No association between non-steroidal anti-inflammatory drugs and acute appendicitis in a case-control study

Background: A recent case-control study reported an association between non-steroidal antiinflammatory drug (NSAID) use and acute appendicitis. This association was investigated in a case-control study of patients, aged 30 years and over, admitted as an emergency to hospitals in Tayside between 1989 and 1992, who had appendicectomy for acute appendicitis.

Methods: A record-linkage database containing records of dispensed prescriptions and hospital admissions was used. A total of 223 patients were identified. The medical records of 161 were checked, of which 138 were valid cases, and information on white cell count and NSAID exposure was recorded. Community and hospital controls were generated.

Results: Some 9.0 per cent of patients were prescribed NSAIDs within 90 days of hospitalization, compared with 7.6 per cent of community controls and 11.5 per cent of hospital controls. The odds ratio was 1.21 (95 per cent confidence interval 0.73-2.01) and 0.75 (0.43-1.32) respectively. There was no significant difference in white cell count between exposed and non-exposed cases. No increased risk of appendicectomy was associated with aspirin use: odds ratio 1.67 (0.52-5.30) and 0.37 (0.12-1.13) using community and hospital controls respectively.

Conclusion: Appendicectomy for acute appendicitis is not associated with increased prior use of NSAIDs.