Electronic Nicotine Vaping Outcomes Scale (ENVO)

Abstract

The Electronic Nicotine Vaping Outcomes Scale (ENVO) is a psychometrically validated, 32-item self-report questionnaire designed to assess cognitive outcome expectancies associated with the use of Electronic Nicotine Delivery Systems (ENDS) among emerging adults. Originally developed and standardized by Harrell et al. (2023), the ENVO addresses critical psychometric and conceptual limitations observed in legacy tobacco instruments, which were largely adapted from combustible cigarette paradigms and failed to capture modern technological, sensory, and sociocultural nuances unique to contemporary vaping devices. Beginning with an initial reservoir of 150 candidate items derived from empirical literature reviews and qualitative focus groups with diverse collegiate populations, the item pool was iteratively refined through a formal Delphi expert consensus procedure to 51 items, and subsequently distilled via exploratory and confirmatory factor analyses coupled with Item Response Theory (IRT) modeling.

The resulting instrument measures five robust, latent dimensions of vaping expectancies: Positive Reinforcement (8 items), Negative Consequences (10 items), Negative Affect Reduction (5 items), Weight Control (5 items), and Addiction (4 items). Evaluated across a racially, ethnically, and institutionally diverse sample of young adults recruited from community colleges, four-year universities, and a Historically Black College or University (HBCU) in the United States, the ENVO demonstrates exceptional psychometric properties. Internal consistency reliability across subscales is exemplary, with Cronbach’s alpha coefficients ranging from .87 to .95. Confirmatory factor analyses established excellent structural fit (CFI = 0.95, TLI = 0.94, RMSEA = 0.05), accompanied by rigorous demonstration of configural, metric, and scalar measurement invariance across biological sex, racial identities, and smoking/vaping status. Furthermore, the scale demonstrates pronounced convergent, divergent, and incremental validity, predicting prospective vaping susceptibility and lifetime usage trajectories beyond traditional demographic and environmental covariates.

Keywords

Electronic Nicotine Vaping Outcomes Scale, ENVO, Outcome Expectancies, Electronic Cigarettes, ENDS, Positive Reinforcement, Negative Consequences, Negative Affect Reduction, Weight Control, Addiction Expectancies, Psychometrics, Item Response Theory, Young Adults, Substance Use Assessment

Authors

The ENVO scale was constructed, psychometrically validated, and published through a multi-institutional collaboration comprising behavioral scientists, psychometricians, and public health epidemiologists:

• Paul T. Harrell, Ph.D. — Department of Pediatrics, Division of Community Health & Research, Eastern Virginia Medical School (EVMS), Norfolk, Virginia, United States. Correspondence: Division of Community Health & Research, P.O. Box 1980, Norfolk, VA 23501-1980. Email: [email protected].
• Thomas H. Brandon, Ph.D. — Department of Health Outcomes and Behavior, Moffitt Cancer Center, Tampa, Florida, United States; Department of Psychology and Department of Oncologic Sciences, University of South Florida, Tampa, Florida, United States.
• Stephen E. Stark, Ph.D. — Department of Psychology, University of South Florida, Tampa, Florida, United States.
• Vani N. Simmons, Ph.D. — Department of Health Outcomes and Behavior, Moffitt Cancer Center, Tampa, Florida, United States; Department of Oncologic Sciences, University of South Florida, Tampa, Florida, United States.
• Tracey E. Barnett, Ph.D. — Department of Biostatistics and Epidemiology, School of Public Health, University of North Texas Health Science Center, Fort Worth, Texas, United States. ORCID: 0000-0002-2932-1540.
• Gwendolyn P. Quinn, Ph.D. — Department of Obstetrics & Gynecology, Department of Population Health, Grossman School of Medicine, New York University, New York, New York, United States.
• Seokjoon Chun, M.A. — Department of Psychology, University of South Florida, Tampa, Florida, United States.

