Table 1. Demographic Characteristics of Patients Included in the Overall Cohort and the 4 Subsets (1998 to 2011)
CharacteristicsOverall Cohort (n = 32,385)HPI Subset (n = 15,761)PHQ-9 Subset (n = 1,013)HPI or PHQ-9 Subset (n = 16,289)Both HPI & PHQ-9 Subset (n = 485)
Female sex6867676767
Age (years), mean (median), range61 (65), 13–9860.4 (63), 13–9854.2 (55), 15–9660.2 (17.9), 13–9853.1 (53), 15–94
Age group
    Adolescent (13–18 years old)1.11.10.71.11.2
    Adult (19–64 years old)48.450.568.751.169.3
    Older adult (≥65 years old)50.548.430.6.47.829.5

  • Data are percentages unless otherwise indicated.

  • HPI, history of present illness; PHQ-9, 9-item Patient Health Questionnaire.