One of the benefits of public healthcare is the enormous datasets it unleashes, which can be analyzed with a much higher degree of confidence than small samples. A case in point is the state of Minnesota, a Medicare-expansion state known for a strong public health system.

One of the pillars of Minnesota’s healthcare system is the Mayo Clinic in Rochester, Minnesota — the original Mayo Clinic campus and still the largest. Researchers from the Mayo Clinic Department of Psychiatry and Psychology have just published a report on how sex, race and ethnicity impact substance use disorder (SUD) treatment attrition.

What do they mean by “treatment attrition”? These are patients being treated for SUDs who dropped out or were kicked out before concluding treatment. The researchers looked at anonymized data, trying to determine if outcomes were different based on sex, race, and ethnicity.

Here’s where the large dataset comes in. The Mayo Clinic had records of nearly 4 million admissions for SUD treatment from 2017 to 2021. Overall, 1.6 million were first admissions, or 42%. Here’s what researchers found regarding sex, race and ethnicity:

• Women had significantly higher attrition rates than men
• Black and Latina women had double the attrition rate of white women 
• White males were overrepresented in repeat admissions
• Latina females were 22% less likely to be readmitted

The researchers concluded:

Black and Latina females face compounded barriers to retention and re-engagement.

Moving from an analysis of the data to causation is always problematic. The fact that Latina women drop out of treatment more often is a problem. The fact that Latina women do not readmit as often is not necessarily a problem. It could be a sign of not needing to readmit, thus an improvement.

An earlier study from the UCLA healthcare system shows the problems of a small dataset. Their survey into the persistence of SUDs by gender, race, and ethnicity is based on only 2,860 patients. However, it contains a three-year follow-up after SUD treatment, giving it some longitudinal weight.

Findings in this report include:

• A minimum of 31% relapse rate, regardless of the substance used
• “SUD persistence rates were consistently higher among poly-substance users.”
• Black men were less likely to persist using than white men.
• Hispanic men were less likely to persist using than white men.

One of the study’s findings, which could help explain Latina women’s lower return rate from the Mayo study, is that Hispanics being treated for alcoholism were less likely to persist in using than whites. Another way of stating this is that Latina women have a significantly higher addiction treatment success rate.

In a fascinating study on the differences between SUDs reported in surveys and SUDs actually seen through electronic health records, researchers on the West Coast, from Seattle to Los Angeles, studied the records of the Veterans Health Administration to see if there is a demographic bias in the treatment of SUDs.

Researchers conducted a randomized telephone survey of 5,995 VA outpatients, then tracked electronic health records. The results: “The survey-based prevalence rates of AUD, DUD, and SUD were higher than the diagnosis rates among all patients.” They suggest this outcome is due to a failure of the VA medical staff to correctly diagnose SUD.

As far as the demographic discrepancies, age was surprisingly the largest factor, with young people disproportionately misdiagnosed. Hispanic and Latinx patients were the next, being less likely to receive a correct diagnosis than the average.

The conclusion of the researchers is basically, if we can diagnose these people correctly in a phone call, why can’t you ask the same questions and reach the same conclusions in person? They call on health systems to “implement standardized SUD assessments to ensure the provision of equitable care,” and to pay more attention to young persons and Hispanics.

Written by Steve O’Keefe. First published October 16, 2025.

Sources:

“Sex, Race, and Ethnicity as Intersectional Predictors of Outpatient Substance Use Disorder Treatment Attrition,” Substance Abuse and Rehabilitation, October 9, 2025.

“Gender and race/ethnic differences in the persistence of alcohol, drug, and poly-substance use disorders,” Drug and Alcohol Dependence, May 1, 2017.

“Comparison of Substance Use Disorder Diagnosis Rates From Electronic Health Record Data With Substance Use Disorder Prevalence Rates Reported in Surveys Across Sociodemographic Groups in the Veterans Health Administration,” JAMA Network Open, June 30, 2022.

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