The Diabetes Epidemic
The prevalence of diabetes mellitus is surging in the United States and globally, prompting experts to label it as the largest epidemic in human history Previous forecasts have consistently underestimated the number of individuals who would develop diabetes; for instance, the World Health Organization (WHO) projected 366 million cases by 2030, yet by 2015, the figure had already reached 415 million In the U.S alone, approximately 30 million people were living with diabetes in 2015, representing 9.4% of the population Furthermore, the WHO reported that diabetes was responsible for an estimated 1.6 million deaths worldwide in 2016.
Diabetes mellitus is a chronic metabolic disorder marked by high blood glucose levels, leading to significant macrovascular and microvascular complications, including cardiovascular disease, stroke, kidney disease, and limb amputations The most prevalent form is type 2 diabetes, which is associated with insulin resistance, while type 1 diabetes, or juvenile diabetes, results from inadequate insulin production Risk factors for type 2 diabetes are diverse, with obesity, physical inactivity, and poor dietary habits being major contributors Lifestyle modifications targeting these factors have proven effective in reducing diabetes incidence Additionally, non-modifiable elements such as genetic predisposition and epigenetic changes are gaining recognition as important risk factors.
Diabetes prevalence varies significantly among different racial and ethnic groups in the United States In 2015, the Centers for Disease Control reported that non-Hispanic blacks had a prevalence rate of 12.7%, followed closely by Hispanics at 12.1% In contrast, the rates were lower for Asians at 8% and whites at 7.4% Alarmingly, American Indians and Alaska Natives experienced a prevalence rate of 15.1%, more than double that of whites, highlighting the disproportionate impact of diabetes on Indigenous populations.
Aboriginal Australian and Native American communities experience the highest diabetes rates globally Additionally, Black, Hispanic, and Native American individuals face a greater risk of diabetes-related complications, including diabetic retinopathy, compared to their white counterparts.
Diabetic Retinopathy
Diabetic retinopathy (DR) is a serious complication of diabetes characterized by microvascular and neurodegenerative changes in the retina due to chronic hyperglycemia This condition leads to increased inflammation, oxidative stress, and vascular damage, resulting in non-proliferative retinopathy marked by endothelial injury in retinal blood vessels Such damage can cause microhemorrhages, microaneurysms, and leakage of lipids and plasma proteins, particularly affecting the macula and potentially leading to macular edema and vision loss As the disease progresses, retinal non-perfusion can result in proliferative diabetic retinopathy, where abnormal blood vessels grow and may cause retinal detachment and hemorrhage, significantly increasing the risk of severe vision loss Furthermore, the presence of DR is linked to a higher risk of systemic vascular complications, including stroke, coronary artery disease, and heart failure.
Diabetic retinopathy (DR) affects approximately 93 million people globally, with 28 million experiencing vision-threatening forms of the disease In the United States, DR is a leading cause of vision impairment and blindness, impacting about 30% of individuals with diabetes Both type 1 and type 2 diabetes can lead to DR, with nearly all type 1 diabetes patients eventually developing retinopathy Additionally, 50-60% of type 2 diabetes patients will experience some level of retinopathy in their lifetime, and up to 21% may have it at their initial diabetes diagnosis Alarmingly, one in ten individuals with diabetes will develop a vision-threatening variant of DR.
There are a number of risk factors for DR that are well-documented, including poor glycemic control, poor blood pressure control, and a longer duration of diabetes
While certain factors contribute to the risk of developing diabetic retinopathy (DR), much of the risk remains poorly understood Socioeconomic factors significantly impact the health of diabetes patients and their ability to manage these risks A patient's socioeconomic status can influence various aspects of their healthcare experience, including access to medical services, community resources, social support, diabetes knowledge, communication with healthcare providers, and adherence to treatment plans Additionally, the living environment, such as the safety and walkability of a neighborhood and access to healthy food, can further affect a patient's risk for diabetes and its complications.
Paralleling the racial disparities in the prevalence of diabetes, racial and ethnic minorities are also at increased risk of developing DR and vision-threatening forms of
DR [2,18–20] In one study that examined the third National Health and Nutrition
According to the NHANES III data, non-Hispanic Blacks exhibit a 46% higher prevalence of diabetic retinopathy (DR) compared to non-Hispanic Whites, while Mexican-Americans show an 84% higher prevalence In contrast, studies on Native Americans reveal limited data on DR rates, with historical reports from the 1980s and 1990s indicating a prevalence between 38-59%, whereas more recent research suggests a prevalence of 20%.
