Outcome definition2 Exposure: Eczema1 Exposure: Psoriasis1
OR (95%CI)3 n4 OR (95%CI)3 n4
UK Biobank
depression Interview-reported diagnosis 1.36 (1.27-1.45) 229,393 1.11 (1.01-1.21) 229,371
anxiety Interview-reported diagnosis 1.30 (1.14-1.47) 229,393 1.29 (1.08-1.52) 229,371
depression PHQ-9 ≥ 10 (survey) 1.24 (1.09-1.39) 69,420 1.19 (1.00-1.41) 69,417
anxiety GAD-7 ≥ 10 (survey) 1.20 (1.05-1.37) 69,737 1.19 (0.98-1.44) 69,734
Primary care
depression ≥ 1 diagnosis pre-interview 1.56 (1.50-1.62) 229,378 1.38 (1.31-1.46) 229,356
anxiety ≥ 1 diagnosis pre-interview 1.53 (1.46-1.60) 229,390 1.38 (1.29-1.47) 229,368
depression ≥ 1 diagnosis pre-survey 1.50 (1.39-1.63) 64,499 1.37 (1.22-1.54) 64,496
anxiety ≥ 1 diagnosis pre-survey 1.43 (1.30-1.58) 64,502 1.39 (1.21-1.59) 64,499
1 Exposures defined using self-reported previous diagnosis at the UK Biobank recruitment interview, or through records in primary care prior to the timepoint (at least 1 diagnosis + 2 prescription codes on separate days for eczema; 1 diagnosis for psoriasis).
2 At the Initial interview timepoint (in grey), outcomes are defined either as a self-reported previous doctor's diagnosis, or at least 1 diagnosis code in primary care prior to the interview. At the 2016 mental health follow-up survey (70,878 responded), outcomes are defined either as a score of ≥10 in the PHQ-9 score for depression/the GAD-7 score for anxiety, which take into account symptoms in the 2 weeks prior to the survey, or at least 1 diagnosis code in primary care prior to the follow-up survey
3 Odds ratios (95% confidence intervals) estimated from logistic regression for having a mental illness (adjusted for age, sex, deprivation and ethnicity) comparing people with the respective skin disease to people without the respective skin disease
4 Number of observations that went into the model. Observations with missing values were dropped. "Prefer not to answer" and "Do not know" were treated as missing values. For the follow-up survey timepoint, only used GP data where all of the questions of the mental health follow-up survey were answered