Cardiovascular risk score and cardiovascular events among airline pilots: a case-control study

A cardiovascular risk prediction score is routinely applied by aviation authorities worldwide. We examined the accuracy of the Framingham-based risk chart used by the New Zealand Civil Aviation Authority in predicting cardiovascular events among airline pilots.

A matched case-control design was applied to assess the association of 5-yr cardiovascular risk score and cardiovascular events in Oceania-based airline pilots. Cases were pilots with cardiovascular events as recorded on their medical records. Each case was age and gender matched with four controls that were randomly selected from the pilot population. To collect data before the events, 5-yr retrospective evaluations were conducted.

Over a 16-yr study period we identified 15 cases of cardiovascular events, 9 (60%) of which were sudden clinical presentations and only 6 (40%) of which were detected using cardiovascular screening. There were 8 cases (53%) and 16 controls (27%) who had a 5-yr risk of > or = 10-15%. Almost half of the events (7/15) occurred in pilots whose highest 5-yr risk was in the 5-10% range. Cases were 3.91 times more likely to have highest 5-yr risk score of > or =10-15% than controls (OR = 3.91, 95% CI 1.04-16.35). The accuracy of the highest risk scores were moderate (AUC = 0.723, 95% CI 0.583-0.863). The cutoff point of 10% is valid, with a specificity of 0.73, but low sensitivity (0.53).

Despite a valid and appropriate cutoff point, the tool had low sensitivity and was unable to predict almost half of the cardiovascular events.