Prevention and Treatment of Diabetic Retinopathy and the Role of Screening
Diabetic retinopathy (DR) is a significant cause of blindness that is largely preventable, yet approximately 10% of individuals with diabetes will develop this vision-threatening condition Notably, DR often presents without early symptoms or warning signs, leaving many patients unaware of their diagnosis A study analyzing NHANES data from 2005-2008 revealed that only 26.1% of patients with DR, as shown in fundus photographs, reported being informed by a doctor about the impact of diabetes on their eyes Furthermore, among those with diabetic macular edema, only 44.7% acknowledged their condition.
Intensive control of glycemic levels and blood pressure is crucial in reducing the risk and progression of diabetic retinopathy (DR) A mere 1% decrease in glycated hemoglobin (HbA1c) can lower the risk of retinopathy by about 40% Maintaining tight blood pressure control, specifically below 150/85 mm Hg, can decrease the likelihood of DR progression by roughly one-third Effective treatments for preventing vision loss in proliferative DR include panretinal laser photocoagulation and intravitreal anti-vascular endothelial growth factor (VEGF) therapy, both targeting the pro-angiogenic signaling responsible for retinal neovascularization Anti-VEGF therapies are also applicable for diabetic macular edema, alongside intraocular steroids in certain situations In cases of tractional retinal detachment or persistent vitreous hemorrhage, vitrectomy may be required These interventions are highly effective, potentially reducing severe vision loss by 50-94%.
Early detection of diabetic retinopathy (DR) through routine eye examinations is crucial for preventing significant vision loss Screening for DR is essential due to its high prevalence among diabetic patients, the asymptomatic nature of early disease stages, and the availability of effective treatments that can alleviate the disease's impact Additionally, screening is a cost-effective measure, potentially saving around $100 million in federal healthcare costs each year.
Screening guidelines advise that individuals diagnosed with type 2 diabetes undergo a comprehensive dilated eye examination at diagnosis and annually thereafter For adult patients with type 1 diabetes, annual screenings should begin after five years of living with the condition While an ophthalmologist's clinical examination is the preferred method, practical limitations hinder the ability to screen every diabetic patient this way The introduction of non-mydriatic digital retinal photography presents a promising solution for large-scale screening.
Diabetic retinopathy (DR) screening can be effectively conducted in primary care by capturing retinal photographs These images can be sent to specialized reading centers for evaluation, allowing for timely referrals to ophthalmologists when necessary.
Utilization of Screening for Diabetic Retinopathy
Annual screening for diabetic retinopathy (DR) is crucial for early treatment and preventing vision loss; however, non-adherence to screening is alarmingly high, with studies indicating that 35-50% of diabetes patients do not receive necessary screenings Factors influencing eye care utilization include socioeconomic status, insurance coverage, access to healthcare, and race/ethnicity.
Research indicates that socioeconomic status significantly impacts eye health, with lower-income individuals and those with less than a high school education being less likely to have undergone an eye examination in the past year Studies by Zhang et al and Chou et al highlight these disparities, revealing that patients with age-related eye diseases, such as macular degeneration, cataracts, diabetic retinopathy, or glaucoma, are particularly affected.
Insurance status A study by Lee et al used data from the National Health
An interview survey investigating eye care utilization revealed that uninsured individuals had utilization rates of 14%, 24%, and 36% for no, some, and severe visual impairment, respectively In contrast, those with insurance demonstrated significantly higher rates of 34%, 54%, and 60% for the same levels of visual impairment This disparity highlights the impact of insurance on access to eye care services.
The Expenditure Panel Survey Household Component (2002–2009), which included the Diabetes Care Survey, revealed that insurance coverage was the primary determinant for individuals receiving eye examinations However, it also highlighted persistent racial and ethnic disparities in access to these examinations, even among insured patients.
Access to eye care is significantly lower for individuals in rural areas, and Native Americans face well-documented barriers to healthcare access and utilization, even in urban settings.
Racial and ethnic minority status is linked to lower rates of eye examination utilization and reduced access to eye care services Research by Lee et al highlights that specific Hispanic subgroups, such as Mexican Americans and Cuban Americans, exhibit particularly low rates of eye care utilization.