Purpose

The primary clinical and epidemiological objective of the Electronic Nicotine Vaping Outcomes Scale (ENVO) is to provide an empirically grounded, psychometrically sound, and culturally unbiased measurement instrument to evaluate cognitive outcome expectancies regarding electronic nicotine delivery systems among young adults aged 18 to 29 years. The transition into emerging adulthood represents a critical developmental epoch marked by heightened vulnerability to substance initiation, experimentation, and escalation into physiological dependence. Over the past decade, technological transformations in ENDS—such as high-concentration nicotine salt formulations, pod-based and disposable delivery systems, customizable voltages, and extensive aromatic flavor profiles—have fundamentally decoupled vaping from traditional combustible tobacco smoking.

Prior to the construction of the ENVO, behavioral researchers and clinical trialists relied predominantly on adapted versions of combustible cigarette measures, such as the Smoking Consequences Questionnaire (SCQ) and its short forms (SCQ-A). While historically invaluable, these adapted legacy instruments suffered from pronounced construct underrepresentation. They failed to encompass critical behavioral and sensory phenomena idiosyncratic to ENDS, including: the sensory experience of varied characterizing flavors (e.g., fruit, menthol, dessert confectionery); the physical sensations associated with modern aerosol inhalation (“throat hit”); recreational performance aspects such as performing “cloud tricks”; novel social perceptions (e.g., looking ridiculous vs. socially appealing); and specific fears regarding unknown long-term pulmonary, cardiovascular, and toxicological risks unique to aerosolized constituents.

From an applied perspective, the ENVO fills a critical void across preventive, diagnostic, and therapeutic domains:

• Etiological & Epidemiological Research: It enables researchers to quantify how specific cognitive outcome beliefs precede, mediate, and maintain vaping initiation, progression to daily dependence, and concurrent dual use with combustible tobacco products.
• Targeted Prevention & Communication Campaigns: Public health communication specialists can identify which expectancies drive susceptibility within vulnerable demographics (e.g., high positive reinforcement versus low perceived negative health consequences), allowing for the design of persuasive, counter-marketing messages tailored to debunk inaccurate positive beliefs or enhance risk literacy.
• Cognitive-Behavioral Interventions: In clinical smoking and vaping cessation protocols, the ENVO provides therapists with an assessment inventory to pinpoint cognitive distortions. For instance, individuals exhibiting elevated Negative Affect Reduction or Weight Control expectancies can be guided toward non-pharmacological affect regulation training, distress tolerance protocols, and healthy nutritional strategies to preempt relapse.
• Measurement Equity: The instrument was specifically engineered and validated across structurally marginalized and historically underrepresented student populations, ensuring that diagnostic cutoffs and psychometric profiles remain reliable and valid across diverse racial and socioeconomic strata without measurement bias.

Psychological Construct

The underlying construct assessed by the ENVO is electronic nicotine vaping outcome expectancies. In cognitive and behavioral psychology, an outcome expectancy represents an anticipatory cognitive schema regarding the probability and qualitative nature of consequences that will ensue as a direct result of engaging in a specific behavioral sequence. Rather than capturing simple factual knowledge, outcome expectancies capture subjective, contingent beliefs (“If I vape, then X will occur”) that serve as primary proximate drivers of behavioral motivation, decision-making, and behavioral reinforcement. The ENVO operationalizes this construct as a multidimensional architecture comprising five distinct factors:

1. Positive Reinforcement (PR)

This subscale comprises 8 items that assess the anticipation of direct appetitive, sensory, and recreational rewards derived from the pharmacological and tactile act of vaping. Unlike legacy smoking scales that focused primarily on generic satisfaction or taste, the ENVO PR dimension captures the multifaceted sensory-motor appeal of modern devices. This includes palatable flavor appreciation (e.g., sweetness, variety of fruit formulations), tactile oral sensations (aerosol temperature, “throat hit”, sensation on lips and tongue), recreational play (performing vapor cloud tricks), and the acute pharmacological rush or central nervous system “buzz” elicited by rapid pulmonary absorption of nicotine salts.

