Characteristics of Persons Who Report Using Only Nicotine-Containing Products Among Interviewed Patients With E-cigarette, or Vaping, Product Use–Associated Lung Injury

Illinois, August-December 2019

Isaac Ghinai, MBBS; Livia Navon, MS; Jayleen K.L. Gunn, PhD; Lindsey M. Duca, PhD; Sarah Brister, MPH; Sarah Love; Rachel Brink; Geroncio Fajardo, MD; Jona Johnson, PhD; Lori Saathoff-Huber, MPH; Brian A. King, PhD; Christopher M. Jones, PharmD, DrPH; Vikram P. Krishnasamy, MD; Jennifer E. Layden, MD, PhD

Disclosures

Morbidity and Mortality Weekly Report. 2020;69(3):84-89. 

In This Article

Abstract and Introduction

Introduction

In 2019, the United States experienced an outbreak of e-cigarette, or vaping, product use–associated lung injury (EVALI).[1] Most EVALI patients have reported using tetrahydrocannabinol (THC)-containing e-cigarette, or vaping, products obtained from informal sources,[2,3] and vitamin E acetate in these products has been closely linked with EVALI.[4,5] However, some EVALI patients report using only nicotine-containing products. This study compared demographic, product use, and clinical characteristics of EVALI patients in Illinois who reported using only nicotine-containing e-cigarette, or vaping, products with those of patients who reported using any THC-containing products. Among 121 interviewed Illinois EVALI patients, 17 (14%) reported using only nicotine-containing products, including nine (7%) patients who had no indication of any THC use, based on self-report or toxicology testing. Compared with patients who used any THC-containing products, these nine patients were significantly more likely to be older and female and were less likely to experience constitutional symptoms or to have leukocytosis on initial evaluation. Although vitamin E acetate has been strongly linked with EVALI, evidence is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC- or non-THC-containing products, in some reported EVALI cases. The contributing cause or causes of EVALI for patients reporting use of only nicotine-containing products warrants further investigation.

Medical records were requested for all suspected EVALI cases reported to the Illinois Department of Public Health (IDPH), and clinical information was abstracted using a standardized form. Cases were included in this study if the illness met the EVALI surveillance definition for a confirmed or probable case.* EVALI patients or their proxies were also asked to complete a structured questionnaire that collected information about demographics and e-cigarette, or vaping, product use. A follow-up interview was attempted with all patients who reported that they did not use THC-containing products on the initial questionnaire to confirm that they used only nicotine-containing products, and corresponding medical records were reexamined for any indication of THC use (e.g., a positive urine cannabinoid screen or report of smoking combustible marijuana to a health care provider). When available, bronchoalveolar lavage fluid specimens were sent to CDC for laboratory testing. EVALI cases reported during July 20–December 1, 2019, with a completed initial structured questionnaire were included in this analysis.

Among 195 EVALI cases reported to IDPH, 121 patients (62%) had a completed structured questionnaire. These patients were categorized into two analysis groups: those who reported using any THC-containing products and those who reported using no THC-containing products and reported using only nicotine-containing products. The group that reported no THC-containing product use was further stratified into two groups: those with no indication of any THC use after follow-up interview and reexamination of medical records and those who reported no THC-containing e-cigarette, or vaping, product use but who did have evidence of using THC (e.g., disclosed use of combustible marijuana or had a positive urine cannabinoid screen).

Demographic characteristics, use of nicotine-containing products, and clinical characteristics of patients with no indication of any THC use were compared with those who reported any THC-containing product use. To allow replication analyses by other health departments, where access to the follow-up interviews or medical records necessary to define the subgroups compared here might not be available, patients who reported using no THC-containing products (whether or not they had subsequent indication of any THC use) were also compared with those patients who reported using THC-containing products. Differences were assessed using Pearson's chi-squared test or Fisher's exact test for cells with <5 observations. The Wilcoxon rank sum test was used to compare medians. P-values <0.05 were considered statistically significant. Analyses were conducted using SAS (version 9.4; SAS Institute).

Initially, 19 (16%) of 121 interviewed Illinois EVALI patients reported using only nicotine-containing products (Figure), nine of whom participated in a follow-up interview; at that time, two patients (both aged <18 years) disclosed that they used products likely to have contained THC. Both patients completed the initial questionnaire with parents present, whereas follow-up interviews were conducted privately (with parental consent). Thus, overall, 104 patients (86%) reported using any THC-containing products, and 17 (14%) reported using only nicotine-containing products. Six of the 17 patients who reported using only nicotine-containing products also reported smoking combustible marijuana, and two other patients had positive urine cannabinoid screens and reported combustible marijuana use to their health care providers; bronchoalveolar lavage fluid from one of these patients was available for testing, and both THC and vitamin E acetate were detected in the fluid. Thus, nine of 121 patients (7%) had no indication of any THC use and constituted the analysis subgroup; three of these patients underwent urine cannabinoid screening and all were negative.

Figure.

Categorization of patients with confirmed and probable e-cigarette, or vaping, product use–associated lung injury (EVALI), by tetrahydrocannabinol (THC)-containing product use — Illinois, July–December 2019

Among 104 patients who reported using any THC-containing products, 46 (44%) were classified as having confirmed EVALI, compared with two of 17 patients (12%) who reported using only nicotine-containing products, and none of nine patients with no indication of any THC use (p = 0.01 for both) (Table 1). For the most part, these nine patients did not meet the minimum criteria for negative infectious disease testing to be classified as a confirmed case, in some instances because infection was not considered in the differential diagnosis. Compared with patients who reported using any THC-containing products, patients with no indication of any THC use were more likely to be female (78% versus 25%; p<0.01) and aged ≥45 years (33% versus 2%, p<0.01). There were no statistically significant differences in the frequency of use of nicotine-containing products, number of nicotine-containing products used, or source of the nicotine-containing products.

At initial hospital evaluation, patients with no indication of any THC use were less likely than were patients who reported using any THC-containing products to experience constitutional symptoms (56% versus 96%; p<0.01), have an initial leukocytosis (38% versus 91%; p<0.01), or to have presented to an outpatient provider or emergency department before hospitalization (25% versus 80%; p<0.05) (Table 2). There were no statistically significant differences between patients with no indication of any THC use and those who reported using any THC-containing product in initial vital signs, other initial laboratory results, admission to an intensive care unit, or severe outcome (defined as death or respiratory failure requiring endotracheal intubation and mechanical ventilation).

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