A population-based survey in Maryland revealed that only 50% of black participants aged 65-84 had seen an eye doctor in the past year, compared to 69% of white participants Additionally, a study at a large Indian Health Service clinic found that adherence to diabetic retinopathy screening was initially at 50%, but this rate increased to 75% following the implementation of a digital retinal imaging system in primary care.
Purpose of Current Study
Research indicates that patient populations suffering the most from diabetic retinopathy, particularly racial and ethnic minorities as well as individuals with low socioeconomic status, are the least likely to undergo essential screening examinations This highlights a critical disparity where those in greatest need of screening are often the ones who do not receive it Various interconnected biological, socioeconomic, and environmental factors contribute to the risk of developing diabetes and its complications, as well as affecting the utilization of screening services.
Understanding and intervening upon these factors is key to improving outcomes for patients with diabetes
Despite extensive data on disparities in diabetic retinopathy (DR) screening, there is a lack of studies focusing on patient perspectives, particularly among high-risk groups such as racial/ethnic minorities and individuals with low socioeconomic status Research indicates that perceived barriers to eye care include cost, insurance issues, transportation, communication gaps with physicians, distrust in the healthcare system, and a lack of awareness about the need for examinations Notably, a study in North Carolina highlighted that distrust in providers was a significant barrier for under-utilizers of eye care Additionally, findings revealed that many patients lacked knowledge about eye health and received little counseling from primary care providers Furthermore, focus groups with diabetic patients and healthcare professionals identified a lack of awareness regarding insurance benefits as a primary barrier for patients, while physicians noted a lack of education on the importance of eye exams as a key issue.
Research is essential to understand the experiences of high-risk diabetes patients, particularly among racial and ethnic minorities and those with low socioeconomic status, in relation to diabetic eye care Identifying the factors that affect their access to eye care is crucial for developing effective interventions aimed at increasing screening rates and reducing the burden of diabetic retinopathy (DR) This study presents findings from qualitative interviews with high-risk diabetic patients at a federally qualified community health center, highlighting their experiences with DR screening and proposing a theoretical framework to characterize the influencing factors on diabetic eye care receipt in this population.
I Qualitative Methods and Their Utility
Qualitative research aims to understand the reasons behind phenomena by utilizing non-numerical data It primarily employs inductive reasoning to generate hypotheses rather than testing them According to Curry et al., qualitative methods are effective in describing various phenomena.
While quantitative methods have traditionally dominated health sciences research, many modern health phenomena are challenging to quantify This includes intricate social processes, the beliefs and motivations influencing health behaviors, and the broader social, political, and economic contexts affecting health The aim is to achieve a deeper understanding and potentially formulate hypotheses about these phenomena, their origins, and their impacts.
Qualitative methods provide valuable insights into the varied experiences of patients, especially those from at-risk communities This research approach involves collecting data through observational techniques, such as one-on-one interviews or focus groups, focusing on individuals with relevant experience or knowledge The analysis of qualitative data is iterative, involving collection, coding, and interpretation, which often leads to the identification of recurring themes, hypotheses, or conceptual models.
This study aims to explore the factors affecting diabetic retinopathy (DR) screening utilization among patients from racial and ethnic minority groups, as well as those with low socioeconomic status Given the complexity of this issue, qualitative methods are particularly suited to uncover the personal choices and influences that shape individual patients' decision-making processes.
This study utilized grounded theory principles to systematically gather and analyze data, developing theories through inductive reasoning Qualitative data was reviewed, with repeated concepts tagged as "codes" that were refined with additional data collection These codes were then organized into concepts and larger categories, potentially forming the foundation for new theories This approach enables researchers to create a theoretical account of a topic's general features while grounding it in empirical observations.
Setting
The study protocol received approval from the institutional review board at Yale University, which exempted it from ongoing oversight Input from local community health organization leaders, facilitated by the Yale Center for Research and Engagement, played a crucial role in shaping the study design The center's mission is to foster collaboration between community organizations and trainees to develop and execute research projects focused on priorities identified by the New Haven community.
Semi-structured qualitative interviews were carried out with diabetes patients at the Cornell Scott Hill Health Clinic, a federally-qualified community health center (FQHC) located in New Haven, CT, along with its satellite clinics in the surrounding area.
