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Information for Reviewers

Text in black is part of the template used to create this document and is not under review. Please review the blue text; this text represents the changes made to the template that are specific to this QRS instrument.


Epworth Sleepiness Scale (ESS)

CDISC ReferenceQuestionnaire Supplement to the Study Data Tabulation Model Implementation Guide for Human Clinical Trials
QRS Short Name


QRS Permission StatusApproved
TeamCDISC Questionnaires, Ratings, and Scales (QRS) Subteam
Supplement Version1.1
NotesThis supplement is intended to be used with other CDISC user guides for specific therapeutic/disease areas and follows the CDISC Study Data Tabulation Model Implementation Guide for Human Clinical trials.

Revision History

DateVersionSummary of Changes
2019-06-16 QRSSUPP-163 - Getting issue details... STATUS 1.1
  • Converted this version to the CDISC Wiki.
  • Added the total score to QRS terminology based on sponsors receiving it as eData. This is considered as captured data when received as eData.
  • The QSEVAL variable was removed from this supplement, because it is not captured on the CRF and no assumptions are made on the potential values.
2013-06-261.0Initial Final Version

© 2019 Clinical Data Interchange Standards Consortium, Inc. All rights reserved. 

1 Introduction

This document describes the CDISC implementation of the Epworth Sleepiness Scale (ESS) questionnaire.

CDISC does not modify QRS instruments to meet Clinical Data Acquisition Standards Harmonization (CDASH) case report form (CRF) standards.

The representation of data collected for this questionnaire is based on the Study Data Tabulation Model Implementation Guide (SDTMIG) Questionnaires (QS) domain model, which can be found at the CDISC website at:

These specific implementation details for this questionnaire are meant to be used in conjunction with the SDTMIG. All CDISC QRS documentation packages can be found on the CDISC website at:

The CDISC Intellectual Property Policy can be found on the CDISC website at:

1.1 Representations and Warranties, Limitations of Liability, and Disclaimers

This document is a supplement to the SDTMIG for Human Clinical Trials and is covered under Appendix F of that document, which describes representations, warranties, limitations of liability, and disclaimers. Please see Appendix F of the SDTMIG for a complete version of this material.

CDISC specifies how to structure the data that has been collected in a database, not what should be collected or how to conduct clinical assessments or protocols.

2 Copyright Status

Murray W. Johns owns the copyright for the ESS instrument and has granted CDISC permission to include this supplement in the CDISC library of QRS data standards supplements. Hence, CDISC developed QSTESTCD and QSTEST for each item based on the actual text on the questionnaire. There may be many versions of this instrument in the public domain or copyrighted. CDISC has chosen to use this version as the data standard.

The CDISC documentation of this instrument consists of: (1) controlled terminology, (2) standard database structure with examples, and (3) CRF(s) annotated with the CDISC SDTMIG variables with submission values (ESS Annotated CRF). 

Note: CDISC controlled terminology is maintained by National Cancer Institute (NCI) Enterprise Vocabulary Services (EVS). The most recent version should be accessed through the CDISC website (

CDISC has developed this documentation at no cost to the copyright holder or any additional cost to users of the instrument beyond the normal licensing fees charged by the copyright holder.

CDISC acknowledges Dr. Murray W. Johns for the approval to include the ESS in the CDISC data standards.

References for the Epworth Sleepiness Scale (ESS):

3 The QS Domain Model

3.1 Assumptions for the QS Domain Model

All assumptions and business rules described in the SDTMIG QS domain are applicable to this supplement. Additional assumptions specific to the ESS are listed below.

The ESS is a multiple-choice questionnaire that clinicians may use to provide an assessment of a subject’s general level of daytime sleepiness. It is an 8-item, self-administered questionnaire. Subjects rate the 8 items on a scale of 0-3.

  1. The scale points include a numeric rating (0-3) and a definition of what is represented by the rating (e.g., 0 = "would never doze"). For the ESS, QSORRES is populated with the text description; the numeric rating is represented in the standardized character and numeric result variables QSSTRESC and QSSTRESN.