2. Negative Consequences (NC)

Encompassing 10 items, the Negative Consequences factor measures subjective beliefs regarding the adverse physical, somatic, health-related, and interpersonal outcomes resulting from ENDS use. The dimension reflects contemporary public awareness and epistemic uncertainty regarding vaping safety. It gauges expectancies of chronic organ-specific pathology (e.g., cardiovascular disease, pulmonary malignancy), somatic vulnerability (“The more I vape, the more I risk my health”), apprehension regarding undefined long-term toxicological damage (“serious health problems that are not yet known”), as well as social-evaluative detriments, such as looking foolish or offending bystanders and parents (“People get upset if you vape around their children”).

3. Negative Affect Reduction (NAR)

Comprising 5 items, this subscale captures the expectation of negative reinforcement—specifically, the belief that aerosol inhalation will alleviate, attenuate, or soothe aversive emotional states. Items quantify anticipated relief across distinct negative emotional modalities, including generalized anxiety, acute worry, psychological tension, anger, irritability, and depressive symptomatology. Elevated scores reflect a robust cognitive reliance on vaping as an external coping and emotion-regulation mechanism.

4. Weight Control (WC)

This 5-item dimension assesses beliefs that electronic nicotine vaping functions as an efficacious instrument for metabolic modulation, appetite suppression, and dietary restraint. Grounded in behavioral pharmacology, nicotine exhibits known anorectic properties through central hypothalamic signaling. The ENVO WC items explicitly measure expectancies that vaping curbs subjective appetite, controls body weight, prevents postprandial overeating, and enables users to actively skip or replace dietary intake with aerosol inhalation.

5. Addiction (AD)

Consisting of 4 items, the Addiction dimension evaluates subjective expectancies of neurobiological and psychological dependence. It measures the anticipatory awareness that cessation or prolonged involuntary deprivation from vaping will trigger distressing somatic withdrawal, cognitive disruptions, and intolerable affective dysregulation. Items explicitly evaluate expected loss of subjective equilibrium (“I don’t feel like myself if I go too long without vaping”), acute concentration deficits upon cessation, generalized malaise, and the escalation of unmanageable, intrusive cravings following several hours of abstinence.

Theoretical Framework

The conceptual architecture of the ENVO scale is anchored at the convergence of Social Cognitive Theory, Cognitive Expectancy Models of Substance Use, and the Behavioral Pharmacology of Nicotine.

Social Cognitive Theory & Triadic Reciprocal Determinism

Formulated by Albert Bandura (1986), Social Cognitive Theory posits that human behavioral adaptation is governed by triadic reciprocal causation, wherein cognitive personal factors, environmental events, and behavioral patterns continuously interact. Within this paradigm, outcome expectancies function as foundational cognitive determinants of agency. Individuals do not merely respond to external environmental stimuli; rather, they process, symbolize, and evaluate anticipated outcomes of alternative actions. According to Bandura, when anticipated positive consequences outweigh anticipated negative consequences, the subjective valuation of the behavior rises, drastically escalating initiation likelihood, behavioral frequency, and resistance to extinction.

Expectancy Theory of Addictive Behaviors

In the domain of addiction science, the cognitive expectancy model was pioneered through the landmark empirical work of Mark Goldman, Thomas Brandon, and colleagues (e.g., Brandon & Baker, 1991; Goldman et al., 1987). Expectancy theory contends that repeated biological exposure to a substance, paired with social observation, vicarious learning, and cultural marketing, establishes deeply encoded semantic memory networks. These associative networks store mental representations regarding the contingent effects of substance administration.

Once formed, these outcome expectancies operate as cognitive filters that mediate the pathway between distal risk factors (e.g., genetic vulnerability, sensation seeking, peer tobacco use) and proximal behavioral execution (initiation, titration, relapse). The ENVO operationalizes this cognitive model by bifurcating outcomes along primary operant conditioning pathways:

• Positive Reinforcement Paradigms: Driven by dopaminergic transmission along the mesocorticolimbic pathway, positive reinforcement expectancies conceptualize drug consumption as an active generator of reward, euphoria, sensory pleasure, and social identity.
• Negative Reinforcement Paradigms: Anchored in opponent-process and allostatic theories of addiction (e.g., Koob & Le Moal), negative reinforcement expectancies conceptualize substance intake as an instrument to alleviate somatic discomfort, emotional distress, or the aversive symptoms of nicotine withdrawal.

