Data from NPDS, a national surveillance system, indicate that approximately one-fifth of e-cigarette-related burn cases reported to PCCs were not referred to or did not arrive at HCFs. This information is complementary to the findings from previous studies on e-cigarette-related burn injury cases presented to EDs (4, 7) and is helpful in understanding the overall burden of e-cigarette-related burn injuries.
Previous studies estimate that more than 1,000 e-cigarette explosion and burn injuries occur in the U.S. per year (4, 7). Only 69 e-cigarette-related burn cases were documented in NPDS from 2010 to 2019. This small number of burn cases in NPDS may reflect a substantial underreporting commonly suffered by surveillance systems relying on voluntary reporting. Since PCCs’ primary goal is to help individuals manage poisoning exposures, many burn cases that required immediate medical attention probably bypassed calling PCCs for help and presented to EDs directly.
We observed the largest number of e-cigarette-related burn cases in 2016 followed by a decline in 2017, a similar observation as noted by Rossheim et al. in their study on e-cigarette-related burn and explosion injuries presenting to EDs (7). The decline in the number of burn cases from 2016 to 2017 we observed was more pronounced than that reported by Rosseheim et al. This decline coincided with the following events occurring around the time: (1) FDA provided an online education program entitled “Tips to Help Avoid “Vape” Battery Explosions” (16); (2) the U.S. Fire Department published a report of e-cigarette-related fires and explosions in the U.S. and provided information on appropriate use of e-cigarettes (17); and (3) several case series reports of explosion injuries from e-cigarettes in the U.S. were published to alert the public about potential dangers of e-cigarette explosions, including two reports by FDA (5, 6, 18). As voluntary reports to PCCs involving e-cigarette-related burns can be affected by several factors, such as media coverage and awareness level of free services provided by PCCs, it is unclear whether media and published reports influenced individuals’ awareness of e-cigarette-related burns, leading to reports to PCCs. Specific reasons for the decline in the number of cases from 2016 to 2017 are difficult to identify with certainty. Given the small number of cases and limitations of NPDS as a passive surveillance system, caution is warranted when interpreting the findings of this study.
One of the unique features of PCCs is their case narratives documenting details on each case, including the circumstances of exposures, the development and progress of the case, treatment and management, and outcome. From the review of case narratives for all 69 burn cases, we noted that six mentioned leaking e-liquids. To our knowledge, this is the first study to suggest that leaky e-cigarettes may be involved in burn injuries. As the landscape of e-cigarettes is evolving rapidly, active surveillance of NPDS, NEISS, social media data, and other data is important for identifying health risks of these products and informing efforts to prevent harm associated with emerging tobacco products (19-21). FDA has taken steps to address some safety issues associated with e-cigarettes and e-liquids. In November 2019, FDA issued a guidance about its compliance policy for limited safety modifications to certain marketed tobacco products, including battery-operated tobacco products to address battery injury concerns in order to better protect consumers(22).
One of the major limitations of this study is underreporting, as discussed previously. In addition, self-reported information on burn characteristics is subject to reporting bias, particularly for the burn cases reported by individuals from their own residences, which represent nearly one-third of the burn cases. However, a unique feature of NPDS is the use of follow-up contacts to verify and update information initially reported to PCCs to ensure the accuracy of the information in addition to monitoring case progress, collecting additional information, and determining the medical outcome of the cases (12). Finally, lack of a standard format for case narratives may have resulted in somewhat inconsistent case narrative findings between the two reviewers, particularly for information on type of burn. Unlike the information on explosion and body part burned, type of burn was not directly stated in the case narratives and details sometimes were buried in the progress notes (i.e., follow-up notes) rather than in the initial note. The wide variation in case narratives could be the primary reason for the relatively low inter-reviewer reliability for some of the case narrative findings, such as type of burn. However, the third reviewer reviewed the case narratives to reconcile the discrepancies and provided final coding for the data analysis.
This study analyzed data from a national surveillance system to describe the frequency and characteristics of e-cigarette-related burn cases as well as the proportion of those cases that did not present to health care facilities. The number of burn cases documented in NPDS represents a small proportion of total e-cigarette-related burn cases, but it can serve as a complementary data source to other traditional injury surveillance systems, such as NEISS and FDA Safety Reporting Portal (www.safetyreporting.hhs.gov). Findings from case narratives provide additional contextual information that may inform tobacco product labeling, the development of tobacco product standards, and health communication and education programs aimed at preventing e-cigarette-related burns.