Recurrent Diabetic Ketoacidosis in Inner-City Minority Patients

CONCLUSIONS

This study determined clinical, socioeconomic, and psychological factors associated with the recurrence of DKA in inner-city minority patients. Our results indicate that discontinuation of insulin therapy was the major precipitating cause and accounted for over two-thirds of all DKA admissions. Several behavioral, socioeconomic, and psychosocial factors contributed to poor treatment adherence. Among patients with poor compliance with insulin therapy, one-third of patients “just stopped” (gave no clear reason for stopping insulin), one-third reported financial troubles, and most of the rest reported being away from their supply (lost, stolen, etc.) or did not know how to handle insulin on sick days. In addition, about one-half of patients with recurrent DKA who discontinued insulin had a history of alcohol or drug abuse or depression.

Insulin discontinuation has long been recognized as an important precipitating cause of DKA in retrospective studies. Observational studies in urban African Americans have reported that more than one-half of DKA cases in patients with diabetes were caused by noncompliance with insulin therapy (7,12). Likewise, a retrospective study in a multiethnic population in Texas listed noncompliance with insulin injections as their most common precipitating cause of DKA (10). Our study confirms that poor compliance with insulin therapy is the leading precipitating cause among inner-city patients, accounting for 56% of patients with their first episode and 78% of patients with recurrent DKA admissions. The average number of previous DKA episodes for patients admitted to our institution was 3.54, with 18 patients having ≥10 DKA admissions (1 patient having 39 DKA admissions to Grady Memorial Hospital).

The importance of psychological factors in the incidence of DKA has been emphasized in recent studies. In a survey of 341 female patients with type 1 diabetes (11), it was reported that psychological problems complicated by eating disorders were a contributing factor in 20% of recurrent episodes of ketoacidosis in young women. More recently, it was reported that up to one-third of young women with type 1 diabetes have eating disturbances (18). In our study, all patients underwent screening for depression by patient-reported history, previous use of antidepressant agents, and with the PHQ-9 survey. A total of 46% of patients had a self-reported history of depression and 36% of patients had taken antidepressants prior to admission. The mean PHQ-9 score was 9.8 ± 7.4, which is suggestive of mild to moderate depression. Among patients with a history of being treated with antidepressant medications, the median PHQ-9 score was 13, representing moderate depression. A history of depression was higher among patients with recurrent admission with DKA; however, there were no differences in PHQ-9 scores among those multiple episodes compared with those with a single episode of DKA. Sixty (37%) patients overall had PHQ-9 scores showing moderate to severe depression. This is slightly higher than the average of 32% of diabetic patients in controlled studies (19). Several patients also had more serious mental health disorders, with 3.0% of the cohort carrying a diagnosis of bipolar disorder or schizophrenia.

Despite a mandatory policy at our institution of providing inpatient diabetes education to all patients with DKA and the fact that 72% of patients previously received diabetes education, we found that fewer than one-half of our patients understood the meaning of A1C or knew their most recent value. In addition, many patients were unaware of sick-day management or the consequences of skipping or discontinuing insulin therapy. Many patients believed that because their insulin doses normally correspond with meals, if they are feeling too sick to eat, they do not need to take insulin. These results indicate that diabetes education and sick-day management should be reviewed periodically in all patients with diabetes. It should include specific information on when to contact the health care provider, blood glucose and A1C goals, use of supplemental short- or rapid-acting insulin during illness, and, most importantly, the importance of never discontinuing insulin and of seeking immediate medical attention in the case of severe hyperglycemia. Because most people learn best through repetition, diabetes education should be repeated at least yearly, with review of basic concepts and additional supplemental concepts as well as checks for understanding and modifications for patients with recurrent DKA. A recent study in adolescents reported that an intensive home-based multidisciplinary intervention resulted in a significant decrease in DKA admissions over 2 years (20). In that study, a multidisciplinary diabetes team met with study patients frequently and addressed barriers to communication, access to care, and medical adherence on the family, school, and health care levels. Despite the expense of providing such an intensive intervention, the multidisciplinary intervention incurred less cost to the health care system as a result of a decreased number of DKA admissions.

Significant resources are spent on the cost of DKA hospitalizations. It is estimated that DKA episodes represent more than $1 of every $4 spent on direct medical care for adult patients with type 1 diabetes and $1 of every $2 in those patients experiencing multiple episodes (21). Based on an annual average of 135,000 hospitalizations for DKA in the U.S., with an average cost of $17,500 per patient, the annual hospital cost for patients with DKA may exceed $2.4 billion per year (5). Because most cases occur in patients with known diabetes and with previous DKA, the majority of DKA admissions could be prevented by improved access to medical care, proper education, and effective communication with a health care provider during an intercurrent illness. Our results, together with previous reports on the prevalence of poor compliance as a common precipitant of DKA (7,10,12), underscore the need for our health care delivery systems to address this problem. The high frequency of insulin discontinuation (often for economic reasons) as the precipitating cause for DKA illustrates the need for health care legislation for reimbursement for medications and universal health care.

We acknowledge several limitations in our study, including a relatively small number of patients and the fact that our patient population included mostly inner-city African American patients admitted to a single medical institution; thus, the information may not be extrapolated to other ethnic groups or populations. A large prospective study including different ethnic groups with diverse social and economic backgrounds and insurance coverage, from academic and community hospitals in rural and urban populations, is certainly needed to better understand underlying socioeconomic, educational, and cultural factors that lead to the high rate of poor treatment adherence and recurrent DKA.

In conclusion, this cross-sectional observational study indicates that poor adherence to insulin therapy is the leading precipitating cause of DKA in inner-city minority patients. Lack of adherence to insulin treatment relates to a multitude of socioeconomic and psychosocial factors. Novel approaches to patient education incorporating a variety of health care beliefs and socioeconomic issues are critical to an effective prevention program. Because DKA represents an important financial burden and health care problem in inner-city populations, it would be wise to invest resources in expanding health care coverage and medication cost as well in developing strategies to increase treatment compliance and prevent DKA admissions.