Technological & Pharmacological Evolution of ENDS

A crucial theoretical premise driving the creation of the ENVO was the recognition that modern ENDS are pharmacologically and socially disparate from 20th-century combustible cigarettes. The introduction of benzoic acid and other organic acid nicotine formulations reduced aerosol pH, enabling high concentrations of unprotonated nicotine to be inhaled with minimal upper airway harshness. This chemical optimization facilitates rapid brain arterial absorption rates that match or exceed combustible cigarettes, producing sharp subjective “rushes” while simultaneously accommodating complex flavor chemistry. The ENVO explicitly incorporates these unique pharmacological kinetics and sensory features into its underlying theoretical construct.

Validity

The psychometric validation of the ENVO by Harrell et al. (2023) entailed comprehensive assessments of convergent, divergent, incremental, and structural validity across culturally diverse collegiate populations.

Convergent and Divergent Validity

Convergent and divergent validity was established through correlation analyses examining relationships between the five ENVO subscales and established behavioral benchmarks: vaping susceptibility (among non-users) and lifetime vaping history (across the full sample).

• Vaping Susceptibility: Susceptibility to future ENDS initiation was robustly and positively correlated with expectancies of Positive Reinforcement ($r = .44, p < .001$) and Negative Affect Reduction ($r = .24, p < .001$). Modest positive associations emerged with Weight Control ($r = .09, p < .001$) and Addiction ($r = .05, p < .05$). In strong support of divergent validity, susceptibility was significantly and negatively correlated with the Negative Consequences subscale ($r = -.25, p < .001$), demonstrating that young adults who anticipate high health and social penalties exhibit lower cognitive openness to vaping initiation.
• Lifetime Vaping History: An identical, robust pattern was observed regarding lifetime usage trajectories. Lifetime vaping demonstrated strong positive correlations with Positive Reinforcement ($r = .49, p < .001$) and Negative Affect Reduction ($r = .26, p < .001$), modest correlations with Addiction ($r = .08, p < .001$) and Weight Control ($r = .07, p < .001$), and a significant inverse association with Negative Consequences ($r = -.18, p < .001$).

Incremental Validity

To confirm that the ENVO accounts for unique behavioral variance beyond standard epidemiological risk indicators, hierarchical linear regression analyses were conducted. After rigorously entering and controlling for sociodemographic factors (age, biological sex, race/ethnicity), direct commercial exposure to vaping marketing, and social influence vectors (peer and familial vaping prevalence), the five ENVO factor scores accounted for significant incremental variance in lifetime vaping frequency. Positive Reinforcement consistently emerged as the most potent statistical driver of usage behaviors, confirming that cognitive outcome schemas contribute unique explanatory power over and above environmental and social peer modeling.

Item Response Theory (IRT) Characteristics

To evaluate the latent measurement properties of the individual items, Harrell et al. fitted Samejima’s Graded Response Model (GRM) within an IRT framework:

• Item Discrimination ($a$ parameters): Discrimination estimates ranged from $a = 1.26$ to $a = 3.18$. In psychometric conventions, values exceeding 1.70 indicate very high discrimination. The items strongly differentiate between individuals with moderate versus high levels of underlying latent outcome expectancies ($ heta$).
• Item Difficulty/Thresholds ($b$ parameters): Across the five subscales, location parameters ranged from $b = 0.72$ to $b = 2.47$. This distribution demonstrates that the items comprehensively measure the continuum of outcome beliefs, spanning from normative expectations to highly elevated, clinically severe dependency expectancies without exhibiting premature floor or ceiling anomalies.

Reliability

The ENVO demonstrates outstanding reliability across all five subscales, establishing high measurement precision across diverse academic environments and demographic cohorts.

