The CCR identified 222,087 adults with a new primary cancer diagnosis in 2009–2010. After excluding those with Stage 0 cancer (n = 21,154) and nonmelanoma skin cancer (n = 1,031), for whom data are inconsistently collected by CCR, a total of 199,872 individuals were included in the analytic sample. Of those patients (Table 1), most were white non-Hispanic (62%), women (51%), holders of private insurance (53%), married (56%), and urban residents (86%). Most were older than 50 years and had either Stage I or Stage II cancer. The most common cancer types were breast (17%), prostate (16%), lung (11%), and colon (9%; results not shown). In unadjusted comparisons, the incidence of ED use was significantly higher among those who were older, of non-Hispanic black race/ethnicity, uninsured, in the lowest SES group, widowed, or diagnosed with Stage IV cancer (Table 1).

This study extends previous research by describing ED use for more than 20 cancer types by time from diagnosis in a large, heterogeneous and population-based sample of recently diagnosed adults in California. We found that 16% of newly diagnosed individuals with cancer used the ED within 30 days of diagnosis, 35% within 6 months of diagnosis, and 44% within 1 year of diagnosis. These findings suggest that ED use by cancer patients is more than double that of the US general population and is higher than previously estimated for cancer patients.^10,24 In 2010, about 21% of the US population visited the ED, compared with 44% of cancer patients in the same time period.²⁴ Although persons with greater medical need, such as those with cancer, inevitably require more health services, new approaches are needed to explore the extent to which some of these visits by cancer patients could be prevented by providing care in other settings.

Few studies have examined ED use by cancer patients, but previous findings suggest that 1%−12% of cancer patients use the ED within 30 days of diagnosis, and 15%−25% use the ED within a year of diagnosis.^10,25,26 One study did report higher rates of ED use by cancer patients, but attributed the increased use to changes in Medicaid copayments.²⁷ The finding that ED use is higher among cancer patients than previously considered is important for several reasons. First, high rates of ED use may reflect excessive fragmentation in cancer care, or patients’ inability to access providers when acute concerns arise. Furthermore, providers and policymakers may be particularly interested in populations with high ED use because reducing potentially preventable ED use is often cited as one of the goals of care coordination and alternative health care model programs.^2,28,29

The number of newly diagnosed cancer patients with multiple ED visits is also substantial. We found 15% of recently diagnosed cancer patients had two or more ED visits within 180 days of diagnosis, compared with 8% of the general US population having two or more ED visits in all of 2010.²⁴ Among cancer patients with at least one ED visit, 44% visited more than once. Repeat visits may represent worsening health status, continued unmet health needs, or new complications that might have been prevented or treated in other health care settings. In addition, there may be opportunities to identify cancer patients at risk for multiple visits at their initial ED visit. A better understanding of the reasons for ED visits and the factors driving unmet need – such as inadequate patient education, limited access to specialty services, or failure to admit a patient to resolve a problem appropriately (eg, pain, infection) – may help to identify which visits are potentially preventable. Ultimately, failure to adequately describe the number of cancer patients that visit the ED and the number of times they visit may result in a lost opportunity for improvement in care, the patient experience and cost reduction in cancer care.

The distinction between cancer types that account for the most ED visits and cancer types with the highest cumulative incidences of ED use is informative. For instance, lung cancer patients accounted for the largest number of ED visits and over half of those with lung cancer visited the ED within 180 days of diagnosis. However, although more than 60% of individuals with pancreatic cancer visited an ED within 180 days of diagnosis; they accounted for only 5% of all ED visits by cancer patients during the same time period. This in part reflects the relative frequency of these cancers. However, prostate cancer, which has a high incidence rate, represents about 8% of all ED visits by cancer patients, yet only 17% of all prostate cancer patients visit the ED within 180 days of diagnosis.

One approach to reduce the absolute number of ED visits by cancer patients would be to target the most frequent users of the ED such as lung, breast, prostate, and colon cancer patients. These cancers are the most common in the general population, so proportionate reduction in ED visits in these groups would have a large overall impact on ED use. Alternatively, patients with cancers that have high rates of ED use could be targeted with interventions to better address their needs. Additional studies of ED use among cancer patients, including understudied cancers, are needed to determine whether care provided in the ED could be provided in alternate clinical settings. Such research can also support training of emergency department staff to manage the full range of cancer-related conditions presenting to the ED.

Another approach to identifying potentially avoidable ED visits is to explore visits that result in admission to the hospital compared with those that result in discharge from the ED. In some circumstances, visits that result in discharge home may not have been true medical emergencies, and therefore might have been preventable. It is also true that even an acute problem requiring admission may have been preventable with timely outpatient management. While we found that 45% of visits ended in discharge home, over half of cancer patients who visit the ED are admitted to the hospital. This is higher than admission rates from the ED for the U.S. population overall (11%−15%),^30–32 and even higher than the estimated rate of individuals with chronic conditions, such as diabetes (42%), who visit the ED and then are subsequently admitted to the hospital.³³

Relatively high rates of admissions may indicate that cancer patients seeking care in the ED require increased medical attention; however, it is possible that other explanations exist. For instance, ED physicians may be uncomfortable with complex cancer cases and may admit patients to be evaluated by a specialist. As such, it is possible that some of these admissions could have been appropriate for outpatient follow up. It is also possible that patients are referred to the ED for admission to the hospital. In these situations the ED visit may be entirely preventable through a direct admission process, although such processes are not available at all institutions and may vary by the admitting provider. For instance, if a hospitalist is overseeing the hospital stay, they may prefer the admission to occur through the ED, whereas a primary care provider or oncologist may be more likely to facilitate a direct admission. Future research could address the extent to which admissions from the ED may be avoidable by examining reasons for and length of admission following an ED visit. While this study found top reasons for admission (principal diagnosis) to be septicemia, cardiovascular complaints and complications from surgery, cumulatively these diagnosis accounted for less than 20% of admissions from the ED. Examining frequent diagnoses by cancer type will also provide insight into potentially avoidable ED use, which may vary by disease course and treatment regimen.

The distribution of days from diagnosis to the first ED visit also varied by cancer type. This variation is likely attributable, at least in part, to differences in condition-specific treatment regimens, severity of illness, and stage at diagnosis. For example, patients with ED visits within 30 days of diagnosis may be those with advanced stage cancers who are at higher risk of complications, or they may be visiting the ED for post-surgical problems. Likewise, individuals who incur visits during later time periods may be undergoing longer treatment regimens. Further research is warranted to explore site-specific predictors of ED use and high-risk periods, accounting for cancer treatment and the timing of treatments.

In summary, ED use among cancer patients is substantial and higher than previously reported. Most ED visits occur within the first 180 days after diagnosis, suggesting focus on the first 30 days after hospital discharge may be misguided. Time frames for ED measurement in future research should be selected with careful attention to cancer-specific periods within which most ED use occurs and the outcomes of interest. Furthermore, better models identifying cancer-specific predictors of ED use, which account for treatment and comorbidities, will facilitate the development of interventions focused on high-risk segments of this population. Research is needed to explore cancer-specific reasons for ED visits and which ED admission diagnoses may be potentially preventable.