Psychiatric caseness is a marker of major depressive episode in general practice

Figures & data

Table I. Distribution of patients in four diagnostic subgroups.

MDE	Denmark	Finland	Sweden	Norway
	% (95% CI)	% (95% CI)	% (95% CI)	% (95% CI)
True positives	3.1 (2.5–3.6)	3.0 (1.8–4.1)	3.3 (2.2–4.3)	2.7 (1.8–3.6)
False positives	12.4 (11.2–13.5)	16.4 (13.8–19.1)	15.3 (13.0–17.6)	25.2 (22.3–28.0)
True negatives	82.1 (80.7–83.5)	79.1 (76.0–82.2)	80.1 (77.6–82.6)	71.3 (68.3–74.3)
False negatives	2.5 (2.0–2.9)	1.5 (0.8–2.3)	1.3 (0.7–2.0)	0.9 (0.4–1.3)
Patients in total	4.271	1.180	1.283	1.720

Notes: The four diagnostic subgroups were defined on the basis of patients' DSQ results and GPs' MDE diagnoses for Denmark, Finland, Sweden, and Norway respectively. The numbers represent proportion (%) of patients classified in each subgroup out of the total number of patients in each country. Parentheses represent 95% confidence intervals. The 95% confidence intervals were adjusted for GP clusters (correlation between the multiple judgements from each GP).

Table II. Comparison of sensitivity, specificity and diagnostic accuracy.

	Denmark	Finland	Sweden	Norway
MDE
Sensitivity	0.56 (0.49–0.62)	0.66 (0.53–0.79)	0.71 (0.60–0.83)	0.75 (0.65–0.86)
Specificity	0.87 (0.86–0.88)	0.83 (0.81–0.85)	0.84 (0.82–0.86)	0.74 (0.72–0.76)
Youden Index	0.42 (0.36–0.49)	0.49 (0.36–0.62)	0.55 (0.43–0.67)	0.49 (0.38–0.60)
Psychiatric Case
Sensitivity	0.79 (0.74–0.84)	0.92 (0.85–1.00)	0.90 (0.82–0.98)	0.85 (0.76–0.94)
Specificity	0.74 (0.73–0.75)	0.49 (0.46–0.52)	0.42 (0.39–0.44)	0.63 (0.61–0.66)
Youden Index	0.53 (0.48–0.59)	0.42 (0.34–0.49)	0.31 (0.23–0.40)	0.49 (0.39–0.58)

Notes: MDE: Sensitivity and specificity of GPs' MDE diagnoses in Denmark, Finland, Norway, and Sweden. Diagnostic performance is expressed as the Youden Index. Parentheses represent 95% confidence intervals. Psychiatric case: Sensitivity, specificity, and Youden Index of the comparison between patients' psychiatric case status, as evaluated by the GP, and their DSQ status.