Analysis of patient claims data to determine the prevalence of hidradenitis suppurativa in the United States

Background: Recent prevalence estimates for hidradenitis suppurativa (HS), a chronic inflammatory skin condition, are limited by timeliness, population size, and generalizability.

Objective: We sought to develop prevalence estimates for HS in the United States using large health care claims databases.

Methods: A retrospective analysis used PharMetrics Integrated Database to gather health care claims information for HS among patients with 12 or more months of continuous enrollment in a commercial health care plan throughout 2007. Included patients had: 1 or more diagnoses with International Classification of Diseases, Ninth Revision, Clinical Modification code 705.83 for HS during 2007 without a Current Procedural Terminology code for HS; 1 or more Current Procedural Terminology codes of 11450, 11451, 11462, 11463, 11470, or 11471 during 2007 without International Classification of Diseases, Ninth Revision, Clinical Modification code 705.83; or both. Age- and gender-specific prevalence projections were calculated.

Results: Among included patients (n = 7927), mean age (SD) was 38.2 (14.73) years, and 5834 (74%) were women. Most patients (n = 5205; 66%) were aged 30 to 64 years. The overall prevalence estimate was 0.053% (95% confidence interval 0.051-0.054). When adjusted for gender and age, prevalence rates were 0.052% and 0.051%, respectively. The most common procedures for HS were excision of skin and subcutaneous tissue axillary/inguinal simple or intermediate repair.

Limitations: Limitations were a health insured-only population; 12-month enrollment period for 2007; HS-specific procedural codes; and possible HS misclassifications.

Conclusion: We found a low rate of clinically detected HS (0.053%; approximately 146,000-162,000 patients in the United States in 2007), with affected persons almost 3 times as likely to be female and the highest prevalence in those aged 18 to 44 years.