In this study, we used a nationally representative sample from 2013 through 2015 to assess ED utilization among skin cancer patients. Skin cancer-related visits shared similar presentations with previously reported overall cancer-related ED visits, but also had presentations unique to skin cancer. Specifically, compared to the 2017 study by Rivera et al. which reviewed all cancer-related ED visits1, seven of the top ten most common reasons for ED visits were shared between skin cancer-related visits and all cancer-related visits. Many of these primary diagnoses were related to age-related comorbidities, including cardiac dysrhythmias and chronic obstructive pulmonary disease, which is in line with the idea that both skin cancer and cancer in general tend to primarily affect the elderly. However, these primary diagnoses appeared to be less severe in skin cancer-related visits than all cancer-related visits as the admission percentages were lower for skin cancer-related visits for all seven diagnoses.
ED visits and inpatient admissions were more likely to occur among both males and elderly skin cancer patients. However, while patients from higher income quartiles had greater utilization of the ED, they were less likely to be admitted to the hospital as a result of their ED visit. Similarly, relative to those with Medicare, those with private insurance had higher adjusted odds of having a skin cancer-related ED visit but decreased adjusted odds of being admitted to the hospital. The discrepancy in ED visits versus admissions and poorer outcomes may either be due to an access-to-care issue in that low socioeconomic status individuals predominantly visit the ED for severe reasons or that less access to care is associated with more late-stage disease due to less access to outpatient treatments and/or poorer early detection of skin cancer. This is further supported by a 2006 study using the SEER database by Reyes-Ortiz et al. which found that older individuals covered by Medicare in lower socioeconomic areas had poorer 5-year melanoma survival than older individuals covered by Medicare in higher socioeconomic areas.3
Unique to skin cancer-related visits was the relatively high rate of skin and subcutaneous infections as well as complications of surgical procedures or medical care (4th and 8th most common primary diagnosis, respectively), which was absent in the top ten primary diagnoses for all cancers in the analysis performed by Rivera et al. Both diagnoses resulted in admission greater than 45% of the time. This was interesting in the setting of the widely reported low complication rates seen with skin cancer treatment.4 However, this observation is limited by the unknown temporality between treatment and the ED visit, as well as the lack of detail in regards to the treatment modality. Future studies are needed to better understand the connection between serious infections and skin cancer.
Notably, even though melanoma represents less than 5% of all skin cancers,5 it represented 27.58% of skin cancer-related ED visits and 51.18% of skin cancer-related inpatient admissions from the ED. Additionally, there were greater odds of admission for melanoma compared to a keratinocyte carcinoma in multivariable analysis. This is likely indicative of the higher severity of melanoma and a greater application of systemic interventions for its treatment. Irrespective of skin cancer type, we observed the rate of inpatient admissions to be much higher for patients with skin cancer compared to patients without skin cancer (45.04% versus 16.39%).
As with previous studies that utilize the NEDS database, our analysis is limited by the use of CCS codes. Since the NEDS database is only able to utilize up to 15 CCS codes, misclassification is possible if a skin cancer CCS code is not included. In addition, patients with both a melanoma and nonmelanoma skin cancer CCS code were excluded from the analysis. Both of these scenarios should only account for a minimal proportion of the skin cancer-related ED visits, thus having an insignificant impact on the conclusions of our analysis. Additionally, treatment and staging codes are not available in the NEDS database, so it is difficult to understand how ED utilization is different among various stages of skin cancer and treatment approaches. Finally, there is potential for duplicate counting to exist in the dataset as transfers between institutions that provide data to HCUP can result in 2 encounters being recorded within the NEDS database.
Despite these limitations inherent to the NEDS database, our study provides a robust, baseline evaluation of ED utilization specific to skin cancer across the United States. The large size of the NEDS database with over 30 million ED visits annually allows our results to be highly generalizable. Additionally, the use of survey procedures to account for the HCUP-NEDS sampling design limited bias and improved the validity of our results.