In Ansonia, CT, and at the Yale Primary Care Clinic in New Haven, CT, additional interviews were conducted, focusing on a patient population that is predominantly 69% Black or Latino, with 64% of patients living below the poverty line The Yale Primary Care Clinic caters to a similar demographic, with interviews taking place in various settings, including primary care clinics, a diabetes and wellness education center, and an on-site eye clinic.
Participants
A convenience sample of English-speaking patients with diabetes was recruited by approaching patients before or after their appointments Author E Fairless recruited
A total of 30 participants were involved in the study, with 26 recruited by A King, a medical student, who also brought in the remaining 6 participants All individuals provided written informed consent, including permission for audio recording While the first 24 participants did not receive any compensation, the last 6 were given $20 gift cards for their participation The study exclusively included patients diagnosed with diabetes for a minimum of one year Demographic information was self-reported by participants, covering aspects such as age, gender, race/ethnicity, insurance status, duration since diabetes diagnosis, time since their last eye exam, and the frequency of eye exams.
Participant Interviews
Semi-structured qualitative interviews were conducted in English with participants in a one-on-one setting, with E Fairless leading 24 of the 30 interviews and A King conducting 6 Following grounded theory principles, the interviews aimed to generate hypotheses rather than test existing ones Participants responded to open-ended questions regarding their experiences with eye exams, the factors influencing their decisions to seek or avoid eye care, and any barriers encountered in accessing these services The interview guide used to direct the questioning was developed by E Fairless.
When was the last time you had an eye exam? How often do you get eye exams?
Can you tell me about your experience the last time you had an eye exam?
What made you decide to get an eye exam? What motivated you to go?
At the time that you were diagnosed with diabetes, what, if anything, were you told about eye care?
Have you ever been told by a healthcare provider that diabetes can affect your eyes?
How did you learn that diabetes can affect your eyes?
Has anything ever prevented you from having an eye exam? Have you ever cancelled or not shown up to an eye exam appointment? If so, why?
Follow-up questions were employed to prompt participants to provide more detailed responses The author regularly assessed and revised the interview guide using a reflection checklist to maintain clarity and ensure internal validity.
Data Analysis
The interviews were recorded using a H4next Handy Recorder and transcribed verbatim with Trint online transcription service The analysis was conducted using NVivo software, version 11, following the principles of grounded theory The transcripts were examined line by line to create inductive codes that defined key concepts Overarching themes were identified, and the coding framework was refined until a comprehensive structure was established All interviews were reviewed and coded by author E Fairless, with additional review and validation by Dr K Nwanyanwu.
The coding framework established by E Fairless and Dr K Nwanyanwu serves as the foundation for a theoretical model that examines the factors influencing screening utilization This model is structured within a socio-ecological framework, which contextualizes health behaviors by considering individual factors such as attitudes and behaviors, social factors including social networks and support, and structural factors like access to care.
Participant Demographics
A total of 30 people participated in the study The median age of participants was 57.3 (range 35 –73) Fifteen participants identified as female and 15 as male
The study included participants identified as black (16), white (5), Hispanic (5), Asian (1), and other/declined to answer (3) Among the 28 participants, 24 had received an eye exam in the past year; however, one-third (10) reported not having yearly eye exams Additionally, half of the participants had been living with diabetes for over 10 years Detailed demographic information is presented in Table 2.
Demographic Information N = 30 Age, median (range) 57.3 (35-73)
Most Recent Eye Exam, No (%)
Within previous 12 Months 24 (80) Not within previous 12 months 6 (20)
Annually or more frequently 20 (66) Less frequently than annually 10 (33)
Interview Comments
A total of 415 interview comments were analyzed and categorized into 22 nodes across 7 overarching themes, which were divided into individual and institutional/structural factors based on a socio-ecological model Individual factors encompassed vision status, competing concerns, and emotional context, while institutional and structural factors included resource availability, in-clinic experience, cues to action, and knowledge-creating experiences This coding framework served as our theoretical model for understanding the factors influencing the utilization of eye examinations within our patient population.
Figure 1: Theoretical framework of factors affecting utilization of eye exams in patients with diabetes, and representative quotes from participants
Individual factors play a crucial role in patient experiences, encompassing vision status, competing concerns, and emotional context These factors are specific to each patient, including their attitudes, behaviors, and health issues, as well as elements closely tied to their daily lives.
