Relevant analyses
AltraBio offers its expertise in statistics to support your clinical research projects from conception to publication.
Our statisticians have extensive experience in the analysis of medical data covering different therapeutic areas including (but not limited to) neuropsychiatry, neurosciences, pulmonology, immunology, dermatology, cardiology and rheumatology.
We adapt our solutions to the specific needs of our clients: human and veterinary pharmaceutical companies, medical device manufacturers, biotechs, cosmetic and nutritional industries and academic laboratories, from the development phases to the “Post Market Clinical Folow up”.
Study design
- Sample size and power calculation
- Writing of the synopsis
- Definition of the analysis methodology
- Development of the Statistical Analysis Plan
Data collection
- Support for writing the Data Management Plan
- Selection of the eCRF
Data processing
- Data extraction
- Formatting in accordance with the standards (CDISC, …)
- Data correction and cleaning (atypical data, missing data, …)
Data Analysis and valorization
- Descriptive methods, comparative analyses, …
- Construction of explanatory or predictive models, …
- Delivery of statistical reports in the form of a pdf or of a dynamic web page, processing algorithms
- Writing of abstracts, posters, research articles
Our Publications In Medical Data Analysis
2021
Boussuges, Alain; Finance, Julie; Chaumet, Guillaume; Brégeon, Fabienne
Diaphragmatic motion recorded by M-mode ultrasonography: limits of normality Journal Article
In: ERJ Open Res, vol. 7, no. 1, 2021, ISSN: 2312-0541.
@article{pmid33778044,
title = {Diaphragmatic motion recorded by M-mode ultrasonography: limits of normality},
author = {Alain Boussuges and Julie Finance and Guillaume Chaumet and Fabienne Brégeon},
doi = {10.1183/23120541.00714-2020},
issn = {2312-0541},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {ERJ Open Res},
volume = {7},
number = {1},
abstract = {Chest ultrasonography has proven to be useful in the diagnosis of diaphragm dysfunction. The aim of the present study was to determine the normal values of the motion of both hemidiaphragms recorded by M-mode ultrasonography. Healthy volunteers were studied while in a seated position. Diaphragmatic excursions and diaphragm profiles were measured during quiet breathing, voluntary sniffing and deep breathing. Diaphragmatic excursions were assessed by M-mode ultrasonography, using an approach perpendicular to the posterior part of the diaphragm. Anatomical M-mode was used for the recording of the complete excursion during deep breathing. The study included 270 men and 140 women. The diaphragmatic motions during quiet breathing and voluntary sniffing were successfully recorded in all of the participants. The use of anatomical M-mode was particularly suitable for measurement of the entire diaphragmatic excursion during deep breathing. The statistical analysis showed that the diaphragmatic excursions were larger in men compared to women, supporting the determination of normal values based on sex. The lower and upper limits of normal excursion were determined for men and women for both hemidiaphragms during the three manoeuvres that were investigated. The lower limits of normal diaphragmatic excursions during deep breathing should be used to detect diaphragmatic hypokinesia, 3.3 and 3.2 cm in women and 4.1 and 4.2 cm in men for the right and the left sides, respectively. The normal values of the diaphragmatic motion and the lower and upper limits of normal excursion can be used by clinicians to detect diaphragmatic dysfunction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chest ultrasonography has proven to be useful in the diagnosis of diaphragm dysfunction. The aim of the present study was to determine the normal values of the motion of both hemidiaphragms recorded by M-mode ultrasonography. Healthy volunteers were studied while in a seated position. Diaphragmatic excursions and diaphragm profiles were measured during quiet breathing, voluntary sniffing and deep breathing. Diaphragmatic excursions were assessed by M-mode ultrasonography, using an approach perpendicular to the posterior part of the diaphragm. Anatomical M-mode was used for the recording of the complete excursion during deep breathing. The study included 270 men and 140 women. The diaphragmatic motions during quiet breathing and voluntary sniffing were successfully recorded in all of the participants. The use of anatomical M-mode was particularly suitable for measurement of the entire diaphragmatic excursion during deep breathing. The statistical analysis showed that the diaphragmatic excursions were larger in men compared to women, supporting the determination of normal values based on sex. The lower and upper limits of normal excursion were determined for men and women for both hemidiaphragms during the three manoeuvres that were investigated. The lower limits of normal diaphragmatic excursions during deep breathing should be used to detect diaphragmatic hypokinesia, 3.3 and 3.2 cm in women and 4.1 and 4.2 cm in men for the right and the left sides, respectively. The normal values of the diaphragmatic motion and the lower and upper limits of normal excursion can be used by clinicians to detect diaphragmatic dysfunction.
Boussuges, Alain; Rives, Sarah; Finance, Julie; Chaumet, Guillaume; Vallée, Nicolas; Risso, Jean-Jacques; Brégeon, Fabienne
Ultrasound Assessment of Diaphragm Thickness and Thickening: Reference Values and Limits of Normality When in a Seated Position Journal Article
In: Front Med (Lausanne), vol. 8, pp. 742703, 2021, ISSN: 2296-858X.