Internal Consistency

Internal consistency estimates were computed using Cronbach’s alpha ($lpha$) within both calibration and validation split-half samples. Every subscale comfortably exceeded the conventional psychometric threshold of $lpha ge .80$ for group research and $lpha ge .90$ for clinical diagnostics:

• Negative Affect Reduction: $lpha = .95$ (5 items) — Reflects near-perfect internal homogeneity regarding emotional self-medication beliefs.
• Negative Consequences: $lpha = .94$ (10 items) — High precision across broad toxicological, medical, and social hazard evaluations.
• Positive Reinforcement: $lpha = .92$ (8 items) — Robust consistency across sensory, flavor, and physiological reward expectations.
• Weight Control: $lpha = .92$ (5 items) — Cohesive measurement of appetite suppression and dietary avoidance expectancies.
• Addiction: $lpha = .87$ (4 items) — Substantial reliability for assessing anticipation of physiological dependence and withdrawal distress.

Standard Error of Measurement and Score Precision

Item Information Curves (IIC) and Total Test Information (TIF) functions derived from the IRT Graded Response Models revealed that the ENVO provides maximal measurement precision (minimal standard errors of measurement, $SEM$) within the standard score range of $ heta = -1.0$ to $ heta = +2.5$. This indicates that the scale is acutely calibrated for detecting subtle shifts in cognitive expectancies among individuals progressing from non-susceptible experimental contemplation to entrenched chemical dependence.

Factor Analysis

The structural dimensionality of the ENVO was evaluated using a rigorous split-half cross-validation methodology, combining exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and multigroup measurement invariance testing.

Exploratory Factor Analysis (EFA)

The initial 51-item pool derived from Delphi panel refinement was administered to an exploratory development subsample ($n = 753$). Multiple empirical criteria converged to identify the latent dimensionality:

• The Kaiser-Guttman criterion (eigenvalues > 1.0);
• Cattell’s scree test displaying an inflection break point after five factors;
• Horn’s Parallel Analysis utilizing 500 Monte Carlo simulated random data matrices;
• Velicer’s Minimum Average Partial (MAP) test (both original and revised versions).

All empirical extraction tests converged on a definitive 5-factor solution. During oblique rotation (promax/geomin), item reduction criteria were strictly enforced: items displaying cross-loadings greater than .20 on secondary factors were eliminated (5 items removed), and items exhibiting semantic redundancy alongside lower primary loadings were discarded (14 items removed). The final 32-item architecture emerged with remarkably robust primary factor loadings spanning from $lambda = .60$ to $lambda = 1.00$, with negligible off-target cross-loadings.

Confirmatory Factor Analysis (CFA)

The derived 5-factor model was subsequently cross-validated on an independent validation subsample ($n = 754$) using robust diagonally weighted least squares (WLSMV) estimation to account for ordinal categorical distributions. The 5-factor correlated model displayed exemplary goodness-of-fit indices:

• Comparative Fit Index (CFI): $0.95$ (exceeding the standard $ge .95$ benchmark for excellent fit);
• Tucker-Lewis Index (TLI): $0.94$ (comfortably above the recommended $ge .90$ criterion);
• Root Mean Square Error of Approximation (RMSEA): $0.05$ (90% Confidence Interval: $[0.046, 0.054]$), well below the stringent $le .06$ threshold.

Measurement Invariance

A distinctive scientific strength of the ENVO validation is its extensive evaluation of multigroup measurement invariance across diverse demographic and behavioral populations. Through sequential nested model comparisons (evaluating $Delta ext{CFI} le .010$ and $Delta ext{RMSEA} le .015$), the ENVO demonstrated full configural, metric (weak), and scalar (strong) invariance across:

1. Biological Sex: Invariant across male and female respondents.
2. Racial Identification: Invariant across multi-group racial comparisons (White non-Hispanic vs. racial/ethnic minority cohorts, and Black/African American vs. other racial backgrounds).
3. Tobacco & Vaping Status: Invariant across combustible tobacco users versus non-users, lifetime vaping experiencers versus never-vapers, and active current vapers versus abstinent individuals.

Demonstrating scalar invariance is vital: it guarantees that observed differences in ENVO subscale means across biological sexes, racial groups, or smoking categories reflect genuine psychological differences in latent outcome beliefs, rather than differential item functioning (DIF) or psychometric measurement artifact.

