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Table 2 Psychometric properties of the PHQ disorder in a high-risk sample (weighted) and a GP-identified sample

From: Screening high-risk patients and assisting in diagnosing anxiety in primary care: the Patient Health Questionnaire evaluated

 

High-risk sample (N = 170)

GP-identified sample (N = 141)

 

Official algorithma

Screening questionsb

Official algorithma

Screening questionsb

Cross-tabulation

a

b

c

d

a

b

c

d

a

b

c

d

a

b

c

d

 

25

8

42

95

49

15

12

93

73

3

40

25

106

21

7

7

Prevalence

0.39 (67/170)

 

0.36 (61/170)

0.80 (113/141)

0.80 (113/141)

Positive predictive value

0.77 (25/32)

0.76 (49/64)

0.96 (73/76)

0.84 (106/127)

[0.71–0.83]

[0.70–0.83]

[0.93–0.99]

[0.77–0.90]

Negative predictive value

0.69 (95/138)

0.88 (93/105)

0.38 (25/65)

0.50 (7/14)

[0.62–0.76]

[0.83–0.93]

[0.30–0.46]

[0.42–0.58]

Positive likelihood ratio

5.1 [4.41–5.79]

5.71 [4.93–6.49]

6.03 [5.12–6.94]

1.25 [1.16–1.35]

Negative likelihood ratio

0.68 [0.61–0.75]

0.23 [0.17–0.30]

0.40 [0.32–0.48]

0.25 [0.18–0.32]

Sensitivity

0.37 (25/67)

0.80 (49/61)

0.65 (73/113)

0.94 (106/113)

[0.30–0.44]

[0.74–0.86]

[0.57–0.72]

[0.90–0.98]

Specificity

0.93 (95/103)

0.86 (93/108)

0.89 (25/28)

0.25 (7/28)

[0.89–0.97]

[0.81–0.91]

[0.84–0.94]

[0.18–0.32]

Overall accuracy

0.71 (95 + 25/170)

0.84 (93 + 49/170)

0.70 (73 + 25/141)

0.80 (106 + 7/141)

[0.64–0.78]

[0.78–0.89]

[0.62–0.77]

[0.74–0.87]

Area under the curve

0.65*

0.83*

0.77 [0.68–0.86]

0.60 [0.47–0.72]

[0.64–0.66]

[0.82–0.84]

  
  1. a: true positives, b: false positives, c: false negatives, d: true negatives, a Official algorithm panic disorder: All the first four questions were answered with “yes” and four symptoms related to panic attacks are present. Official algorithm general anxiety: The first question was answered with “more than half the days” and three symptoms related to general anxiety were present more than half the days. b Screening question for panic disorder (“In the last 4 weeks, have you had an anxiety attack - suddenly feeling fear or panic?”) was answered with yes AND/OR screening question for general anxiety (“Feeling nervous, anxious, on edge, or worrying a lot about different things”) was answered with “more than half the days”. *Because weighting in the receiver operating characteristics (ROC) analysis is only possible with integer values, the weights were multiplied by 100).
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BMC Psychiatry

ISSN: 1471-244X

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