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. Author manuscript; available in PMC: 2021 Oct 21.
Published in final edited form as: Int Rev Psychiatry. 2019 May 14;31(7-8):637–645. doi: 10.1080/09540261.2019.1586324

Table 3:

Associations of altitude as a categorical variable and change in altitude as a categorical variable and depression, anxiety, and suicidality among participants in the Intern Health Study (N = 3,731). Statistically significant associations (p < 0.05) are shown in bold text; “ref.” indicates a reference value for the parameter.

Altitude of residency as a categorical variable
PHQ-9 Total Score GAD-7 Total Score Any Suicidal Ideation (PHQ-9 Item #9 >0)
Parameter OR 95% CI P OR 95% CI P OR 95% CI P
Low altitude (<900m) ref. - - - ref. - - - ref. - - -
High altitude (≥900m) 1.32 1.00 1.75 <0.05 1.27 1.06 1.72 0.1 1.79 1.08 2.97 0.02
Baseline depression 7.48 5.58 10.0 <.0001 4.10 3.18 5.29 <.0001 5.08 3.57 7.22 <.0001
Age 1.01 0.993 1.04 0.2 1.00 0.98 1.02 0.7 1.02 0.977 1.06 0.4
Sex (=F) 1.48 1.32 1.65 <.0001 1.57 1.41 1.75 <.0001 0.953 0.767 1.19 0.7
Caucasian race 0.993 0.890 1.11 0.9 1.12 1.01 1.25 0.04 0.740 0.591 0.927 0.01
Baseline anxiety 3.80 2.83 5.10 <.0001 7.82 5.87 10.4 <.0001 2.89 1.98 4.21 <.0001
Personal history of depression 2.07 1.86 2.31 <.0001 1.95 1.75 2.17 <.0001 2.70 2.15 3.38 <.0001
Average sleep in last week 0.727 0.690 0.766 <.0001 0.787 0.748 0.828 <.0001 0.914 0.835 1.00 0.05
Change in altitude between medical school and residency as a categorical variable
PHQ-9 Total Score GAD-7 Total Score Any Suicidal Ideation (PHQ-9 Item #9 >0)
Parameter OR 95% CI P OR 95% CI P OR 95% CI P
Staying at low altitude ref. - - - ref. - - - ref. - - -
Staying at high altitude 0.840 0.459 1.54 0.6 0.887 0.478 1.64 0.7 0.947 0.852 1.05 0.3
Moving from high to low altitude 1.27 0.893 1.82 0.2 1.36 0.934 1.98 0.1 1.08 0.974 1.21 0.1
Moving from low to high altitude 1.47 1.09 1.98 0.01 1.40 1.00 1.95 <0.05 1.10 1.01 1.19 0.02
Baseline depression 7.53 5.62 10.1 <.0001 4.11 3.19 5.29 <.0001 1.54 1.36 1.75 <.0001
Age 1.01 0.990 1.04 0.3 1.00 0.981 1.02 0.9 1.00 1.00 1.01 0.4
Sex (=F) 1.48 1.32 1.65 <.0001 1.57 1.41 1.75 <.0001 0.989 0.970 1.01 0.2
Caucasian race 0.986 0.885 1.10 0.8 1.11 1.00 1.24 <0.05 0.972 0.952 0.992 0.01
Baseline anxiety 3.74 2.79 5.02 <.0001 7.69 5.75 10.3 <.0001 1.24 1.12 1.37 <.0001
Personal history of depression 0.484 0.435 0.539 <.0001 0.516 0.465 0.573 <.0001 0.930 0.913 0.947 <.0001
Average sleep in last week 0.724 0.688 0.762 <.0001 0.784 0.746 0.824 <.0001 0.992 0.984 1.00 0.04