Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Response Shift in Sinus Surgery Outcomes

This study has been completed.
Information provided by (Responsible Party):
Greg Davis, University of Washington Identifier:
First received: July 8, 2011
Last updated: December 11, 2013
Last verified: December 2013

The aims of the study are: 1)to assess pre and post-operative Quality of Life (QOL) as measured by the Sino-Nasal Outcomes Test(SNOT)-20 questionnaire and 2)determine the significance of response shift on treatment effect.

This is a prospective cohort study. The investigators will recruit patients who are within a 6 month post-functional endoscopic sinus surgery (FESS) timeframe and completed a pre-operative SNOT-20. The investigators will ask subjects to complete two more SNOT-20 forms and a Transition Quality of Life (QOL) scale. The SNOT-20 forms will be labelled "pre" and "post" operative. The "pre" should be completed based on subject's memory of their condition prior to surgery and "post" based on how they feel now.

Chronic Rhinosinusitis

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Response Shift in Sinus Surgery Outcomes

Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Sino-Nasal Outcome 20 (SNOT-20) [ Time Frame: 6 months post surgery ]
    The SNOT-20 "pre" and "post" surgery will be compared to the pre-surgery SNOT-20

Enrollment: 32
Study Start Date: June 2011
Study Completion Date: June 2013
Primary Completion Date: June 2013 (Final data collection date for primary outcome measure)
post endoscopic sinus surgery for chronic rhinosinusitis
Patients who have undergone functional endoscopic sinus surgery for treatment of chronic rhinosinusitis and completed a pre-surgery SNOT-20

Detailed Description:

Introduction The most common goal of functional endoscopic sinus surgery (FESS) is to improve quality of life (QOL). Changes in QOL or treatment effect can be measured using validated instruments completed by patients. One's perception of QOL is often a dynamic experience and has been shown to be affected by current medical and emotional state. This phenomenon is known as response shift in QOL research and can be measured by using the Then-test. This test asks patients to complete the same pre-operative survey of their symptoms during the post-operative period. This test aims to characterize any changes in one's perception of the pre-operative condition. The aim of this study is to assess the significance of response shift on sinus surgery outcomes measured using the sino-nasal outcome test (SNOT-20), a validated questionnaire used to assess the severity of symptoms related to chronic rhinosinusitis.

Methods This was a prospective cohort study approved by the University of Washington IRB. We approached all patients who underwent FESS for chronic rhinosinusitis from 2010-2012 who completed a pre-operative SNOT-20. We aimed to recruit 30 patients. Patients were mailed 2 SNOT-20 forms and a transition QOL scale at least 6 months after surgery. Patients were instructed to complete 1 SNOT-20 according to their pre-operative symptoms (then-test) and the other according to their post-operative symptoms. The difference between the pre- and post-operative SNOT-20 was calculated which represents the treatment effect, while the difference between the pre-operative SNOT-20 and then-test represents the response shift. A student t-test was used to compare these differences.

Results A total of 32 complete responses were obtained. Using a 0 to 5 SNOT-20 scale, the average treatment effect was -0.96 (p=0.00) and the average response shift was +0.42 (p=0.01). The negative treatment effect signifies an improvement in QOL. The positive response shift signifies that on average, patients thought they were even more symptomatic prior to surgery. The actual treatment effect is the sum of treatment effect and response shift which was -1.38.

Discussion Response shift exists and can be quantified in FESS outcomes. The actual treatment effect was more profound when taking into account response shift, therefore future studies should account for this often unmeasured, potential change in QOL.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Subjects will be surgery patients from Dr. Davis' clinic at the University of Washington. They will have undergone FESS for treatment of CRS.

Inclusion Criteria:

  • age greater than 18 years
  • ICD 9 code for CRS and CPT code for FESS
  • completed a pre-operative SNOT-20 questionnaire
  • within 6 months of surgical treatment
  • pts. of PI

Exclusion Criteria:

  • unable to give informed consent or complete questionnaires written in English due to cognitive impairment, language barriers or severe medical conditions
  • CRS secondary to malignancy
  • incomplete or incorrectly completed pre-operative SNOT-20
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01391910

United States, Washington
University of Washington
Seattle, Washington, United States, 98104
Sponsors and Collaborators
Greg Davis
Principal Investigator: Greg E Davis, MD, MPH University of Washington
  More Information

Responsible Party: Greg Davis, Assistant Professor, University of Washington Identifier: NCT01391910     History of Changes
Other Study ID Numbers: 40578-E/A
Study First Received: July 8, 2011
Last Updated: December 11, 2013

Keywords provided by University of Washington:
rhinosinusitis processed this record on April 21, 2017