The Uneven Burden of Idiopathic Intracranial Hypertension in US Women

TOPLINE:

Idiopathic intracranial hypertension (IIH) affects 3.44 per 10,000 women aged 18-55 years in the United States. Significant geographic variation in cases of the condition exists, potentially reflecting factors such as the prevalence of obesity.

METHODOLOGY:

• Researchers conducted a retrospective cross-sectional study using data from Medicaid claims and electronic health records from the IRIS Registry and Sight Outcomes Research Collaborative to determine the prevalence and geographic distribution of IIH among women in the United States.
• They analyzed 13,959 female Medicaid beneficiaries aged 18-55 years with IIH, of whom 6828 were prescribed acetazolamide or methazolamide in 2018.
• The proportion of women receiving active treatment for IIH was estimated by dividing the number of Medicaid beneficiaries with IIH by the proportion of patients with IIH insured by Medicaid. Data from the 2018 American Community Survey were used to determine the prevalence of IIH in this population.
• The geographic variation of IIH across the country was compared with the prevalence of obesity, the primary risk factor for IIH.
• Lastly, validation was performed by comparing the calculated prevalence of IIH in Minnesota with the data from the Rochester Epidemiology Project.

TAKEAWAY:

• The prevalence of IIH was estimated to be 3.44 per 10,000 women (95% CI, 2.61-5.39).
• Significant geographic variation was observed in the prevalence of IIH in the United States (P = .03); the states with the highest prevalence of IIH were Kentucky, followed by Louisiana, Ohio, and Rhode Island. (Washington, DC, had the third highest prevalence.)
• As expected, many states with a greater prevalence of obesity also reported a higher prevalence of IIH; however, certain states such as Texas, Oklahoma, and Alabama, exhibited a high obesity rate while maintaining a relatively low prevalence of IIH.
• The calculated prevalence of IIH in Minnesota was statistically equivalent to the data from the Rochester Epidemiology Project (P

IN PRACTICE:

“These findings provide new insights into the public health significance of IIH and may help guide future research on socioeconomic and environmental risk factors, healthcare utilization, and health disparities and outcomes of this and other rare eye diseases,” the authors of the study wrote.

“Understanding the regional distribution of IIH is also important for contextualizing the availability of certain limited healthcare resources such as neuro-ophthalmologists and may inform enrollment strategies for IIH research studies by targeting recruitment efforts to areas with a higher prevalence,” they added.

SOURCE:

The study was led by Muhammad A. Fraz, MD, of the Departments of Neurology and Ophthalmology at the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, and was published online on November 6, 2024, in Ophthalmology.

LIMITATIONS:

The data used in the study did not capture clinically relevant information such as papilledema or cerebrospinal fluid opening pressure, which would be important for diagnostic confirmation. Patients who had mild disease may have been lost to follow-up. Medicaid beneficiaries were assigned to the state in which they had the longest eligibility period in 2018; however, this may not have aligned with the period during which a person was diagnosed and treated for IIH, potentially biasing state-level estimates.

DISCLOSURES:

One author reported receiving support by a grant from the National Eye Institute. The authors declared no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.