Undiagnosed diabetes, hypertension, and overweight: Rates and their association with access to preventive care among Los Angeles adults

Background: People with undiagnosed chronic disease experience the highest risk for poor outcomes and complications of disease. Regular access to preventive medical care can provide opportunities for disease diagnosis and management before complications arise. Information about the rates of undiagnosed disease and risk factors for failure of diagnosis can inform policy interventions to target these high-risk groups.

Purpose: We investigate whether access to preventive care affects rates of diagnosis for three key chronic conditions: diabetes, hypertension, and overweight. We look at the frequency of undiagnosed disease by health insurance status, usual source of care, and demographic variables.

Methods: We use logistic regression in a representative sample of 1,406 adult residents of Los Angeles County to compare self-reported and measured disease status for each of three diseases. Data were collected using in-person interviews and health assessments in 2006-2008, as part of the Los Angeles Family and Neighborhood Survey.

Results: We observed very high rates of undiagnosed disease. Fifty-six percent of adults with measurable elevated blood sugar report that a doctor has never told them they have diabetes. Forty-five percent of adults with measurable hypertension (Stage I or II) have not been diagnosed with hypertension. Forty-seven percent of obese adults have not been diagnosed with obesity.

Our results also show that having a regular source of care of any type is an important step toward diagnosis for hypertension and excess weight. Furthermore, some population subgroups are at higher risk for having a failure of diagnosis, particularly male respondents, African Americans, people with lower education, and people at older ages.

Conclusions: Regular preventive care is an important factor in accurate and timely diagnosis, and a key step toward secondary prevention of poor outcomes. Improved access to doctors and basic diagnostic services among these subgroups could make a major contribution to successful secondary prevention.