Transcript A comparison of 3 withdrawal scales Jean-François ETTER, PhD Institute of social and preventive medicine University of Geneva, Switzerland John R.

A comparison of 3 withdrawal scales
Jean-François ETTER, PhD
Institute of social and preventive medicine
University of Geneva, Switzerland
John R. HUGHES, MD
Departments of Psychiatry and Psychology,
University of Vermont, Burlington, VT, USA
SRNT Tuebingen, Oct. 7, 2004
Background
 Valid measures of withdrawal are needed for
research and treatment
 Many scales are available…
 …but no comparison of their performance
 Which scale to choose?
 Aim: to compare the validity of 3 withdrawal
scales
Minnesota Withdr. Form (MWF)
 1986, 8 items:
 Depressed mood (sad)
 Insomnia
 Irritable, frustrated, angry
 Anxious (nervous)
 Difficulty concentrating
 Restless (impatient)
 Increased appetite, weight gain
 Desire or Craving to smoke
 + Total score MWF
Wisconsin Withdr. Scale (WWS)
 1999
 28 items, 7 subscales:
 Anger
 Anxiety
 Concentration
 Craving
 Hunger
 Sadness
 Sleep
 + Total score WWS
Cigarette Withdr. Scale (CWS-21)
 2003
 21 items, 6 subscales:
 Depression-Anxiety
 Craving
 Irritability-Impatience
 Appetite-Weight Gain
 Insomnia
 Difficulty Concentrating
 + Total score CWS-21
Methods
 Internet survey (in English) on STOP-TABAC.CH
 1st follow-up after 14 days
 2nd follow-up after 42 days
 Content validity: DSM-IV and ICD-10
 Factor structure: robust in bootstrap resampling?
 Reliability:
- Cronbach’s alpha
- test-retest (0-14 days) (excluding recent quitters)
Tests of predictive validity
 Hypotheses:
 In recent ex-smokers (have quit for <31 days):
baseline withdr. scores would predict relapse
- after 14 days (n = 324)
- after 42 days (n = 316)
 In baseline smokers who quit at 14-day retest:
change scores between days 0-14 would predict
relapse at day 42 (n = 34)
Tests of construct validity
 In 178 recent ex-smokers (quit <1 month) still
abstinent at day 14, withdrawal would decrease
between days 0-14
 In 27 smokers who quit between days 0 and 14,
withdrawal ratings would increase between days
0-14
 In 30 ex-smokers who relapsed at retest,
withdrawal would decrease between days 0-14
Results: participation
 N = 4644,
67% women,
 Current smokers
 Former smokers
 Never smokers
age = 40
44% (median 20 cig./day)
49% (median 60 days quit)
7% (data not reported here)
 USA=50%, Canada=10%, UK=10%, other=30%
 1st follow-up after 14 days : n = 1309 (28%)
 2nd follow-up after 42 days: n = 1431 (31%)
DSM-IV: nicotine withdrawal
Craving not included !
 Dysphoric or depressed mood
 Irritability, frustration or anger
 Difficulty concentrating, impaired performance
on tasks requiring vigilance
 Increased appetite or weight gain
 Insomnia
 Anxiety
 Restlessness, impatience
 Decreased heart rate
Results: content validity
 All 3 scales covered DSM-IV and ICD-10 criteria
of dependence, but…
 No scale covered decreased heart rate (DSM-IV)
 No scale covered cough, mouth ulcers (ICD-10)
 Wisconsin W. Scale did not cover weight gain
Factor analysis, reliability
 Factor analysis (MAP test, parallel analysis):
- 6 factors in WWS, instead of expected 7 factors,
Sadness + Anxiety items loaded on same factor
- CWS: 6 factors, as expected
- MWF: 1 factor
 Cronbach's alpha (0.76 to 0.93) were high for all
scales +subscales (redundancy in 5-item scales?)
 Test-retest coefficients:
- range 0.66-0.86 for CWS and WWS,
- low for some MWF items (range 0.52-0.80)
Predictive validity: baseline scores
 In 324 recent ex-smokers, only craving predicted
relapse at 14-day follow-up.
 No scale or subscale predicted relapse at 42 days
 Area under ROC curve = an accepted quantitative
measure of the accuracy of a test




Relapse day 14,
CWS craving:
WWS craving:
MWF craving:
AUC of ROC (95% CI):
0.63 (0.55-0.71)
0.58 (0.51-0.66)
0.64 (0.56-0.73)
Predictive validity: change scores
 In 34 smokers who had quit smoking by day 14,
an increase in withdrawal between days 0-14
predicted relapse at day 42:
Area under ROC
curve (95% CI):
 Craving (MWF)
0.76 (0.56-0.97)
 Depressed Mood (MWF)
0.72 (0.52-0.91)
 Total score WWS
 Craving (WWS)
 Diff. concentrating (WWS)
0.76 (0.58-0.94)
0.74 (0.57-0.91)
0.74 (0.57-0.91)
Prediction of relapse at day 42 by CHANGE between
days 0-14 in 34 baseline smokers who quit at day 14
1.00
.75
ROC curve
.50
Reference Line
W W S-Craving, Change
.25
baseline-retest
MW F-Craving, Change
0.00
baseline-retest
0.00
.25
1 - Specificity
.50
.75
1.00
Change between days 0-14 in 178 recent quitters
(had quit <1 month before baseline)
3
2.5
2
Baseline
Day 14
1.5
1
0.5
0
CWS-total WWS-total MWF-total
T stat from
paired-samples t-test
CWS t = 6.7
WWS t = 8.1
MWF t = 7.8
All p<.001
2.5
2.0
Minnesota Total
CRAVING
1.5
APPETITE
RESTLESS
1.0
CONCENTR
ANXIOUS
.5
IRRITABLE
INSOMNIA
0.0
DEPRESSED
0
30
60
90
120 150 180 210 240 270 300 330 360
Days of abstinence
Construct validity
 Hypothesis: withdrawal would increase postcessation: not verified, except for appetite
 Unexpected results, probably because of data
collection procedure
Conclusions
 No scale showed a decisive advantage over the others
 MWF: brief
 Single items measures in MWF: lower test-retest, but
good performance in construct validity tests
 More sophisticated tests might show that multi-item
scales do better
 Craving: performed best, but not in DSM-IV
 Further comparisons needed with
- Shiffman-Jarvik Scale
- Smoker’s Complaint Scale
- Mood and Physical Symptoms Scale (MPSS)
Acknowledgements
 No external funding
 Vincent Baujard, from HON foundation (www.hon.ch),
developed the software for data collection