Cardiac stress reactions and perseverance: Diminished reactivity is associated with study non-completion

Blunted cardiovascular stress reactions may be a marker for poor behavioral regulation. The present study examined the association between heart rate reactivity and perseverance, operationalized as the failure to complete a subsequent follow-up assessment. The heart rate (using electrocardiography), cardiac output (using Doppler echocardiography) and blood pressure (using a semi- automatic sphygmomanometer) of 176 high school students were measured before and during exposure to a standard 10-min mental arithmetic stress. A year later, all participants were contacted to complete a simple and undemanding on-line assessment. Despite repeated promptings, 44 failed to do so. Diminished heart rate and cardiac output stress reactions predicted failure to complete the follow-up. This result adds to the emerging characterization of those who exhibit blunted stress reactions by revealing associated deficiencies in perseverance. It may also have prognostic implications for the completion of multi-session interventions, as well as for selection bias in stress reactivity studies with follow-up designs.