Examining the factor structure of the Clinical Opiate Withdrawal Scale: A secondary data analysis from the National Drug Abuse Treatment Clinical Trials Network (CTN) 0003.

Abstract

BACKGROUND:

The Clinical Opiate Withdrawal Scale (COWS) is used to assess withdrawal in clinical trials and practice. The aims of this study were to examine the inter-item correlations and factor structure of the COWS in opioid-dependent men and women.

METHODS:

This is a secondary data analysis of the National Drug Abuse Treatment Clinical Trials Network 0003, a randomized clinical trial that compared buprenorphine/naloxone tapering strategies. The trial included 11 sites in 10 US cities. Participants were opioid-dependent individuals (n=516) that had data on the COWS. The COWS at study baseline was analyzed in this study.

RESULTS:

Inter-item correlations showed weak to moderate relationships among the items. A 1-factor model did not fit the data for men (comparative fit index (CFI)=.801, root mean square error of approximation (RMSEA)=.073, weighted root mean square residual (WRMR)=1.132) or women (CFI=.694, RMSEA=.071, WRMR=.933), where resting pulse rate was not related to withdrawal for men, and yawning and gooseflesh skin was not related to withdrawal for women. A reduced model comprised of only the 8 items that were significantly related to the construct of withdrawal in both men and women, and an exploratory 2-factor model, were also assessed but not retained due to inconsistencies across gender.

CONCLUSIONS:

When traditional psychometric models are applied to the COWS, it appears that the scale may not relate to a single underlying construct of withdrawal. Further research testing the hypothesized factor structure in other opioid-dependent samples is needed.

• Authors: Celestina Barbosa-Leiker, Sterling McPherson, Mary Rose Mamey, G Leonard Burns, Matthew E Layton, John Roll, Walter Ling
• Journal: Drug and alcohol dependence (Drug Alcohol Depend) Vol. 152 Pg. 218-23 (Jul 01 2015) ISSN: 1879-0046 [Electronic] Ireland
• PMID: 25908321 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Analgesics, Opioid
• Buprenorphine, Naloxone Drug Combination

Topics

• Analgesics, Opioid (therapeutic use)
• Buprenorphine, Naloxone Drug Combination (therapeutic use)
• Female
• Humans
• Male
• Middle Aged
• Opioid-Related Disorders (diagnosis, drug therapy)
• Psychometrics
• Randomized Controlled Trials as Topic
• Substance Withdrawal Syndrome (diagnosis, drug therapy)
• United States