Identification of esophageal cancer in the General Practice Research Database.

Area of Science:

• Oncology
• Pharmacoepidemiology
• Health Informatics

Background:

• Conflicting results exist regarding bisphosphonate use and esophageal cancer onset based on General Practice Research Database (GPRD) codes.
• Limited literature addresses the accuracy of cancer code timing in general practice records compared to clinical onset.

Purpose of the Study:

• To evaluate the accuracy of esophageal cancer codes within the GPRD.
• To determine if clinical onset dates can be reliably inferred from GPRD data.

Main Methods:

• A systematic review of women's GPRD records (1996-2008) with esophageal cancer codes was conducted.
• General practices were consulted for 75 confirmed esophageal cancer cases and 25 controls to validate findings.

Main Results:

• The vast majority of cases with an esophageal cancer code were confirmed.
• In 89% of cases with available data, clinical onset aligned with the recorded date within 60 days.
• Clinical onset preceded coding by over six months in 10% of cases, with 25% lacking sufficient data for dating.

Conclusions:

• GPRD coding for esophageal cancer in women is generally accurate for diagnosis.
• Precise clinical onset and diagnosis timing in GPRD may necessitate manual review of clinical records.
• Future research should consider linkage with cancer registries for improved temporal accuracy.