Healthcare Provider Confidence and Perceived Barriers to Diagnosing Illness Associated with Harmful Algal Blooms

Highlights • Illnesses caused by harmful algal blooms are difficult to diagnose.• A national survey of healthcare providers examined confidence and barriers to diagnosis.• Few respondents were confident in their ability to diagnose these illnesses.• Respondents cited a lack of knowledge as the most common barrier.• Providing information through preferred channels could increase provider confidence.


INTRODUCTION
Harmful algal blooms (HABs) occur when algae or cyanobacteria grow excessively, causing harm to humans, animals, or the environment.Factors that contribute to HABs in salt, brackish, and freshwater bodies include nutrient pollution (e.g., nitrogen and phosphorus run off from land-based sources) and warmer water temperatures. 1Climate change effects might alter the occurrence and severity of HABs in the U.S., increasing the risk to human health and well-being. 2 Health effects in humans are usually associated with exposures to toxins produced during a HAB.−6 To diagnose HAB-associated illnesses, providers need a basic awareness of HABs and the ability to identify clinical presentations and exposures.HAB-associated illnesses are primarily a diagnosis of exclusion because clinical testing options for HAB toxins are lacking; ideally, providers have access to clinical diagnostic testing to rule out other possible causes.Healthcare providers contribute to public health efforts when they identify and report HAB-associated illnesses to their jurisdictional health authority.For example, a healthcare provider diagnosis is a pathway to a confirmed case classification in the One Health Harmful Algal Bloom System, a national public health surveillance system used by state and territorial health departments. 7Electronic health records are being examined as another data source to characterize the human health impact of HABs. 8To explore the current state of confidence in identifying HAB-associated illnesses and perceived diagnostic barriers, we utilized a national survey of healthcare providers.

Study Sample
We conducted a descriptive analysis (SAS, Version 9.4) of data from the 2020 Porter Novelli DocStyles survey, a national web-based survey examining healthcare provider attitudes and behaviors (https://styles.porternovelli.com/docstyles/).All respondents were enrolled in an opt-in panel of healthcare providers and paid an honorarium of $20−$100 for completing the survey.Response quotas were set on the basis of specialty (e.g., 1,000 primary care physicians, 250 per specialty group).Eligible respondents were those (1) actively practicing and seeing patients in the U.S.; (2) working in an individual, group, or hospital practice; and (3) who had been practicing for at least 3 years.Centers for Disease Control and Prevention (CDC) licensed 2 questions within the survey to assess provider confidence and barriers related to diagnosing HAB-associated illness in patients.Demographic and occupational characteristic data were also examined.

Measures
Providers were first presented with a description of HABs and then asked about confidence: Algae or cyanobacteria can form HABs in waterbodies and sometimes produce toxins.Common exposures are water, including aerosols, and consuming seafood.How confident are you in your ability to identify signs and symptoms of illness caused by HABs?Select one.Responses were as follows: Very confident (almost every time), Confident (most of the time), Somewhat confident (some of the time), Not confident (very rarely if at all), or I do not see patients with these illnesses.
Providers were then asked about perceived barriers: What are the barriers, if any, to accurately diagnosing your patients with illness caused by HABs?Select all that apply.Respondents could select from Knowledge about these illnesses, Resources about clinical presentation, Access to diagnostic testing, Determining if my patients were exposed, or None of the above.

Statistical Analysis
The survey was administered between September 14 and October 26, 2020.A total of 1,503 providers, including primary care physicians, pediatricians, and nurse practitioners/physician assistants, completed the survey questions.The data set was deidentified before receipt by CDC; the analysis was exempt from CDC IRB review (this activity was deemed not to be research as defined in 45 CFR 46.102[l], and IRB review was not required).Chi-square tests were used to assess differences between groups, with statistical significance defined as p<0.05.

RESULTS
Of the 1,503 respondents, most (68%) reported little to no confidence in their ability to identify signs and symptoms of illness caused by HABs, 17% were either confident or very confident, and 15% reported not seeing patients with HAB-associated illnesses.Responses differed significantly by doctor specialization, work setting, sex, practice years, number of patients seen per week, whether pediatric patients were seen, and number of pediatric patients seen per week (Table 1).
Internists (21%) and family practitioners (18%) were more likely to be confident or very confident than other providers, and pediatricians were least confident (74%).Nurse practitioners (22%) and physician assistants (20%) were more likely to report not seeing patients with these illnesses.Confidence increased with provider age (23%), years in practice (22%), number of patients seen per week (30%), and number of pediatric patients seen per week (27%).Illness in children accounted for 40% of HAB-associated cases in 2019 and 25% of cases in 2020 reported to CDC. 9,10 These data suggest that children might be disproportionately impacted by HABs.Although seeing more patients per week, including pediatric patients, was correlated with increased confidence, pediatricians reported less confidence than any other occupational specialty.Therefore, pediatricians should be considered a key audience for information about HABs.
Using newspapers, professional medical societies, governmental agencies, medical journals, and medical websites as sources of information was positively correlated with provider confidence.Organizations conducting physician outreach should consider prioritizing these channels while exploring methods to reach additional providers.

Limitations
These survey results represent respondents' self-assessments, and we cannot quantify their accuracy.In addition, confidence is not equivalent to competence, a more difficult quality to assess.The survey did not distinguish between (1) providers not seeing patients with HABassociated illnesses and those unaware of seeing them or (2) providers who did not perceive any barriers and those who did not find a relevant barrier listed.Finally, there may be unmeasured factors contributing to differences in the frequency with which providers are using the types of channels described earlier (e.g., governmental agencies, professional medical societies).

CONCLUSIONS
Provider confidence in their ability to identify and accurately diagnose HAB-associated illnesses was low among all medical specialties, with knowledge about these illnesses identified as a primary barrier to confidence.Continued efforts to educate providers about HAB-associated illnesses, including how they occur and their clinical presentations, are needed to improve broader understanding and prevention of these illnesses nationally.Focused outreach should consider the potentially distinct needs of early career providers and pediatricians.This could leverage existing mechanisms for training and evaluating competency, such as through continuing medical education courses and medical examinations.Resource channels that are frequently used by providers can be leveraged to deliver information with the goal of further addressing knowledge gaps.

Table 1 .
Provider Confidence in Ability to Identify Signs and Symptoms of Illness Caused by HABs (N=1,503) (continued on next page)

Table 1 .
Provider Confidence in Ability to Identify Signs and Symptoms of Illness Caused by HABs (N=1,503) (continued) (continued on next page)

Table 1 .
Provider Confidence in Ability to Identify Signs and Symptoms of Illness Caused by HABs (N=1,503) (continued) Includes pediatric doctors.CDC, Centers for Disease Control and Prevention; HAB, harmful algal bloom.related to resources on clinical presentation and patient exposure, suggest that provider outreach could improve illness identification and diagnosis.Consideration of additional outreach to communicate which HAB-associated illnesses are of public health interest could further improve official reporting of these illnesses once diagnosed.
a Per week.b