Many participants reported that changes in their vision or the need for updated corrective lenses were the main reasons for seeking eye exams One individual with diabetic retinopathy shared that he delayed his eye exam until a retinal hemorrhage significantly impacted his vision, stating, “I blew off the first appointment, and then I was half-blind.” Another participant noted that noticing a difference in their eyesight motivated them to get an exam Additionally, several participants mentioned that the annual need to update their glasses independently encouraged them to schedule eye exams, regardless of the necessity for diabetic retinopathy screening One participant with gout expressed the struggle to attend the eye clinic, emphasizing, “I made it here, I struggled Again, because I want some new glasses.”
Participants highlighted that various competing concerns, including other health issues, childcare duties, addiction struggles, and work schedules, significantly impacted their ability to attend regular eye exams One individual shared her experience of having to cancel multiple health appointments due to her job, stating, “I canceled a few appointments over the last three months because I had a new job So now I'm going to work on getting all those appointments rescheduled and done because I'm not working now.”
Many participants expressed fear or hesitation regarding eye exams, primarily due to concerns about receiving bad news or undergoing painful procedures One individual noted, “I didn't think I needed [an eye exam] And a lot of times when I go to the doctor all of a sudden I need stuff And I didn't want that to happen, I wanted to think that my eyes were going to be OK.” Conversely, some participants were motivated to seek exams out of a desire to stay informed about their health, often prompted by significant health events, such as hospitalizations, that served as a “wake-up call” to take proactive steps in accessing healthcare.
Institutional and structural factors significantly impact the accessibility of eye care services Key elements include the availability of resources, the quality of in-clinic experiences, cues that prompt action, and opportunities for knowledge creation These factors encompass the dynamics of the patient-provider relationship, the overall healthcare system, and broader social structures.
Resource availability significantly impacts access to eye care, particularly for those who have not had an eye exam in the past year Many participants cited financial constraints as a primary reason for not seeking eye exams, with one single parent stating, “I didn’t have the money to pay for the amount of money [the eye clinic] said that I had to pay.” Another participant echoed this sentiment, noting that ongoing eye symptoms were overlooked due to financial limitations Uninsured individuals faced additional barriers, with one participant revealing she had not received an eye exam in five years due to lack of insurance, despite her doctor's recommendations Many participants reported receiving eye exams only every two years, mistakenly believing that their insurance did not cover annual exams, even though most plans typically cover medically necessary eye exams for patients with diabetes annually.
Access to transportation to the eye clinic was generally not an issue for most participants However, some individuals faced barriers such as homelessness or incarceration, which hindered their ability to seek eye exams One participant highlighted the lack of eye care services while incarcerated, stating, “I was in prison, so they didn’t- they don’t do all that [eye care] So when I came home I got everything done.”
Participants in the clinic highlighted that their communication with healthcare providers significantly impacted their eye care experiences One patient shared a positive perspective, stating, “The diabetes has not affected me so far from what [the doctor] tells me when she sees me in here [at the eye clinic.] I think the process works They are on top of it every year when they go in they are doing the full work up on me and letting me know that nothing's happening so far.” Conversely, another participant expressed concerns about receiving conflicting information from her providers.
I continue to experience blurred vision, despite receiving mixed opinions from different sources Some say it's normal, while others mention a trace of cataract, advising me not to worry What steps can I take to address this ongoing issue?
Participants highlighted significant miscommunication in their eye care experiences, with one individual mistakenly thinking that retina surgery would involve the removal of his eye Additionally, feelings of respect from their eye doctors and positive interactions with clinic staff were crucial factors that shaped their overall experience with eye care.
Participants indicated that reminders from primary care providers significantly influenced their decision to undergo eye examinations One participant noted, “If the doctor suggested I have an eye exam, I would have followed the instructions, regardless of whether I had diabetes or not.”
A participant highlighted the significance of eye exams, stating that without guidance, they might not have recognized its importance This underscores the value of proper referrals in promoting eye health awareness.
My doctors recommended an eye exam to check for any damage caused by my diabetes and high blood pressure, as both conditions can affect eyesight They referred me for the appointment, which was arranged through a phone call.
In contrast, another participant felt that eye care was not emphasized by his primary care provider, which delayed his seeking an eye exam:
“I should have been scared into going [to the eye doctor] a little bit, or at least, you know, given some kind of explanation as to what [diabetic retinopathy] was
Diabetes has led to various side effects for me, including neuropathy However, I have noticed that my vision issues seem to be particularly concerning.
Participants also reported that following an annual exam schedule and getting appointment reminders were useful prompts to seek eye exams