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Table 1 Average points and reliability of PHQ-9 items according to the prevalence of depression

From: Low fruit and vegetable intake is associated with depression among Korean adults in data from the 2014 Korea National Health and Nutrition Examination Survey

Patient Health Questionnaire-9

Non-depression1 (n = 4050)

Depression2 (n = 299)

Total (n = 4349)

Mean

SE

Mean

SE

Mean

SE

1. Little interest or pleasure in doing things

0.33

0.01

1.7

0.1

0.4

0.01

2. Feeling down, depressed, or hopeless

0.2

0.01

1.8

0.1

0.3

0.01

3. Trouble falling or staying asleep or sleeping too much

0.4

0.02

2.2

0.1

0.6

0.02

4. Feeling tired or having little energy

0.6

0.02

2.4

0.1

0.7

0.02

5. Poor appetite or overeating

0.2

0.01

1.5

0.1

0.3

0.01

6. Feeling bad about yourself—or that you are a failure or have let yourself or your family down

0.1

0.01

1.5

0.1

0.2

0.01

7. Trouble concentrating on things, such as reading the newspaper or watching television

0.1

0.01

1.0

0.1

0.1

0.01

8. Moving or speaking so slowly that other people could have noticed. Or the opposite, being so fidgety or restless that you have been moving around a lot more than usual

0.04

0.004

0.8

0.1

0.1

0.01

9. Thoughts that you would be better off dead or of hurting yourself in some way

0.05

0.004

0.9

0.1

0.1

0.01

Total score

2.1

0.04

13.8

0.2

2.8

0.1

Cronbach’s α

0.808

  1. 1Total score of PHQ (Patient Health Questionnaire)-9 < 10
  2. 2Total score of PHQ-9 ≧ 10
  3. 3Q. 1–9. Score (0: Not at all, 1: Several days, 2: More than half the days, 3: Every day)