Diagnosis of Huntington Disease: Black Vs White Patients Experience 1-Year Delay

Black vs White patients experience a 1-year delay in time from symptom onset to time of diagnosis of Huntington disease (HD), according to study results published in Neurology: Clinical Practice.

Researchers conducted a cross-sectional study using data from the ENROLL-HD periodic data set 5 to examine racial disparities in the time from symptom onset to diagnosis of HD among gene-positive individuals (CAG repeats 36+) in North America.

Potential moderators and mediators of the relationship between race/ethnicity and time to diagnosis included biological variables (ie, age at symptom onset, sex, family history of HD, type of initial symptom at disease onset, and CAG repeat length), as well as social determinants of health (SDOH; ie, education, employment status, residential location).

The primary outcome was time to HD diagnosis. Multivariate linear regression models were used in statistical analysis.

A total of 4717 patients (mean age at symptom onset, 44.6; mean age at diagnosis, 48.08; White, 89.5%; women, 55.9%) were included in the final analysis.

The average time to diagnosis was 3.78 years; however, the average time to diagnosis among Black, Latino, Asian, and Native American patients was 4.6, 4.2, 4.2, and 4.1 years, respectively.

Compared with White patients, Black patients were diagnosed approximately 1 year later (P < .01). Similarly, men vs women were diagnosed 0.4 years later (P <.05 and P <.01, depending on the model).

Patients with psychiatric vs motor symptoms as the initial symptom type were diagnosed 1 year later (P <.001). Those with no and unknown family history of HD vs those with a known family history of the disease were diagnosed 1.6 and 2 years later (P <.001), respectively. Patients who were unemployed vs employed full-time at baseline were diagnosed 1.3 years later (P <.001). Further, patients with a PhD/doctorate degree vs those with a high school degree or GED equivalent, were diagnosed 1.7 years later (P =.001).

Results were sustained in sensitivity analyses, which included gene-positive patients with a total motor score of at least 10 and those with 40+ CAG. Black vs White patients were diagnosed 1.2 years later (P =.015), men vs women were diagnosed 0.4 years later (P =.017), and those with psychiatric vs motor symptoms at disease onset were diagnosed 1 year later (P <.001).

Regarding SDOH, unemployed patients vs patients who were employed full-time at baseline were diagnosed 1.4 years later and those with a PhD/doctorate degree vs those with a high school degree or GED equivalent were diagnosed almost 1.7 years later.

Study limitations included selection bias and missing data. “Additional multicenter qualitative and quantitative studies are needed to better understand reasons for delays in HD diagnosis among Black individuals, and the role of social and structural determinants of health in obtaining a timely HD diagnosis,” the researchers concluded.