Medicare claims data reliably identify treatments for basal cell carcinoma and squamous cell carcinoma: a prospective cohort study

Abstract

Abstract Objective: To investigate the accuracy of Medical Benefit Schedule (MBS) item numbers to identify treatments for basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). Methods: We linked records from QSkin Study participants (n=37,103) to Medicare. We measured the proportion of Medicare claims for primary excision of BCC/SCC that had corresponding claims for histopathology services. In subsets of participants, we estimated the sensitivity and external concordance of MBS item numbers for identifying BCC/SCC diagnoses by comparing against ‘gold‐standard’ histopathology reports. Results: A total of 2,821 (7.6%) participants had 4,830 separate Medicare claims for BCC/SCC excision; almost all (97%) had contemporaneous Medicare claims for histopathology services. Among participants with BCC/SCC confirmed by histology reports, 76% had a corresponding Medicare claim for primary surgical excision of BCC/SCC. External concordance for Medicare claims for primary BCC/SCC excision was 68%, increasing to 97% when diagnoses for intra‐epidermal carcinomas and keratoacanthomas were included. Conclusions: MBS item numbers for primary excision of BCC/SCC are reasonably reliable for determining incident cases of keratinocyte skin cancers, but may underestimate incidence by up to 24%. Implications: Medicare claims data may have utility in monitoring trends in conditions for which there is no mandatory reporting.

Keywords

• Medicare
• basal cell carcinoma
• squamous cell carcinoma
• keratinocyte cancers
• Medical Benefits Scheme
• sensitivity