Condition category
Signs and Symptoms
Date applied
19/03/2019
Date assigned
22/03/2019
Last edited
22/03/2019
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aim
Obstructive sleep apnea syndrome (OSAS) affects nearly one billion people worldwide. Specific screening tools are not available to identify OSAS in nocturnal polyuria (NP) populations. To develop a screening tool for detecting severe OSAS in patients presenting with NP.

Who can participate?
Men aged over 18 years who have nocturia due to nocturnal polyuria

What does the study involve?
This is a retrospective review of patients diagnosed with nocturia due to nocturnal polyuria and screened for obstructive sleep apnea syndrome between 2016 and 2018. The researchers gathered data about the collection of data, the characteristic of patients and their follow up. This is done to develop a screening tool for detecting severe OSAS in patients presenting with nocturnal polyuria.

What are the possible benefits and risks of participating?
There are no benefits or risks for participating.

Where is the study run from?
Clinique Pasteur, Toulouse

When is the study starting and how long is it expected to run for?
January 2016 to December 2018.

Who is funding the study?
The Clinique Pasteur

Who is the main contact?
Dr Vincent Misrai
vmisrai@clinique-pasteur.com

Trial website

Contact information

Type

Scientific

Primary contact

Dr Vincent Misrai

ORCID ID

http://orcid.org/0000-0003-2029-0650

Contact details

Clinique Pasteur
45
avenue de Lombez
Toulouse
31300
France
+33562211652
vmisrai@clinique-pasteur.com

Additional identifiers

EudraCT number

Nil known

ClinicalTrials.gov number

Nil known

Protocol/serial number

2212434

Study information

Scientific title

A tool for severe obstructive sleep apnea syndrome screening in patients with unexplained nocturnal polyuria

Acronym

Study hypothesis

Obstructive sleep apnea syndrome (OSAS) affects nearly one billion people worldwide. Specific screening tools are not available to identify OSAS in nocturnal polyuria (NP) populations. Our aim was to develop a screening tool for detecting severe OSAS using a large single-institutional dataset of patients referred for nocturnal polyuria.

Ethics approval

Approved 17/01/2016, Commission nationale de l'informatique et des libertés (CNIL, 3 Place de Fontenoy, TSA 80715, 75334 PARIS CEDEX 07, France; +33(0)153732222), ref: 2212434

Study design

Prospective observational cohort study

Primary study design

Observational

Secondary study design

Cohort study

Trial setting

Hospitals

Trial type

Screening

Patient information sheet

No participant information sheet available

Condition

Nocturia

Intervention

Medical records of patients diagnosed with nocturia due to nocturnal polyuria and screened for obstructive sleep apnea syndrome (OSAS) with a sleep study (overnight polygraphy)
Patients diagnosed with severe OSAS were compared to a group of patients without OSAS or diagnosed with mild to moderate OSAS. Clinical predictive factors associated with severe OSAS were identified via logistic regression. A score combining the main predictors was
created and evaluated.

Intervention type

Other

Phase

Drug names

Primary outcome measure

To design and validate a new “score” (the Clinique Pasteur score) to detect severe OSAS in patients with unexplained nocturnal polyuria.

Secondary outcome measures

To validate this “score” (internal validation)

Development of the score
Step 1: logistic regression model
The first step in constructing the score was to perform a multivariate logistic regression analysis. All variables associated with severe OSAS according to a p value <0.2 in the logistic regression were selected. For continuous variables, the log-linearity assumption had to be fulfilled to ensure the validity of the model. If this assumption was not fulfilled, the continuous variable was categorized. The continuous variables included in the final model were age and BMI, and the assumption of log-linearity was not fulfilled. The thresholds chosen for the categorization of BMI were 25 kg/m2 and 30 kg/m2 according to anthropometric definition (normal/overweight/obese). The threshold for age (70 years) was much more arbitrary and was choose for sample size and powerful of the prediction reasons. The results of the model are expressed by means of odd-ratio together with their 95% confidence intervals computed by Wald’s methods.
The performance was assessed by the rate of prediction error, the receiver operating characteristic (ROC) curve and a graphical illustration of the specificity/sensitivity of the model. The area under this curve (AUC) and its 95% confidence interval computed by bootstrap procedure (2000 replicates) indicated the predictive performances of the model.
The internal validity of the model was investigated by splitting the database into two cohorts: a learning cohort (65% of the sample size) to create the model and a validation cohort (35% of the sample size) to assess. Individuals were randomly assigned to one of the cohorts. The predictive performance was assessed by the rate of prediction error and ROC curves.
Step 2: construction of the score
As the variables involved in the model were discrete, it was possible to construct a simplified score by choosing intergern proportional values to rounded values of the logistic regression coefficients. This simplified score was constructed by using the connection between the values of the score and the predicted probabilities for a patient presenting with unexplained NP to have a severe OSAS. The choice of the cut-off score was made according to the plot of PPV and NPV as a function of the threshold.

Overall trial start date

20/01/2016

Overall trial end date

31/12/2018

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

1. Diagnosed with a nocturia due to nocturnal polyuria
2. Screened for sleep apnea syndrome with overnight polygraphy

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

200

Participant exclusion criteria

1. Patients presenting with the following potential causes of nocturnal polyuria:
1.1 Diabetes insipidus
1.2 Uncontrolled diabetes mellitus (defined by a serum glucose level > 200 mg/dL)
1.3 Severe renal impairment (defined by a glomerular filtration rate of <30 ml/min)
1.4 Hart failure
1.5 Oedematous state

Recruitment start date

21/01/2016

Recruitment end date

31/12/2018

Locations

Countries of recruitment

France

Trial participating centre

Clinique Pasteur
45 avenue de Lombez
Toulouse
31300
France

Sponsor information

Organisation

Clinique Pasteur

Sponsor details

45 avenue de Lombez
Toulouse
31300
France
+33562213326
vmisrai@clinique-pasteur.com

Sponsor type

Hospital/treatment centre

Website

Funders

Funder type

Hospital/treatment centre

Funder name

Clinique Pasteur

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal.

IPD sharing statement: the data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date

31/12/2019

Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

22/03/2019: Trial’s existence confirmed by funder