Underdiagnosed and Undertreated Depression Among Racially/Ethnically Diverse Patients With Type 2 Diabetes

Data were collected at five primary care clinics affiliated with an academic medical center in Southern California (8). Patients were excluded if they were age ≥80 years, had a diagnosis of schizophrenia, or could not speak English, Spanish, or Vietnamese. Of the eligible patients approached, 76% consented to complete the baseline survey and to allow access to their medical record information, laboratory, and administrative data. Patients completed an informed consent and a Health Insurance Portability and Accountability Act (HIPAA) waiver to obtain consent to review their medical charts. The research design, survey questions, and study procedures were approved by the University of California, Irvine’s Institutional Review Board.

An 11-item version of the Center for Epidemiological Studies Depression (CES-D) scale (9) was used to assess severity of depressive symptoms. This version, abbreviated from the full 20-item CES-D, has been validated against other psychiatric measures of depression in ethnically diverse samples (4) and exhibited good internal consistency for each racial/ethnic group (Cronbach α ranged from 0.90–0.92). Scores on the abbreviated measure were rescaled to have the same range of values as the full measure. A cutoff score ≥22, which has been shown to have good sensitivity and specificity for screening for major depressive disorder among chronically ill patients (10), was used to indicate clinically relevant levels of depressive symptoms.

Technical quality of diabetes care was measured using performance measures for process of care (e.g., annual performance of HbA_1c, lipids, blood pressure, and foot and eye examinations), as specified by the National Committee for Quality Assurance (NCQA) Diabetes Recognition Program (11). Three measures of provider recognition and treatment were collected: 1) documentation of a diagnosis of depression in patients’ medical records (e.g., in the problem list, chart notes, or referrals to mental health providers), 2) documentation of a prescription for an antidepressant medication either being currently taken by the patient or prescribed by a provider in the year before study enrollment, and 3) patient report of having seen a mental health provider (e.g., psychologist, psychiatrist, counselor) in the past year.

Group differences in patient characteristics were evaluated using ANOVA (Table 1). Logistic regressions were conducted to examine racial/ethnic differences in the technical quality of diabetes care and in the detection and treatment of depression among the subsample of patients with depressive symptoms. These analyses included the following variables as covariates: age, sex, marital status, duration of diabetes, number of chronic conditions, and insurance status. The Bonferroni procedure was used to control for type I error across multiple comparisons. Two-tailed P values ≤ 0.01 were considered statistically significant.

Finally, we evaluated patient-level factors associated with physician recognition and treatment of depression in minority patients with high levels of depressive symptoms using a logistic regression model entering patient sociodemographic characteristics, health status, and doctor-patient relationship characteristics (i.e., trust in provider [12], language concordance [13], duration of relationship with doctor [14], and number of appointments in the past year).

Mexican American (87.4%) and Vietnamese American (97.3%) patients had largely limited English proficiency. More Vietnamese American (59.4%) and Mexican American (50.2%) patients reported symptoms consistent with clinical depression (CES-D score ≥22) compared with whites (41.6%; F [2, 1206] = 8.05, P < 0.001).

Despite comparable process quality among patients with symptoms indicative of depression, significant racial/ethnic differences in mental health diagnosis and treatment were found. Specifically, there were no ethnic/racial differences in recommended processes of diabetes care.

Compared with non-Hispanic whites, however, Mexican American and Vietnamese American patients with depressive symptoms were significantly less likely to have had a diagnosis of depression and/or prescription for an appropriate medication noted in their chart (all P values < 0.001) and were less likely to have any depression treatment noted (all P values < 0.001), even after adjustment for covariates. Consistent with our hypothesis, a higher proportion of minority patients reported symptoms indicative of clinical depression, yet were less likely to be diagnosed and treated compared with non-Hispanic whites.

Logistic regression models examining patient characteristics associated with recognition or treatment of depression showed that, among Hispanic and Vietnamese patients, individuals who report low levels of trust in their provider were less likely to have been diagnosed or treated for depression (data not shown, adjusted odds ratio 0.65, 95% CI 0.44–0.98, P < 0.05).

Despite comparable quality of diabetes care, physicians appeared not to recognize or treat depressive symptoms adequately, particularly among minority patients. This situation appeared to be particularly problematic for minority patients who reported low levels of trust in their provider, highlighting the importance of a high-quality doctor-patient relationship in addressing depressive symptoms.

There are several limitations to this study. First, although the CES-D has been widely used in community studies of depression, it also may reflect general psychological distress and diabetes-specific depression, which are both different from clinical depression (15). Nevertheless, because patients who display high levels of distress have worse diabetes outcomes, greater attempts are needed to target the underlying causes of the distress. Second, there are other possible explanations for the lack of agreement between the provider- and patient-reported depressive symptoms other than lack of provider recognition. Chart reviews may not reflect providers’ awareness of depression because providers may hesitate to document emotional symptoms.

In summary, the findings suggest that without culturally appropriate interventions in primary care, depression will continue to be suboptimally detected and managed in minority patients, and racial and ethnic disparities will persist.

This work was supported by the Robert Wood Johnson Foundation (grants 1051084 and 59758), the Novo Nordisk Foundation, and the National Institute of Diabetes and Digestive and Kidney Diseases (R18DK69846 and K01DK078939).

No potential conflicts of interest relevant to this article were reported.

D.H.S. researched data, contributed to discussion, wrote the manuscript, and reviewed and edited the manuscript. Q.N.-M. contributed to discussion and reviewed and edited the manuscript. J.B. researched data, contributed to discussion, and reviewed and edited the manuscript. K.J.A. contributed to discussion and reviewed and edited the manuscript. S.G. researched data and contributed to discussion. S.H.K. researched data, contributed to discussion, and reviewed and edited the manuscript.

Parts of this study were presented at the 33rd Annual Meeting of the Society of General Internal Medicine, Minneapolis, Minnesota, 28 April–1 May 2010.