title: Job strain and heart rate variability in resident physicians within a general hospital.
abstract: OBJECTIVE
  To evaluate the association of heart rate variability with job strain in first year resident physicians.
  
  
  METHODS
  We performed the study at the "Manuel Gea González" General Hospital in Mexico City. 54 resident doctors were studied over a period of 24 hr in their first year of specialization. Two questionnaires were administered: the first on general demographics, and the second, the Job Content Questionnaire. Heart rate variability was evaluated through the frequency domain (low-frequency power, high-frequency power, and low-frequency power/high-frequency power ratio) and time domain (SDNN). The doctors wore a Holter monitor over a 24-hr period, which included a workday plus their on-call time. They recorded their activities in a log.
  
  
  RESULTS
  Compared to physicians in the "low strain" category, physicians working in the "passive" category had lower overall peak-to-peak cardiac variability (standard deviation of N-N intervals, SDNN), -9.08% (95% CI -17.97, 0.74), a -25% (95% CI -45.00, 0.22) lower high-frequency power, and -26.95% (95% CI -39.00, -12.53) lower low-frequency power. Physicians working in the "high strain" category had lower low-frequency power, -17.85% (95%CI -32.34, -0.25), and lower low-frequency/high-frequency ratio -24.29% (95% CI 38.08, 7.42) compared to those in the "low strain" category.
  
  
  CONCLUSIONS
  High job strain and low job control among medical residents were associated with several indicators of lowered heart rate variability. Thus, analysis of heart rate variability may be an informative marker for evaluating the physiological impacts of workplace stressors.
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias, México, DF, Mexico.
authors.forename: Sendy Isarel
authors.initials: SI
authors.lastname: Hernández-Gaytan
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Rothenberg
authors.forename: Paul
authors.initials: P
authors.lastname: Landsbergis
authors.forename: Leonor Cedillo
authors.initials: LC
authors.lastname: Becerril
authors.forename: Guillermo
authors.initials: G
authors.lastname: De León-León
authors.forename: Sean M
authors.initials: SM
authors.lastname: Collins
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Díaz-Vásquez
mesh_terms: D000328:Adult; D002983:Clinical Competence; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006769:Hospitals, General; D006801:Humans; D007389:Internal-External Control; D007396:Internship and Residency; D008297:Male; D017009:Professional Autonomy; D013038:Specialization; D013315:Stress, Psychological / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D017132:Workplace / Q000523:psychology*; D055815:Young Adult