HR at the ventilatory threshold (HRvt) from CPET; step count at the end of the 6MST and workload at the Ventilatory threshold (VT) (Wvt); and forced expiratory volume in 1 second and step count during the 6MST. This retrospective study included patients with COPD referred for PR who underwent CPET, pulmonary function evaluations and the 6MST. Twenty-four patients were included. Prediction equations were HRvt = 0.7887 × HR1-3 + 20.83 and HRvt = 0.6180 × HR4-6 + 30.77. There was a strong correlation between HR1-3 and HR4-6 and HRvt (r = 0.69, p < 0.001 and r = 0.57, p < 0.01 respectively). A significant correlation was also found between step count and LogWvt (r = 0.63, p < 0.01). The prediction equation was LogWvt = 0.001722 × step count + 1.248. The 6MST could be used to individualize aerobic training in patients with COPD. Further prospective studies are needed to confirm these results.

Morbidity-mortality conference for adverse events associated with totally implanted venous access for cancer chemotherapy.

PURPOSE: Although considered safer than central venous catheters for administration of cancer chemotherapy, totally implanted venous access (TIVA) is associated with adverse events that may impair prognosis and quality of life of patients receiving chemotherapy. Our aim was to assess the feasibility and interest of surveillance of cancer chemotherapy TIVA-adverse events (AE), associated with morbidity-mortality conferences (MMCs) on TIVA-AE. METHODS: We performed a prospective interventional study in two hospitals (a university hospital and a comprehensive care center). For each cancer chemotherapy care pathway within each hospital, we set up surveillance of TIVA-AE and MMC on these events. Patients included in surveillance were those with a TIVA either placed or used for chemotherapy cycles in one of the participating wards. Feasibility of MMC was assessed by the number of MMC meetings that actually took place and the number of participants at each meeting. The interest of MMC was assessed by the number of TIVA-AE identified and analyzed, and the number and type of improvement actions selected and actually implemented. RESULTS: We recorded 0.41 adverse events per 1000 TIVA-day. MMCs were implemented in all care pathways, with sustained pluriprofessional attendance throughout the survey; 39 improvement actions were identified during meetings, and 18 were actually implemented. CONCLUSIONS: Surveillance of TIVA-AE associated with MMC is feasible and helps change practices. It could be useful for improving care of patients undergoing cancer chemotherapy.

An easy-to-use technique to characterize cardiodynamics from first-return maps on ΔRR-intervals.

Heart rate variability analysis using 24-h Holter monitoring is frequently performed to assess the cardiovascular status of a patient. The present retrospective study is based on the beat-to-beat interval variations or ΔRR, which offer a better view of the underlying structures governing the cardiodynamics than the common RR-intervals. By investigating data for three groups of adults (with normal sinus rhythm, congestive heart failure, and atrial fibrillation, respectively), we showed that the first-return maps built on ΔRR can be classified according to three structures: (i) a moderate central disk, (ii) a reduced central disk with well-defined segments, and (iii) a large triangular shape. These three very different structures can be distinguished by computing a Shannon entropy based on a symbolic dynamics and an asymmetry coefficient, here introduced to quantify the balance between accelerations and decelerations in the cardiac rhythm. The probability P111111 of successive heart beats without large beat-to-beat fluctuations allows to assess the regularity of the cardiodynamics. A characteristic time scale, corresponding to the partition inducing the largest Shannon entropy, was also introduced to quantify the ability of the heart to modulate its rhythm: it was significantly different for the three structures of first-return maps. A blind validation was performed to validate the technique.

Enhanced Recovery after Surgery (ERAS) Implementation and Barriers among Healthcare Providers in France: A Cross-Sectional Study.

