Table 4

Comparisons between the means and sd of the predicted values for the control group as derived from the equations and the measured values

Parameter	Aged <21 yrs				Aged ≥21 yrs
Parameter	Measured	Predicted	p‐value	Residuals (absolute)	Measured	Predicted	p‐value	Residuals (absolute)
Females
FVC^#	2.88±0.90	2.88±0.84	0.94	0.02±0.21	3.17±0.55	3.19±0.43	0.19	0.02±0.35
FEV₁^#	2.56±0.80	2.55±074	0.64	0.01±0.31	2.78±0.47	2.79±0.38	0.49	0.01±0.28
FEV₁/FVC %	88.89±3.08	88.53±0.40	0.19	0.35±3.05	88.02±2.73	87.93±1.12	0.53	0.08±2.54
PEF^¶	5.73±1.95	5.52±1.54	0.02	0.21 ±1.01	6.77±1.28	6.86±0.64	0.09	0.09±1.1
FEF_25–75^¶	3.27±1.12	3.24±0.90	0.58	0.11±0.84	3.74±0.59	3.71±0.36	0.14	0.03±0.45
FEF₂₅^¶	5.23±1.70	5.34±1.41	0.11	0.12±0.83	6.24±1.1	6.30±0.52	0.22	0.05±0.95
FEF₅₀^¶	3.76±1.29	3.72±1.03	0.53	0.04±0.75	4.60±0.74	4.59±0.34	0.75	0.01±0.67
FEF₇₅^¶	1.77±0.75	1.76±0.51	0.77	0.01±0.54	1.71±0.51	1.72±0.28	0.69	0.01±0.40
Males
FVC^#	3.31±1.42	3.32±1.34	0.74	0.01±0.39	4.68±0.74	4.64±0.56	0.11	0.04±0.53
FEV₁^#	2.94±1.27	2.92±1.17	0.319	0.28±0.23	4.05±0.63	4.01±0.50	0.03	0.04±0.41
FEV₁/FVC %	88.88±3.14	88.28±0.36	0.012	0.59±3.19	86.76±3.24	86.55±1.24	0.14	0.21±2.95
PEF^¶	6.56±3.21	6.51±2.65	0.63	0.05±1.54	10.58±2.49	10.28±0.85	0.01	0.29±2.32
FEF_25–75^¶	3.71±1.65	3.55±1.41	0.08	0.50±0.45	4.94±0.82	4.93±0.52	0.61	0.02±0.67
FEF₂₅^¶	5.73±2.52	5.74±2.25	0.89	0.01±1.14	9.09±1.8	9.11±0.66	0.90	0.01±1.7
FEF₅₀^¶	4.06±1.76	4.07±1.58	0.88	0.01±0.68	6.02±0.92	6.04±0.48	0.63	0.02±0.84
FEF₇₅^¶	1.94±0.97	1.89±0.74	0.01	0.45±0.48	2.25±0.60	2.23±0.38	0.28	0.03±0.47

Data are presented as mean±sd unless otherwise stated
FVC: forced vital capacity
FEV₁: forced expiratory volume in one second
PEF: peak expiratory flow
FEF_25–75: expiratory flow from 25–75% of the vital capacity
FEF₂₅, FEF₅₀, FEF₇₅: instantaneous expiratory flows at 25%, 50% and 75% of FVC respectively
^#: volume are in L
^¶: flows are in L·s⁻¹