Instrument / Measurement Tool

Below is the structured technical profile for the administration and scoring of the scale:

• Test Type: Original multidimensional psychometric self-report inventory / rating scale.
• Administration Format: Self-administered paper-and-pencil questionnaire or computerized web/mobile assessment.
• Item Count: 32 items divided across 5 subscales:
  • Positive Reinforcement: 8 items (Items 1–8)
  • Negative Consequences: 10 items (Items 9–18)
  • Weight Control: 5 items (Items 19–23)
  • Addiction: 4 items (Items 24–27)
  • Negative Affect Reduction: 5 items (Items 28–32)
• Response Scale: Standardized 5-point Likert-type scale with the following anchors:
  • 1 = Strongly disagree
  • 2 = Disagree
  • 3 = Neither agree nor disagree (Neutral)
  • 4 = Agree
  • 5 = Strongly agree
• Target Population: Emerging adults and adults (aged 18 to 29 years; general collegiate, vocational, and non-collegiate adult populations).
• Estimated Completion Time: 5 to 8 minutes.
• Scoring Procedures:
  • All 32 items are framed in a direct positive direction relative to their construct; there are no reverse-scored items.
  • Subscale scores are calculated by computing the arithmetic mean (average) or the raw sum of items within each subscale domain. Mean scoring (ranging from 1.00 to 5.00 per subscale) is recommended to allow direct comparative interpretation across dimensions of differing item lengths.
  • Higher mean scores on Positive Reinforcement, Negative Affect Reduction, Weight Control, and Addiction reflect stronger expectations of reward, affect relief, metabolic control, or dependence vulnerability, respectively.
  • Higher scores on Negative Consequences reflect a greater perception of toxicological, physical, and social hazards associated with ENDS.

Permissions & Fee and Test Year

The Electronic Nicotine Vaping Outcomes Scale (ENVO) was formally established and published in 2023 by Paul T. Harrell and colleagues in the journal Drug and Alcohol Dependence. In accordance with open-science practices and standard academic psychometric dissemination, the instrument is available free of charge for non-commercial, academic, clinical, and scholarly research purposes. Commercial utilization, proprietary software integration, or fee-based clinical platforms require formal licensing permissions from the primary corresponding author and copyright holders. Academic investigators conducting empirical studies are encouraged to cite the foundational publication:

Direct inquiries regarding scale utilization, data sharing, or institutional translations should be directed to the corresponding developer: Dr. Paul T. Harrell, Department of Pediatrics, Division of Community Health & Research, Eastern Virginia Medical School, Norfolk, VA, United States (Email: [email protected]).

References

The following scientific literature provides foundational theoretical, methodological, and empirical backing for the ENVO scale:

• Bandura, A. (1986). Social foundations of thought and action: A social cognitive theory. Prentice-Hall, Inc.
• Brandon, T. H., & Baker, T. B. (1991). The Smoking Consequences Questionnaire: The subjective expected utility of smoking in college students. Psychological Assessment: A Journal of Consulting and Clinical Psychology, 3(3), 484–491. https://doi.org/10.1037/1040-3590.3.3.484
• Goldman, M. S., Brown, S. A., & Christiansen, B. A. (1987). Expectancy theory: Thinking about drinking. In H. T. Blane & K. E. Leonard (Eds.), Psychological theories of drinking and alcoholism (pp. 181–226). The Guilford Press.
• Harrell, P. T., Brandon, T. H., Stark, S. E., Simmons, V. N., Barnett, T. E., Quinn, G. P., & Chun, S. (2023). Measuring vaping-related expectancies in young adults: Psychometric evaluation of the electronic nicotine vaping outcomes (ENVO) scale. Drug and Alcohol Dependence, 246, 1–9, Article 109861. https://doi.org/10.1016/j.drugalcdep.2023.109861
• Samejima, F. (1969). Estimation of latent ability using a response pattern of graded scores. Psychometrika Monograph Supplement, 34(No. 4, Pt. 2), 1–100. https://doi.org/10.1007/BF03372160

13. Items of the Scale (Questionnaire)