Clinical Correlates of a Single-item Physical Activity Questionnaire among Patients Undergoing Stress SPECT Myocardial Perfusion Imaging.

Background: There has been an increasing call for employing ultrashort exercise activity questionnaires as a clinical "vital sign". To-date, this has not been applied to patients undergoing cardiac stress testing.

Methods: We evaluated 1,136 patients who completed a one-item exercise questionnaire before undergoing stress SPECT myocardial perfusion imaging (MPI). This question asked patients to grade how much they exercise during daily life on an 11-point scale (0= none, 10 = always). Patients were divided into four exercise activity groups based on their response: no, low, moderate, and high exercise activity. The results of this questionnaire were compared to patients clinical risk profile, mode of stress testing (exercise versus pharmacologic), and exercise treadmill duration.

Results: We noted a stepwise inverse relationship between exercise activity and patients' frequency of hypertension, diabetes, and obesity (p<0.001 for each). Patients with no reported exercise activity were more likely to complain of dyspnea. There was a stepwise increase in the number of patients performing treadmill exercise with increasing reported exercise activity (p<0.001). The duration on treadmill exercise increased in stepwise fashion with higher patient reported exercise activity (p<0.001).

Conclusion: Our single-item, self-reported questionnaire was correlated to patients' risk profiles, their mode of stress testing, and cardiorespiratory fitness. These correlates, along with the pragmatic nature of this ultrashort questionnaire, and its built-in identification of patients who may warrant exercise counseling, augurs for adopting ultrashort questionnaires regarding exercise activity among patients undergoing stress MPI and other cardiac imaging tests where functional capacity is not routinely assessed.