@article{pmid34778304b,
title = {Ultrasound Assessment of Diaphragm Thickness and Thickening: Reference Values and Limits of Normality When in a Seated Position},
author = {Alain Boussuges and Sarah Rives and Julie Finance and Guillaume Chaumet and Nicolas Vallée and Jean-Jacques Risso and Fabienne Brégeon},
doi = {10.3389/fmed.2021.742703},
issn = {2296-858X},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Front Med (Lausanne)},
volume = {8},
pages = {742703},
abstract = { Diagnosing diaphragm dysfunction in the absence of complete paralysis remains difficult. The aim of the present study was to assess the normal values of the thickness and the inspiratory thickening of both hemidiaphragms as measured by ultrasonography in healthy volunteers while in a seated position. Healthy volunteers with a normal pulmonary function test were recruited. The diaphragmatic thickness was measured on both sides at the zone of apposition of the diaphragm to the rib cage during quiet breathing at end-expiration, end-inspiration, and after maximal inspiration. The thickening ratio, the thickening fraction, and the thickness at end-inspiration divided by the thickness at deep breathing were determined. The mean values and the lower and upper limits of normal were determined for men and women. 200 healthy volunteers (100 men and 100 women) were included in the study. The statistical analysis revealed that women had a thinner hemidiaphragm than men on both sides and at the various breathing times studied. The lower limit of normality of the diaphragm thickness measured at end-expiration was estimated to be 1.3 mm in men and 1.1 mm in women, on both sides. The thickening fraction did not differ significantly between men and women. In men, it ranged from 60 to 260% on the left side and from 57 to 200% on the right side. In women, it ranged from 58 to 264% on the left side and from 60 to 229% on the right side. The lower limits of normality of the thickening fraction were determined to be 40 and 39% in men and 39 and 48% in women for the right and left hemidiaphragms, respectively. The upper limit for normal of the mean of both sides of the ratio thickness at end-inspiration divided by the thickness at deep breathing was determined to be 0.78 in women and 0.79 in men. The normal values of thickness and the indexes of diaphragmatic function should help clinicians with detecting diaphragm atrophy and dysfunction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Diagnosing diaphragm dysfunction in the absence of complete paralysis remains difficult. The aim of the present study was to assess the normal values of the thickness and the inspiratory thickening of both hemidiaphragms as measured by ultrasonography in healthy volunteers while in a seated position. Healthy volunteers with a normal pulmonary function test were recruited. The diaphragmatic thickness was measured on both sides at the zone of apposition of the diaphragm to the rib cage during quiet breathing at end-expiration, end-inspiration, and after maximal inspiration. The thickening ratio, the thickening fraction, and the thickness at end-inspiration divided by the thickness at deep breathing were determined. The mean values and the lower and upper limits of normal were determined for men and women. 200 healthy volunteers (100 men and 100 women) were included in the study. The statistical analysis revealed that women had a thinner hemidiaphragm than men on both sides and at the various breathing times studied. The lower limit of normality of the diaphragm thickness measured at end-expiration was estimated to be 1.3 mm in men and 1.1 mm in women, on both sides. The thickening fraction did not differ significantly between men and women. In men, it ranged from 60 to 260% on the left side and from 57 to 200% on the right side. In women, it ranged from 58 to 264% on the left side and from 60 to 229% on the right side. The lower limits of normality of the thickening fraction were determined to be 40 and 39% in men and 39 and 48% in women for the right and left hemidiaphragms, respectively. The upper limit for normal of the mean of both sides of the ratio thickness at end-inspiration divided by the thickness at deep breathing was determined to be 0.78 in women and 0.79 in men. The normal values of thickness and the indexes of diaphragmatic function should help clinicians with detecting diaphragm atrophy and dysfunction.
2020
Patout, Maxime; Gagnadoux, Frédéric; Rabec, Claudio; Trzepizur, Wojciech; Georges, Marjolaine; Perrin, Christophe; Tamisier, Renaud; Pépin, Jean-Louis; Llontop, Claudia; Attali, Valerie; Goutorbe, Frederic; Pontier-Marchandise, Sandrine; Cervantes, Pierre; Bironneau, Vanessa; Portmann, Adriana; Delrieu, Jacqueline; Cuvelier, Antoine; Muir, Jean-François
AVAPS-AE versus ST mode: A randomized controlled trial in patients with obesity hypoventilation syndrome Journal Article
In: Respirology, vol. 25, no. 10, pp. 1073–1081, 2020, ISSN: 1440-1843.
@article{pmid32052923,
title = {AVAPS-AE versus ST mode: A randomized controlled trial in patients with obesity hypoventilation syndrome},
author = {Maxime Patout and Frédéric Gagnadoux and Claudio Rabec and Wojciech Trzepizur and Marjolaine Georges and Christophe Perrin and Renaud Tamisier and Jean-Louis Pépin and Claudia Llontop and Valerie Attali and Frederic Goutorbe and Sandrine Pontier-Marchandise and Pierre Cervantes and Vanessa Bironneau and Adriana Portmann and Jacqueline Delrieu and Antoine Cuvelier and Jean-François Muir},
doi = {10.1111/resp.13784},
issn = {1440-1843},
year = {2020},
date = {2020-10-01},
urldate = {2020-10-01},
journal = {Respirology},
volume = {25},
number = {10},
pages = {1073--1081},
abstract = {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 P CO > 6 kPa, BMI ≥ 30 kg/m , 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, P CO 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 P CO 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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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 P CO > 6 kPa, BMI ≥ 30 kg/m , 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, P CO 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 P CO 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.
METHODS: This is a prospective multicentric randomized controlled trial. Consecutive OHS patients included had daytime P CO > 6 kPa, BMI ≥ 30 kg/m , 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, P CO 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 P CO 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.