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

BMC Pulmonary Medicine

Table 2 Validity of restrictive spirometric pattern (RSP) 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_LLN (n = 33)
Sensitivity	0.33	0.20–0.48	0.34	0.20–0.46
Specificity	0.98	0.97–0.99	0.98	0.97–0.99
PPV	0.45	0.28–0.64	0.55	0.36–0.72
NPV	0.97	0.97–0.95	0.96	0.95–0.97
LR+	17.0	9.2–31.5	21.1	11.3–39.4
LR-	0.69	0.56–0.84	0.67	0.55–0.81
RSP_0.7 (n = 31)
Sensitivity	0.30	0.18–0.46	0.32	0.28–0.60
Specificity	0.98	0.98–0.97	0.98	0.97–0.99
PPV	0.45	0.27–0.64	0.55	0.36–0.73
NPV	0.97	0.95–0.98	0.96	0.95–0.97
LR+	16.8	8.8–31.9	21.3	11.1–40.9
LR-	0.71	0.59–0.86	0.69	0.57–0.83
RSP_PREDIL (n = 33)
Sensitivity	0.30	0.18–0.46	0.36	0.23–0.50
Specificity	0.98	0.97–0.99	0.98	0.97–0.99
PPV	0.42	0.25–0.61	0.58	0.39–0.75
NPV	0.97	0.95–0.98	0.96	0.95–0.98
LR+	15.0	8.1–28.0	23.8	12.7–44.9
LR-	0.71	0.59–0.86	0.65	0.53–0.80

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

ISSN: 1471-2466