The implementation of Enhanced Recovery After Surgery (ERAS) is a challenge for healthcare systems, especially in case of patients undergoing major surgery. Despite a proven significant reduction in postoperative complications and hospital lengths of stay, ERAS protocols are inconsistently used in real-world practice, and barriers have been poorly described in a cohort comprising medical and paramedical professionals. This study aims to assess the proportion of French healthcare providers who practiced ERAS and to identify barriers to its implementation amongst those surveyed. We conducted a prospective cross-sectional study to survey healthcare providers about their practice of ERAS using an online questionnaire. Healthcare providers were contacted through hospital requests, private hospital group requests, professional corporation requests, social networks, and personal contacts. The questionnaire was also designed to explore barriers to ERAS implementation. Identified barriers were allocated by two independent assessors to one of the fourteen domains of the Theoretical Domains Framework (TDF), which is an integrative framework based on behavior change theories that can be used to identify issues relating to evidence on the implementation of best practice in healthcare settings. One hundred and fifty-three French healthcare providers answered the online questionnaire (76% female, median age 35 years (IQR: 29 to 48)). Physiotherapists, nurses, and dieticians were the most represented professions (31.4%, 24.2%, and, 14.4%, respectively). Amongst those surveyed, thirty-one practiced ERAS (20.3%, 95%CI: 13.9 to 26.63). Major barriers to ERAS practice were related to the "Environmental context and resources" domain (57.6%, 95%CI: 49.5-65.4), e.g., lack of professionals, funding, and coordination, and the "Knowledge" domain (52.8%, 95%CI: 44.7-60.8), e.g., ERAS unawareness. ERAS in major surgery is seldom practiced in France due to the unfavorable environment (i.e., logistics issues, and lack of professionals and funding) and a low rate of procedure awareness. Future studies should focus on devising and assessing strategies (e.g., education and training, collaboration, institutional support, the development of healthcare networks, and leveraging telehealth and technology) to overcome these barriers, thereby promoting the wider implementation of ERAS.

Individuality of breathing patterns in patients under noninvasive mechanical ventilation evidenced by chaotic global models.

Autonomous global models based on radial basis functions were obtained from data measured from patients under noninvasive mechanical ventilation. Some of these models, which are discussed in the paper, turn out to have chaotic or quasi-periodic solutions, thus providing a first piece of evidence that the underlying dynamics of the data used to estimate the global models are likely to be chaotic or, at least, have a chaotic component. It is explicitly shown that one of such global models produces attractors characterized by a Horseshoe map, two models produce toroidal chaos, and one model produces a quasi-periodic regime. These topologically inequivalent attractors evidence the individuality of breathing profiles observed in patient under noninvasive ventilation.

Video abstracts are associated with an increase in research reports citations, views and social attention: a cross-sectional study.

Video abstracts have been proposed as a tool to disseminate research through to social networks. However, its association with metrics of research dissemination has not been adequately investigated, particularly in the field of medical research. The aim of this study was to assess the association between video abstracts and citations, views and Altmetric Attention Score (AAS) of research papers. A cross-sectional study of research reports published in the New England Journal of Medicine (NEJM) over a 3-year period was conducted. An inverse binomial regression was used to assess factors associated with citations, views and AAS. The model included the presence of video abstracts as well as other independent covariables as potential confounding factors. 500 research reports were included in the analysis and 152 benefited from a video abstract. The median time from publication was 3.0 (2.2 to 3.6) years and 72% were RCTs. Research reports published with a video abstract were associated with an increase in citations (IRR 1.15), although this estimate came with uncertainty ranging from virtually no effect to a worthwhile effect (95% CI 0.98 to 1.35). There were also associated with a worthwhile increase in views (IRR 1.35, 95% CI 1.18 to 1.54) as well as with an increase in AAS (IRR 1.25, 95% CI 1.08 to 1.44). To conclude, video abstracts are associated with a worthwhile increase in the number of views of research reports. They are also associated with an increase in citations and social attention, although the association may be small. Supplementary Information: The online version contains supplementary material available at 10.1007/s11192-023-04675-9.