User Manual: Inquisit Yale Food Addiction Scale (YFAS)


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									YALE FOOD ADDICTION SCALE
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 04-14-2016
last updated:  11-01-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 11-01-2023 Millisecond Software

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BACKGROUND INFO 	
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This script implements a computerized version of the Yale Food Addiction Scale.
The Yale Food Addiction Scale was developed to identify people who exhibit dependence on high fat/high sugar foods.

Reference:

Gearhardt, A.N., Corbin, W.R., & Brownell, K.D. (2009). Preliminary validation of the Yale Food Addiction Scale. Appetite, 52, 430-436.

Ashley N. Gearhardt, William R. Corbin, Kelly D. Brownell. (2012) . Yale Food Addiction Scale (YFAS). 
Measurement Instrument Database for the Social Science. Retrieved from www.midss.ie

Instrument Authors: Ashley N. Gearhardt, William R. Corbin, Kelly D. Brownell
http://www.midss.org/content/yale-food-addiction-scale-yfas

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OVERVIEW
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A questionnaire with 25 questions with different response scales, self-report											  

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DURATION 
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the default set-up of the script takes appr. 4 minutes to complete

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DATA OUTPUT DICTIONARY
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The fields in the data files are:

(1) Raw data file: 'yalefoodaddictionscale.iqdat'

date, time:						date and time script was run with the current group/subjectnumber 
subject, group, session:	  		with the current subject/groupnumber/session id
build:							the Inquisit build 

q*_response:					response given (in assigned values)
								Scale:
								q1-q16: 0 (never) - 4 (4 or more times)
								q17-q24: 0 (no); 1 (yes)
								q25: 0 (1 or fewer times) - 4 (5 or more times)
								No reversed scored questions
									
q*_latency:						how much time (in ms) the participant spent on the surveyPage with this particular 
								question (the last time this particular surveyPage was visited)

(2) Summary data file: 'yalefoodaddictionscale_summary.iqdat' (Inquisit Lab: one data file per participant)

inquisit.version:				Inquisit version run
computer.platform:				the platform the script was run on (win/mac/ios/android)
startDate:						date script was run
startTime:						time script was started
subjectId:						assigned subject id number
groupId:						assigned group id number
sessionId:						assigned session id number
elapsedTime:					time it took to run script (in ms); measured from onset to offset of script
completed:						0 = script was not completed (prematurely aborted); 
								1 = script was completed (all conditions run)	

scales:							1 = criterion met; 
								0 = criterion not met 

amountsTaken:					Substance taken in larger amount and for longer period than intended; Questions #1, #2, #3
unsuccessfulQuits:				Persistent desire or repeated unsuccessful attempts to quit; Questions #4, #22, # 24, #25
timeSpentObtaining:				Much time/activity to obtain, use, recover; Questions #5, #6, #7
reducedActivities:				Important social, occupational, or recreational activities given up or reduced; Questions #8, #9, #10, #11
useDespiteKnowledge:			Use continues despite knowledge of adverse consequences (e.g., failure to fulfill role obligation, use when physically hazardous); Question #19
tolerance:						Tolerance (marked increase in amount; marked decrease in effect); Questions #20, #21
withdrawal:						Characteristic withdrawal symptoms; substance taken to relieve withdrawal; Questions #12, #13, #14
clinicalSignificance:			Use causes clinically significant impairment or distress; Questions #15, #16
symptomCountScore:				sum of the individual criterion scores (excluding clinical significance) = Symptom count without diagnosis (Range: 0-7)

diagnosisFoodDependence: 		1 = diagnosis met (symptomcount > 3 AND clinical significance = 1); 
								0 = otherwise diagnosis not met
								
q1-q25:							contain the scored responses for question 1-25 according to the scoring guidelines
								NOTE: q17, q18, q23 are not scored - used as primers for other questions
								
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QUESTIONNAIRE SET-UP & SCORING
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25 questions
q1-q16, q25: 5 point Likert Questions
q17-q24: yes/no questions


SCORING (from scoring guidelines: http://www.midss.org/content/yale-food-addiction-scale-yfas):
The following cut-offs were developed for the continuous questions.
0 = criterion not met, 1 = criterion is met
The following questions are scored 0 = (0), 1 = (1): #19, #20, #21, #22
The following question is scored 0 = (1), 1 = (0): #24
The following questions are scored 0 = (0 thru 1), 1 = (2 thru 4): #8, #10, #11
The following questions are scored 0 = (0 thru 2), 1 = (3 & 4): #3, #5, #7, #9, #12, #13,
#14, #15, #16
The following questions are scored 0 = (0 thru 3), 1 = (4): #1, #2, #4, #6
The following questions are scored 0 = (0 thru 4), 1 = (5): #25
NOTE: q17, q18, q23 are not scored - used as primers for other questions

NORMS (from scoring guidelines: http://www.midss.org/content/yale-food-addiction-scale-yfas):
Norms (undergraduates)
Diagnosis of Food Dependence – 11.6%
Median Symptom Count Score – 1.0
Withdrawal – 16.3%
Tolerance – 13.5%
Continued Use Despite Problems – 28.3%
Important Activities Given Up – 10.3%
Large Amounts of Time Spent – 24.0%
Loss of Control – 21.7%
Have Tried Unsuccessfully to Cut Down or Worried About Cutting Down – 71.3%
Clinically Significant Impairment - 14%