Psychometric Validity of the Minnesota Tobacco Withdrawal Scale in Smokers Attempting to Quit: Longitudinal Invariance across Smokers and Abstainers

Tobacco withdrawal symptoms vary during smoking cessation increasing relapse risk; therefore, a longitudinal invariant measure seems necessary to validly assess withdrawal changes. This study aimed to examine the psychometric properties of the 7-item Minnesota Tobacco Withdrawal Scale (MTWS) during cessation, and to analyze longitudinal invariance across smokers and abstainers. We conducted a longitudinal study with 309 Spanish smokers (56.2 +/- 9.9 years; 52.4% women). We assessed withdrawal at three occasions: pre-treatment (T1), week-12 (T2), and week-24 (T3). Reliability, validity, and invariance analyses were performed. MTWS reliability remained adequate over time (omega(T1) = 0.78; omega(T2) = 0.68; omega(T3) = 0.80) in both smokers and abstainers, with satisfactory temporal stability (ICC = 0.73). MTWS correlations with anxiety, depression, and nicotine dependence (r(s) > 0.3) supported convergent and concurrent validity. MTWS showed no correlation with craving at T2 (r(s) < 0.24), suggesting discriminant validity. Unifactorial structure proved partial scalar invariance across time (chi(2) = 246.009; CFI = 0.91; IFI = 0.91; SRMR = 0.09), yet longitudinal invariance between abstainers and smokers was not supported. Across groups, partial scalar invariance was only achieved at T2. Noninvariance at T3 was mainly due to item irritability (d(MACS) = 0.93). The MTWS is reliable and valid measure to assess withdrawal changes during cessation. Long-term MTWS comparisons between smokers and abstainers should be taken with caution since different withdrawal patterns may exist.

Automated summary

This study examined the psychometric properties of the Minnesota Tobacco Withdrawal Scale (MTWS) during smoking cessation and analyzed the longitudinal invariance between smokers and abstainers. The results showed that the MTWS is a reliable and valid measure to assess withdrawal changes during cessation. However, caution should be taken when comparing long-term MTWS scores between smokers and abstainers due to potential differences in withdrawal patterns.