  2. The ESS is evaluated by the subject based on “usual way of life in recent times”. The time period of evaluation for the ESS is populated in the QSEVINTX field when the evaluation interval can be precisely described as duration. The evaluation interval for the ESS is "RECENT TIMES".

  3. The ESS instrument includes a total score that is not included on the CRF, but which is described on the website ( This total score is considered as captured data when provided as part of eData and is not QRSSUPP-155 - Getting issue details... STATUS considered as derived in the example below.

    1. If operationally defined by the sponsor, it is the sponsor's responsibility to set the -DRVFL flag based on their eCRF process to derive subtotals and total scores. An investigator-derived score written on a CRF will be considered a captured score and not flagged. When subtotal and total scores are derived by the sponsor, the derived flag (-DRVFL) is set to Y. However, when the subtotal and total scores are received from a central provider or vendor, the value would go into --ORRES and --DRVFL would be null (see SDTMIG Section, Origin Metadata for Variables).

  4. Terminology

    1. QSCAT, QSTESTCD, and QSTEST values are included in CDISC Controlled Terminology.

    2. A full list of value sets for the result field is provided in Section 4, SDTM Mapping Strategy.

3.2 Example for the ESS QS Domain Model

The ESS example below QRSSUPP-162 - Getting issue details... STATUS shows the terminology used to implement the instrument in the QS domain. This example shows the data for 1 subject QRSSUPP-161 - Getting issue details... STATUS collected at the baseline visit for the ESS instrument. The example uses CDISC Controlled Terminology for QSTESTCD, QSTEST, and QSCAT. All original results are represented with preferred terminology in QSORRES. This result is then transformed into the standard numeric score in QSSTRESN and a character representation of the standard numeric score in QSSTRESC.

We are unable to make the example show blue in the Wiki. All examples are updated for each QRS instrument so we ask that you please review the example below.

The table represents the questions from the ESS form. Row 9 represents the "Total Score" added to the example. 



1STUDYXQSP00011ESS0101ESS01-Sitting and ReadingESSslight chance of dozing11Y12013-04-11RECENT TIMES
2STUDYXQSP00012ESS0102ESS01-Watching TVESSmoderate chance of dozing22Y12013-04-11RECENT TIMES
3STUDYXQSP00013ESS0103ESS01-Sitting Inactive in a Public PlaceESSwould never doze00Y12013-04-11RECENT TIMES
4STUDYXQSP00014ESS0104ESS01-Passenger for Hour Without BreakESSslight chance of dozing11Y12013-04-11RECENT TIMES
5STUDYXQSP00015ESS0105ESS01-Lying Down to Rest In AfternoonESSslight chance of dozing11Y12013-04-11RECENT TIMES
6STUDYXQSP00016ESS0106ESS01-Sitting and Talking to SomeoneESShigh chance of dozing33Y12013-04-11RECENT TIMES
7STUDYXQSP00017ESS0107ESS01-Sitting Quietly After LunchESSwould never doze00Y12013-04-11RECENT TIMES
8STUDYXQSP00018ESS0108ESS01-In Car Stopped Few Minutes TrafficESSmoderate chance of dozing22Y12013-04-11RECENT TIMES
9STUDYXQSP00019ESS0109ESS01-Total ScoreESS101010Y12013-04-11RECENT TIMES

4 SDTM Mapping Strategy

This section is used for reference regarding the CRF data capture and to understand the alignment of the instrument to the SDTM QS domain. It also provides guidance on how the result variables (QSORRES, QSSTRESC, and QSSTRESN) should be populated.

QSTESTCD = "ESS0101" QSTEST = "ESS01-Sitting and Reading" to

QSTESTCD = "ESS0108" QSTEST = "ESS01-In Car Stopped Few Minutes Traffic"


would never doze



slight chance of dozing



moderate chance of dozing



high chance of dozing



End of Document

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