Restrictive spirometric pattern and true pulmonary restriction in a general population sample aged 50 - 64 years

BMC Pulmonary Medicine

Table 3 Validity of restrictive spirometric pattern using slow vital capacity (RSP_LLNSVC and RSP_0.7SVC) in relation to true pulmonary restriction

Restrictive spirometric pattern (RSP)	True pulmonary restriction
	TLC < LLN₅ (Quanjer) (n = 46)		TLC < LLN₅ (Gothenburg) (n = 53)
	Value	95% CI	Value	95% CI
RSP_LLNSVC (n = 33)
Sensitivity	0.24	0.13–0.39	0.26	0.15–0.40
Specificity	0.99	0.98–0.99	0.99	0.98–1.00
PPV	0.52	0.30–0.74	0.67	0.43–0.85
NPV	0.96	0.95–0.97	0.96	0.94–0.97
LR+	22.4	9.2–31.5	35.1	14.8–83.3
LR-	0.77	0.56–0.84	0.74	0.63–0.87
RSP_0.7DSVC (n = 31)
Sensitivity	0.22	0.11–0.36	0.21	0.11–0.34
Specificity	0.99	0.98–1.00	0.99	0.98–1.00
PPV	0.56	0.31–0.78	0.61	0.36–0.83
NPV	0.96	0.95–0.97	0.96	0.94–0.97
LR+	25.4	10.6–61.5	27.6	11.1–68.3
LR-	0.79	0.68–0.92	0.80	0.70–0.92

Definition of abbreviations: LLN Lower limit of normal; total lung capacity; PPV Positive predictive value, NPV Negative predictive value, LR+ Positive likelihood ratio, LR- Negative likelihood ratio, SVC Slow vital capacity

ISSN: 1471-2466